electronics installation and maintenance book - us coast guard home

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NAVSEA SEOOO-OO-EIM-160

ELECTRONICS

INSTALLATION

AND

MAINTENANCE BOOK

GENERAL

MAINTENANCE

..

Publiskf by direction ofCOMMANDER, NAVAL SEA SYSTEMS COMMAND

FOR

1 JANUARY 1981OFFICIAL USE ONLY

FRONT MATTER NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

Dates of issue for original and changed pages are:

Ori9inal. ..0. . . 1 January 1981

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 172 CONSISTING OF THE FOLLOWING:

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A ORIGINAL

GENERAL MAINTENANCE N A V S E A S E O O O - O O - E I M - 1 6 0 J A N U A R Y 1 9 8 1

I N S T R U C T I O N S H E E T

1. T h e e n c l o s e d m a t e r i a l c o n s t i t u t e s a c o m p l e t e r e v i s i o n t o t h eG e n e r a l M a i n t e n a n c e C h a p t e r o f t h e E l e c t r o n i c s I n s t a l l a t i o n a n dM a i n t e n a n c e B o o k .

2 . R e m o v e a l l e x i s t i n g p a g e s o f S e c t i o n s 1 t h r o u g h 6 a n d t h eF r o n t M a t t e r o f t h e G e n e r a l M a i n t e n a n c e H a n d b o o k , N A V S H I P S 0 9 6 7 -0 0 0 - 0 1 6 0 a n d r e p l a c e w i t h t h i s p a c k a g e , N A V S E A SEOOO-00-EIM-160d a t e d J a n u a r y 1 9 8 1 .

3 . C h e c k e a c h p a g e o f t h i s p a c k a g e a g a i n s t t h e L i s t o f E f f e c t i v eP a g e s t o b e s u r e t h a t a l l n e w p a g e s a r e i n c l u d e d . M i s s i n g p a g e ss h o u l d b e r e p o r t e d t o t h i s o f f i c e b y u s i n g t h e C o m m e n t S h e e t sp r o v i d e d a s t h e l a s t p a g e s o f t h e h a n d b o o k .

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GENERAL MAINTENANcE NAVSEA SEOOO-OO-EIM-160 CHANGES

RECORD OF CHANGES

CHANGEDATE T I T L E O R B R I E F

NO. DESCR I PT 10N ENTERED BY

NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

ORIGINAL

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GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 FRONT MATTER

BOX SCOREGENERAL MAINTENANCE NAVSEA 0967-LP-OOO-O160

I IEDITION PUBLICATION

DATE

I BasicI

I I

Change 9(2) (2)

STOCK LATEST EIBNUMBER COVERED(1)

0967. LP-000-0160 024

(2)

NOTES

(1) The number listed in this column indicates that this handbook issue incorporates information fromEIB issues up to and including the one shown.

(2) This change reserved for Tab Separator Package.

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ORIGINAL i/ii BLANK i / i i B L A N K

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GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160

TABLE OF CONTENTS

CONTENTS

Paragraph Page

SECTION 1 – INTRODUCTION

1-1 Purpose. . . . . . . . . . . . . . . . . . . . . . . . 1-1

1-2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-2.1 Experienced Technician. . . . . . . . . 1-11-2.2 Technician Out-Of-School . . . . . . . 1-11-2.3 Trainee. . . . . . . . . . . . . . . . . . . . 1-1

1-3 Organization. . . . . . . . . . . . . . . . . . . . . 1-1

SECTION 2 – MAINTENANCE CONCEPTS

2-1 Introduction. . . . . . . . . . . . . . . . . . . . . 2-1

2-2 Preventive Maintenance Programs. . . . . . . 2-12-2.1 POMSEE Program. . . . . . . . . . . . . 2-22-2.1.1 Reference Standards Test. . . . . . . 2-22-2.1.2 Reference Standards Summary

Sheets . . . . . . . . . . . . . . . . . . . 2-22-2.1.3 Performance Standards Sheets . . . 2-32-2.2 Maintenance and Material

Management System . . . . . . . . . . . 2-32-2.2.1 Planned Maintenance System . . . . 2-32-2.2.1.1 Maintenance Index Page . . . . . . 2-32-2.2.1.2 Maintenance Requirement Card . 2-52-2.2.1.3 Equipment Guide List . . . . . . . 2-72-2.2.1.4 Cycle Schedule . . . . . . . . . . . . 2-72-2.2.1.5 Quarterly Schedule . . . . . . . . . 2-82-2.2.1.6 Weekly Schedule . . . . . . . . . . . 2-122-2.2.1.7 Maintenance Control Board. . . . 2-122-2.2.2 Maintenance Data Collection System 2-122-2.2.2.1 PMS Feedback Report . . . . . . . 2-142-2.2.2.2 Maintenance Data Form . . . . . . 2-142-2.2.2.3 Supplemental Report Form. . . . 2-142-2.2.2.4 Work Supplement Card. . . . . . . 2-142-2.2.2.5 Failed Parts/Components Card. . 2-172-2.2.2.6 Single Line Item Requisition

Document . . . . . . . . . . . . . . . 2-172-2.2.2.7 Single Line Item Consumption/

Management Document . . . . . . 2-21

2-3 Operational Maintenance . . . . . . . . . . . . 2-222-3.1 Operator Responsibilities . . . . . . . . 2-222-3.2 Technician Responsibilities. . . . . . . 2-23

2-4 Troubleshooting for Corrective Maintenance 2-232-4.1 Symptom Recognition. . . . . . . . . . 2-232-4.2 Symptom Elaboration . . . . . . . . . . 2-23

Paragraph Page

2-4.3 Listing Probable Faulty Functions . . 2-232-4.4 Localizing the Faulty Function . . . . 2-232-4.5 Localizing Trouble to the Circuit. . . 2-232-4.5.1 Waveform Analysis. . . . . . . . . . . 2-2424.5.2 Voltage Checks . . . . . . . . . . . . . 2-242-4.5.3 Resistance Checks . . . . . . . . . . . 2-2424.5.4 Tube Testing. . . . . . . . . . . . . . . 2-242-4.5.5 Semiconductor Testing . . . . . . . . 2-242-4.6 Failure Analysis . . . . . . . . . . . . . . 2-24

2-5 Alterations. . . . . . . . . . . . . . . . . . . . . . 2-252-5.1 SHIPALTS . . . . . . . . . . . . . . . . . 2-252-5.2 ORDALTS . . . . . . . . . . . . . . . . . 2-25

2-6 Field Changes. . . . . . . . . . . . . . . . . . . . 2-262-6.1 Classes of Field Changes. . . . . . . . . 2-262-6.2 Types of Field Changes . . . . . . . . . 2-262-6.3 Recording and Reporting

Accomplishment of Field Changes . . 2-26

SECTION 3 – ROUTINE MAINTENANCEAND MAINTENANCE AIDS

3-1 Safety Precautions. . . . . . . . . . . . . . . . . 3-1

3-2 Routine Maintenance. . . . . . . . . . . . . . . 3-13-2.1 Cleaning and Inspection. . . . . . . . . 3-13-2.1.1 Ultrasonic Cleaning. . . . . . . . . . . 3-13-2.1.2 Ultrasonic Cleaning of Modular

Assemblies . . . . . . . . . . . . . . . . 3-33-2.1.3 Cleaning Solvent Hazards. . . . . . . 3-63-2.1.4 Cleaning of Air Filters. . . . . . . . . 3-73-2.1.5 Cleaning of Transistor Heat Sinks . 3-73.2.2 Lubrication . . . . . . . . . . . . . . . . . 3-73.2.2.1 Lubrication of Ball Bearings. . . . . 3-73-2.2.1.1 Greasing. . . . . . . . . . . . . . . . . 3-83-2.2 .1.1.1 Grease Cups. . . . . . . . . . . . . 3-83-2.2 .1.1.2 Selection of Grease . . . . . . . . 3-83.2.2 .1.1.3 Adding Grease . . . . . . . . . . . 3-83-2.2 .1.1.4 Renewal of Grease Without

Disassembling the BearingHousing. . . . . . . . . . . . . . . . 3-9

3-2.2 .1.1.5 Renewal of Grease with theBearing Housing Disassembled. 3-10

3-2.2 .1.1.6 Oil-Lubricated Ball Bearings . . 3-103-2.2.2 Lubrication of Sleeve Bearings . . . 3-103.2.2.3 Types of Lubricants . . . . . . . . . . 3-113-2.3 Environmental Effects on

Electronic Equipment . . . . . . . . . . 3-11

OR IGINAI . . .


TABLE OF CONTENTS (Continued)

Paragraph Page

3-2.3.1 Temperature . . . . . . . . . . . . . . . 3-113-2.3.2 Humidity . . . . . . . . . . . . . . . . . 3-113-2.3.3 Storage. . . . . . . . . . . . . . . . . . . 3-163-2.3.4 Standby Equipment . . . . . . . . . . 3-163-2.3.5 Corrosive Atmosphere. . . . . . . . . 3-163-2.3.6 Barometric Pressure Effects . . . . . 3-163-2.3.7 Vibration and Shock. . . . . . . . . . 3-17

3-3 Maintenance Aids . . . . . . . . . . . . . . . . . 3-173-3.1 Soldering Tools . . . . . . . . . . . . . . 3-173-3.1.1 Soldering Irons . . . . . . . . . . . . . 3-173-3.1.2 Pencil Irons. . . . . . . . . . . . . . . . 3-173-3.1.3 Soldering Guns . . . . . . . . . . . . . 3-193-3.2 Special Hand Tools . . . . . . . . . . . . 3-193-3.2.1 Punches . . . . . . . . . . . . . . . . . . 3-193-3.2.2 Taps . . . . . . . . . . . . . . . . . . . . 3-193-3.2.3 Dies. . . . . . . . . . . . . . . . . . . . . 3-213-3.2.4 Reamers. . . . . . . . . . . . . . . . . . 3-213-3.2.5 Countersinks. . . . . . . . . . . . . . . 3-213-3.2.6 Rotary Cutting Tools . . . . . . . . . 3-213-3.2.6.1 Circle Cutter. . . . . . . . . . . . . . 3-213-3.2.6.2 Hacksaws. . . . . . . . . . . . . . . . 3-243-3.2.6.3 Carbide Cutters. . . . . . . . . . . . 3-243-3.2.7 Wire and Thread Gauges . . . . . . . 3-243-3.2.7.1 Wire Gauges . . . . . . . . . . . . . . 3-243-3.2.7.2 Thread Gauges . . . . . . . . . . . . 3-243-3.2.8 Wire Strippers . . . . . . . . . . . . . . 3-243-3.2.9 Tube Puller. . . . . . . . . . . . . . . . 3-253-3.3 Reference Publications. . . . . . . . . . 3-253-3.3.1 Naval Ships Technical Manual. . . . 3-263-3.3.1.1 Scope . . . . . . . . . . . . . . . . . . 3-263-3.3.1.2 Distribution . . . . . . . . . . . . . . 3-263-3.3.2 Equipment Technical Manual . . . . 3-263-3.3.2.1 Distribution . . . . . . . . . . . . . . 3-283-3.3.3 Functionally Oriented

Maintenance Manual. . . . . . . . . . 3-293-3.3.4 Electronics Installation and

Information Books. . . . . . . . . . . 3-313-3.3.4.1 Scope . . . . . . . . . . . . . . . . . . 3-313-3.3.4.2 Distribution . . . . . . . . . . . . . . 3-313-3.3.5 Electronics Information Bulletin. . 3-32

3-4 Soldering and Repair Skills . . . . . . . . . . . 3-32

SECTION 4 – SOLDERING TECHNIQUES

4-1 Introduction. . . . . . . . . . . . . . . . . . . . . 4-1

4-2 Solder Types . . . . . . . . . . . . . . . . . . . . 4-1

Paragraph

4-3 Soldering Flux . . . . . . . . . . . . . . . . . . .

4-4 Metallic Platings . . . . . . . . . . . . . . . . . .44.1 Characteristics and Fabrication

of a Quality Solder Joint . . . . . . . .4-4.2 Recognition and Causes

of Solder Joint Defects . . . . . . . . .4-4.2.1 Causes of Common Defects . . . . .

4-5 Installation and Soldering of Components .4-5.1 Component Positioning . . . . . . . . .4-5.2 Component Lead Shaping. . . . . . . .4-5.3 Component Lead Termination. . . . .4-5.4 Circuit Board Preparation. . . . . . . .4-5.5 Proper Shaping Techniques. . . . . . .4-5.6 Solder Connection Characteristics . .4-5.7 High-Quality Soldering Techniques. .4-5.8 Application of Solder . . . . . . . . . .4-5.9 Cleaning After Soldering . . . . . . . .4-5.10 Quality Inspection Standards. . . . .4-5.11 Final Inspection . . . . . . . . . . . . .4-5.12 Conforrnal Coating Identification. .

4-6 Desoldenng and Removing Components . .4-6.1 Recognition of Solder Joint Types. .4-6.2 Identification Methods. . . . . . . . . .4-6.3 Resoldering Methods for Printed

Circuit Solder Joints . . . . . . . . . . .4-6.4 Selection and Use of

Desoldenng Tools. . . . . . . . . . . . .4-6.5 Inferior Methods of Solder

Extraction. . . . . . . . . . . . . . . . . .4-6.6 Wicking Procedures. . . . . . . . . . . .4-6.7 Manual Solder Extraction

Procedures. . . . . . . . . . . . . . . . . .4-6.8 Component Removal. . . . . . . . . . .4-6.9 Finrd Desoldenng Inspection. . . . . .

4-7 Soldering of Wire Terminals. . . . . . . . . . .4-7.1 Terminal Types, Sizes and Usages. . .4-7.2 Terminal Preparation for Soldering. .4-7.3 Conductor Preparation for Soldering4-7.4 Attachment of Conducto~

to Terminals . . . . . . . . . . . . . . . .4-7.5 Soldering of Conductors to

Terminals . . . . . . . . . . . . . . . . . .

4-8 Electrical Wire Splicing and Heat-ShrinkTubing . . . . . . . . . . . . . . . . . . . . . . . .

Page

4-2

4-2

4-3

4-34-3

4-34-34-34-44-44-44-44-54-54-54-54-64-6

4-74-74-7

4-7

4-9

4-94-9

4-94-1o4-1o

4-1o4-1o4-1o4-1o

4-11

4-11

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FRONT MATTER NAVSEA SEOOO-OO-EIM-160


CONTENTS

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Paragraph Page

4-8.1 Types of Splices . . . . . . . . . . . . . 4-114-8.2 Heat-Shrink Tubing. . . . . . . . . . . 4-14

4-9 Solderable Connector Pins. . . . . . . . . . . 4-144-9.1 Soldering Requirements. . . . . . . . 4-164-9.2 Application of Solder . . . . . . . . . 4-16

4-10 Soldering Tools and Consumables. . . . . . 4-16

SECTION 5 – MINIATURE REPAIR

5-1 Introduction. . . . . . . . . . . . . . . . . . . . 5-1

5-2 Removing and Replacing Parts. . . . . . . . 5-1

5-3 Special Soldering Techniques. . . . . . . . . 5-5

5-4 Printed Circuit andMicroelectronics Techniques . . . . . . . . . 5-65-4.1 Removal and Replacement

of Protective Coatings . . . . . . . . . 5-65-4.1.1 Tools and Materials. . . . . . . . . . 5-65-4.1.2 Removal of Protective Coating . . 5-65-4.1.3 Replacement of Protective

Coating . . . . . . . . . . . . . . . . . 5-95-4.2 Repair of Printed Circuit Boards . . 5-95-4.3 Void Repairs . . . . . . . . . . . . . . . 5-95-4.4 Lands Repairs . . . . . . . . . . . . . . 5-105-4.5 Peeled Conductors . . . . . . . . . . . 5-115-4.6 Loose Connector Tabs. . . . . . . . . 5-115-4.7 Broken Connector Tabs . . . . . . . . 5-125-4.8 Removal and Replacement

of Flat Packs . . . . . . . . . . . . . . . 5-135-4.8.1 Took and Materials. . . . . . . . . . 5-135-4.8.2 Removal and Replacement

of Soldering-In Flat Packs . . . . . 5-135-4.8.3 Removal and Replacement

of Welded-h Flat Packs. . . . . . . 5-165-4.9 Removal and Replacement

of DIPs . . . . . . . . . . . . . . . . . . . 5-165-4.9.1 Tools and Materials. . . . . . . . . . 5-175-4.9.2 Removal and Replacement

of DIPs on Boards WithConformal Coating. . . . . . . . . . 5-17

5-4.9.3 Removal and Replacementof DIPs on Boards WitboutConformaJ Coating. . . . . . . . . . 5-19

5-4.10 Removal and Replacementof TO-Type Packages . . . . . . . 5-19

Paragraph Page

5-4.10.1 Tools and Materials. . . . . . . . . 5-2054.10.2 Removal and Replacement

of Embedded TOS and TOSWithout Spacers. . . . . . . . . . . 5-20

5-4.10.3 Removal and Replacementof Flush-Mounted TOSand Plugged-In TOS WithSpacers. . . . . . . . . . . . . . . . . 5-21

SECTION 6 – MICROMINIATURE REPAIR

6-1 Introduction. . . . . . . . . . . . . . . . . . . . 6-1

6-2 Removing and ReplacingMicrominiature Parts . . . . . . . . . . . . . . 6-16-2.1 Reasons for Coating . . . . . . . . . . 6-16-2.2 Types of Coatings. . . . . . . . . . . . 6-76-2.3 Identification of Coating . . . . . . . 6-76-2.3.1 Relative Hardness of Coatings. . . 6-86-2.3.2 Transparency of Coatings. . . . . . 6-86-2.3.3 Thickness of Coatings . . . . . . . . 6-86-2.3.4 Volubility . . . . . . . . . . . . . . . . 6-96-2.3.5 Strippability of Coatings . . . . . . 6-96-2.3.6 Comparing Coating

Characteristics. . . . . . . . . . . . . 6-96-2.4 Coating Removal Methods , . . . . . 6-96-2.4.1 Solvent Method . . . . . . . . . . . . 6-96-2.4.2 Procedure for Solvent

Removal. . . . . . . . . . . . . . . . . 6-106-2.4.3 Stripping Method. . . . . . . . . . . 6-106-2.4.4 Thermal Parting Method . . . . . . 6-106-2.4.4.1 Thermal Parting Procedure . . . 6-106-2.4.5 Mechanical Abrasion Method . . . 6-116-2.4.5.1 Abrasive Removal of

Coatings. . . . . . . . . . . . . . . . 6-116-2.4.5.2 Abrasive Removal of Thick

Coatings. . . . . . . . . . . . . . . . 6-116-2.4.6 Hot Jet Method . . . . . . . . . . . . 6-126-2.4.6.1 Hot Jet Procedure for

Coating Removal. . . . . . . . . . 6-126-2.4.7 Non-Recommended Coating

Removal Methods. . . . . . . . . . . 6-126-2.4.8 Replacement of Conformal

Coating . . . . . . . . . . . . . . . . . 6-12

6-3 Repair of Printed Circuit Boards. . . . . . . 6-136-3.1 Repair of Multilayer PCBS . . . . . . 6-136-3.1.1 Repair of Damaged Holes

in Multilayer PCBS . . . . . . . . . . 6-13

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Paragraph Page

6-3.1.2 Repair of Internal Shorts. . . . . . . 6-146-3.1.2.1 Non Connector Area . . . . . . . . 6-146-3.1.2.2 Connector Area. . . . . . . . . . . . 6-14

6-4 Replating. . . . . . . . . . . . . . . . . . . . . . . 6-146-4.1 Introduction . . . . . . . . . . . . . . . . 6-146-4.2 Spot Plating. . . . . . . . . . . . . . . . . 6-156-4.3 Alternative Plating . . . . . . . . . . . . 6-156-4.3.1 Solder or Gold Plating. . . . . . . . . 6-156-4.3.2 Thin or Missing Gold

Plating. . . . . . . . . . . . . . . . . . . 6-15

6-5 Maintenance of Microstation . . . . . . . . . . 6-15

SECTION 7 – DIGITAL TROUBLESHOOTINGTECHNIQUES

7-1 Digital Testing Techniques . . . . . . . . . . . 7-17-1.1 Logic Clip . . . . . . . . . . . . . . . . . . 7-17-1.1.1 Theory of Operation of

Logic Clip. . . . . . . . . . . . . . . . . 7-17-1.2 Logic Probe. . . . . . . . . . . . . . . . . 7-17-1.2.1 Logic Probe Theory of

Operation. . . . . . . . . . . . . . . . . 7-17-1.2.2 Operational Checks. . . . . . . . . . . 7-47-1.2.3 Troubleshooting with a

Logic Probe. . . . . . . . . . . . . . . . 7-47-1.2.4 Logic Test Probe . . . . . . . . . . . . 7-57-1.2.4.1 Frequency Response . . . . . . . . 7-57-1.2.4.2 Minimum Pulse Width

Characteristics. . . . . . . . . . . . . 7-57-1.2.4.3 Circuit Loading. . . . . . . . . . . . 7-57-1.2.4.4 Power Versatility. . . . . . . . . . . 7-87-1.2.4.5 Construction of a Simple

Logic Probe . . . . . . . . . . . . . . 7-87-1.3 Logic Pulser. . . . . . . . . . . . . . . . . 7-107-1.3.1 Theory of Operation of

Logic Pulser . . . . . . . . . . . . . . . 7-117-1.3.2 Troubleshooting with a

Logic Pulser . . . . . . . . . . . . . . . 7-147-1.4 Current Tracer. . . . . . . . . . . . . . . 7-147-1.4.1 Theory of Operation of

Current Tracer. . . . . . . . . . . . . . 7-14

Paragraph Page

7-1.4.2 Troubleshooting with aCurrent Tracer. . . . . . . . . . . . . . 7-15

7-1.5 Logic Comparator. . . . . . . . . . . . . 7-187-1.6 Logic Analyzem . . . . . . . . . . . . . . 7-187-1.6.1 Software Diagnostic Techniques . . 7-187-1.6.2 Limitations. . . . . . . . . . . . . . . . 7-187-1.6.3 Data Acquisition . . . . . . . . . . . . 7-187-1.6.3.1 Data Channels. . . . . . . . . . . . . 7-187-1.6.3.2 Trace Specification . . . . . . . . . 7-19

7-1.6.4 Multiple-Occurence Trigger . . . . . 7-197-1.6.5 Data Storage . . . . . . . . . . . . . . . 7-197-1.6.6 Data Display . . . . . . . . . . . . . . . 7-197-1.6.6.1 List Display . . . . . . . . . . . . . . 7-197-1.6.6.2 Timing Diagrams . . . . . . . . . . . 7-197-1.6.6.3 System Overview. . . . . . . . . . . 7-197-1.6.7 Functional Measurements . . . . . . 7-197-1.6.8 Interaction with Other

Instruments. . . . . . . . . . . . . . . . 7-207-1.7 Minicomputers. . . . . . . . . . . . . . . 7-207-1.7.1 Asynchronous Operation. . . . . . . 7-217-1.7.2 Synchronous Operation. . . . . . . . 7-217-1.8 Setting Up the Logic Analyzer. . . . . 7-217-1.9 State Flow Analysis. . . . . . . . . . . . 7-217-1.9.1 Basic State Flow Measurement . . . 7-217-1.9.2 Graph Overview. . . . . . . . . . . . . 7-237-1.9.3 Measurements from a

Graph Mode . . . . . . . . . . . . . . . 7-257-1.9.4 Measurements on Selected

Types of Information . . . . . . . . . 7-257-1.9.5 Complex State Measurements

Using Sequential Triggers. . . . . . . 7-267-1.9.5.1 Tracing Multipath Programs. . . . 7-267-1.9.5.2 Tracing Nested Loops. . . . . . . . 7-277-1.9.6 Measuring Execution Time. . . . . . 7-287-1.9.7 Locating Intermittent Errors . . . . 7-317-1.10 Timing Analyzers . . . . . . . . . . . . 7-327-1.10.1 Analysis of Timing

Relationships ofControl Lines. . . . . . . . . . . . . . 7-32

7-1.10.2 Glitch Detection. . . . . . . . . . . . 7-357-1.10.3 Asynchronous Measurement

with a Logic State Analyzer . . . . 7-377-1.11 Summary. . . . . . . . . . . . . . . . . . 7-39

vi ORIGINAL

ILLUSTRATIONS NAVSEA SEOOO-00-E IM-160

LIST OF ILLUSTRATIONS

L

\

Figure Page

SECTION 2 – MAINTENANCE CONCEFI’S

2-1 Electronic Maintenance, Functional

Diagram. . . . . . . . . . . . . . . . . . . . . . . 2-12-2 Sample Maintenance Index Page. . . . . . . 2-42-3 Sample Maintenance Requirement Card. . 2-62-4 Sample Cycle Schedule. . . . . . . . . . . . . 2-92-5 Sample Quarterly Maintenance

Schedule . . . . . . . . . . . . . . . . . . . . . . 2-1o2-6 Sample Weekly Work Schedule. . . . . . . . 2-132-7 Sample PMS Feedback Form. . . . . . . . . 2-152-8 Sample Maintenance Data Form. . . . . . . 2-162-9 Sample Supplemental Report Form . . . . 2-182-10 Sample Work Supplement Card . . . . . . . 2-192-11 Sample Failed Parts/Components Card . . 2-202-12 Sample DD Form 1348. . . . . . . . . . . . . 2-202-13 Sample NAVSUP Form 1250. . . . . . . . . 2-22


3-1 Grease-Lubricated Ball Bearings . . . . . . . 3-83-2 Wick-Fed Ball Bearing . . . . . . . . . . . . . 3-103-3 Types of Soldering Irons and Tips. . . . . . 3-183-4 Soldering Guns. . . . . . . . . . . . . . . . . . 3-203-5 Punches. . . . . . . . . . . . . . . . . . . . . . . 3-223-6 Taps, Dies, and Reamers. . . . . . . . . . . . 3-233-7 Rotary Cutting Tools. . . . . . . . . . . . . . 3-243-8 Wire and Thread Gauges . . . . . . . . . . . . 3-253-9 Wire Stnppem. . . . . . . . . . . . . . . . . . . 3-253-10 Tube Puller . . . . . . . . . . . . . . . . . . . . 3-25

SECTION 4 – SOLDERING TECHNIQUES

4-14-2

4-3

4-4

4-5

4-6

4-74-84-9

TIN/LEAD Fusion Diagram. . . . . . . . . . 4-1Typical Types of Circuit BoardLead Terminations. . . . . . . . . . . . . . . . 4-8Turret Terminal Types and WireWrappings . . . . . . . . . . . . . . . . . . . . . 4-12Hook and Tab Terminal Typesand Wire Wrappings . . . . . . . . . . . . . . . 4-13Turret Terminal Soldering Using HeatBridge (Thermal Linkage) . . . . . . . . . . . 4-14Hook Terminal Soldering Using HeatBridge (Thermal Linkage) . . . . . . . . . . . 4-14Wire Splicing Methods . . . . . . . . . . . . . 4-15Electrical Connector Pin Solder Cup . . . . 4-17Voltage Control for Soldering Iron . . . . . 4-19

Figure Page


5-1 Miniature Tools. . . . . . . . . . . . . . . . . .5-2 Removal of Defective Parts. . . . . . . . . .5-3 Transistor Removal . . . . . . . . . . . . . . .5-4 Removal of a Multi-Lug Part . . . . . . . . .5-5 Printed Circuit Card Holder. . . . . . . . . .5-6 Void Repair Procedure. . . . . . . . . . . . .5-7 Lands Repair Procedure . . . . . . . . . . . .5-8 Peeled Conductor Repair . . . . . . . . . . .5-9 Peeled Connector Tab Repair/

Replacement . . . . . . . . . . . . . . . . . . .5-10 Removal and Replacement of Flat

Packs . . . . . . . . . . . . . . . . . . . . . . . .5-11 Flat Pack Lead Cutting Procedure. . . . . .5-12 Flow Soldering Technique. . . . . . . . . . .5-13 DIP Orientation for Repair . . . . . . . . . .5-14 DIP Lead and Coating Details . . . . . . . .5-15 DIP Package Puller. . . . . . . . . . . . . . . .5-16 TO Removal Procedure. . . . . . . . . . . . .5-17 Resoldering Iron With Cup-Type

Tiplet Adapter . . . . . . . . . . . . . . . . . .

5-25-35-45-55-85-1o5-115-12

5-14

5-155-165-175-185-185-195-21

5-22

SECTION 7 – DIGITAL TROUBLESHOOTINGTECHNIQUES

7-1 Logic Clip Block Diagram . . . . . . . . . . . 7-27-2 Decision Gate Network Flow Diagram. . . 7-37-3 Logic Level Lamp Indication with Probe

Input Voltage Levels . . . . . . . . . . . . . . 7-47-4 Logic Probe Schematic Diagram. . . . . . . 7-67-5 Logic Level Test Setup. . . . . . . . . . . . . 7-77-6 Positive Pulse Test Setup. . . . . . . . . . . . 7-77-7 Negative Pulse Test Setup. . . . . . . . . . . 7-87-8 Logic Threshold and Pulse Conditions. . . 7-97-9 Construction of a Simple Logic Probe . . . 7-97-10 Logic Probe Circuit . . . . . . . . . . . . . . . 7-107-11 Modified Logic Probe. . . . . . . . . . . . . . 7-117-12 Logic Pulser Timing Diagram. . . . . . . . . 7-127-13 Logic Pulser Schematic Diagrrun. . . . . . . 7-137-14 Logic Gate Testing. . . . . . . . . . . . . . . . 7-147-15 Testing for Shorts . . . . . . . . . . . . . . . . 7-147-16 Verifying Operation of Inverter-

Amplifiers . . . . . . . . . . . . . . . . . . . . . 7-157-17 Current Tracer Schematic Diagrsm . . . . . 7-167-18 Wire AND-node Fault. . . . . . . . . . . . . . 7-177-19 Gate-to-Gate Fault. . . . . . . . . . . . . . . . 7-177-20 Solder Bridge in Printed Circuit . . . . . . . 7-17

ORIGINAL vii

FRONT MATTER NAVSEA SEOOO-OO-EIM-160 1 LLUSTRATIONS

LIST OF ILLUSTRATIONS (Continued)

Figure Page Figure Page

7-21 MuItiple Gate Inputs . . . . . . . . . . . . . . 7-187-22 A Complex Program with

Braching Network . . . . . . . . . . . . . . . . 7-207-23 Timing Diagram . . . . . . . . . . . . . . . . . 7-227-24 Graph Mode Display . . . . . . . . . . . . . . 7-227-25 Example of an Asynchronous System . . . 7-237-26 Ex~ple of a Synchronous System. . . . . 7-237-27 Format Specification Menu. . . . . . . . . . 7-247-28 Trace Specification Menu . . . . . . . . . . . 7-247-29 Graphic Display of First 64 Addresses

of Startup Routine . . . . . . . . . . . . . . . 7-257-30 Graphic Display of Startup Routine

Displaying Discontinuity at Jump. . . . . . 7-277-31 Display of Output Routine . . . . . . . . . . 7-297-32 Example of Multipath . . . . . . . . . . . . . 7-297-33 Trace Specification of Path “A”. . . . . . . 7-307-34 Example of a Nested Loop . . . . . . . . . . 7-307-35 Trace Specification of Loop K. . . . . . . . 7-317-36 Example of Input/Output Service

Routine. . . . . . . . . . . . . . . . . . . . . . . 7-327-37 Trace Specification Menu for

Figure 7-34 . . . . . . . . . . . . . . . . . . . . 7-327-38 Format Specification Layout. . . . . . . . . 7-34

7-39 Trace Specification Menu toInitiate 060008 . . . . . . . . . . . . . . . . . . 7-35

7-40 Timing Diagram of Control LinesAfter Program Failure . . . . . . . . . . . . . 7-35

7-41 Timing Diagram of Control LinesBefore Program Failure. . . . . . . . . . . . . 7-35

7-42 Timing Diagram of Control Linewith Cursor . . . . . . . . . . . . . . . . . . . . 7-36

7-43 Timing Diagram of Control LinesTriggering on HLTRQ Line . . . . . . . . . . 7-36

7-44 Timing Diagram Displaying Assertionof AC-LO Flag . . . . . . . . . . . . . . . . . . 7-36

7-45 Trace Specification Menu Triggeredon End of Trace . . . . . . . . . . . . . . . . . 7-37

7-46 Format Specification Menu for BothState and Timing. . . . . . . . . . . . . . . . . 7-37

7-47 Timing Diagram Displaying a Glitchon Line 5. . . . . . . . . . . . . . . . . . . . . . 7-38

7-48 10x Magnification of Figure 7-47 . . . . . . 7-387-49 Format Specification to Assign

Labels. . . . . . . . . . . . . . . . . . . . . . . . 7-387-50 Trace Specification giving examples

of Activity at 60000 (8) . . . . . . . . . . . . 7-38

. . .Vlll

-.

ORIGINAL

---- .— . . . — ---. , ,V*. n ,., - , B b, . IVM v Ocfl OGUUV-UU-L I W1- I v u

LIST OF TABLES

L

L

Table Page

3-1

3-23-33-4

3-53-6

3-73-83-9

4-14-24-3

5-1

6-1

6-26-3


General Guide for UltrasonicCleaning . . . . . . . . . . . . . . . . . . . . . . 3-4Typical Air Filter Adhesives . . . . . . . . . 3-7Standard Navy Lubricants. . . . . . . . . . . 3-12Old and New SpecificationDesignations. . . . . . . . . . . . . . . . . . . . 3-14Manufacturer’s Designations . . . . . . . . . 3-15Lubricants Used in ElectronicsEquipments But Not Listed inMIL-L-17192D (Navy) (LubricationInformation of ElectronicEquipment) . . . . . . . . . . . . . . . . . . . . 3-15Solder Iron Tips . . . . . . . . . . . . . . . . . 3-17Pencil Iron Tips. . . . . . . . . . . . . . . . . . 3-17Soldering Gun Tips . . . . . . . . . . . . . . . 3-21

SECTION 4 – SOLDER TECHNIQUES

Recommended Soldering Tools . . . . . . . 4-18Consumable Supplies . . . . . . . . . . . . . . 4-18Voltage Control Parts List. . . . . . . . . . . 4-19


Tools and Materials for PartsRemovals. . . . . . . . . . . . . . . . . . . . . . 5-7

SECTION 6 – MICROMINIATURE REPAIR

Tools and Equipment MicrominiatureElectronic Repair . . . . . . . . . . . . . . . . 6-2Identification of Coatings . . . . . . . . . . . 6-8Coating Removal Methods. . . . . . . . . . . 6-9

Table Page

SECTION 7 – DIGITAL TROUBLESHOOTING

7-17-27-37-4

7-57-67-7

7-8

7-97-1o

7-11

7-127-137-14

TECHNIQUES

Typical Probe Specifications . . . . . . . . . 7-5Recommended Test Equipment . . . . . . . 7-8Typical Logic Pulser Specifications. . . . . 7-12Typical Voltage Ranges for CMOS,ECL, TTL Logic . . . . . . . . . . . . . . . . . 7-18List Display Data Format . . . . . . . . . . . 7-21Program Listing Sample Startup Routine . 7-26Trace List of First Twenty Statesof Program. . . . . . . . . . . . . . . . , . . . . 7-27Trace List Display Discontinuityin Program Execution. . . . . . . . . . . . . . 7-28Trace List Center Around Discontinuity . 7-28

Trace List Containing only WriteInstructions . . . . . . . . . . . . . . . . . . . . 7-28Trace List of All Write Instructions toOutput Buffer with Translation of Datato Alpha Numeric Code ., . . . . . . . . . . 7-29Trace List as Specified by Figure 7-33 . . . 7-30Trace List of a Nested hop . . . . . . . . . 7-31Trace List of Figure 7-44 withElapsed Time D;splayed . . . . . . . . . . . . 7-33

7-15 Trace List of Figu~ 7-44 withAbsolute Time Displayed . . . . . . . . . . . 7-33

7-16 Trace List of Reference . . . . . . . . . . . . 7-337-17 Trace List of Good Compare . . . . . . . . . 7-337-18 Trace List of Bad Compare . . . . . . . . . . 7-347-19 Contents of Pod-1 . . . . . . . . . . . . . . . . 7-347-20 Sequence of Program Execution. . . . . . . 7-357-21 Trace List Display of Power Fail

Trap Cells . . . . . . . . . . . . . . . . . . . . . 7-377-22 Control Line Labels. . . . . . . . . . . . . . . 7-387-23 Trace List Displaying Time

Measurements. . . . . . . . . . . . . . . . . . . 7-39

fin Ic Inl A I :..

GENERAL MAINTENANCE NAVSEA SEOOO-00-E IM-160 PREFACE

PREFACE

—

POLICY AND PURPOSE

The Electronics Installation and Mainte-nance Book (EIMB) was established as the medium forcollecting, publishing, and distributing, in one conven-ient source document, those subordinate maintenanceand repair policies, installation practices, and overallelectronic equipment and material-handling proceduresrequired to implement the major policies set forth inChapter 400 of the Naval Ships’ Technical Manual. Alldata contained within the EIMB derive their authorityfrom Chapter 400 of the Naval Ships’ Technical Man-ual, as established in accordance with Article 1201,U. S. Navy Regulations.

Since its inception the EIMB haa beenexpanded to include selected information of general in-terest to electronic installation and maintenance per-sonnel. These items are such as would generally be con-tained in texthooks, periodicals, or technical papers,and form (along with the information cited above) acomprehensive reference document. In application, theEIMB is to be used for information and guidance by allmilitary and civilian personnel involved in the installa-tion, maintenance, and repair of electronic equipmentunder cognizance, or technical control, of the NavalSea Systems Command (NAVSEA). The information,instructions, and procedures, in the EIMB supplementinstructions and data supplied in equipment technicalmanuals and other approved maintenance publications.

INFORMATION SOURCES

Periodic revisions are made to providethe best current data in the EIMB and keep abreast ofnew developments. In doing this, many source docu-ments are researched to obtain pertinent information.Some of these sources include the Electronics Informat-ion Bulletin (EIB), the NAVSEA Journal, electronicsand other textbooks, industry magazines and peri-odicals, and various military installation and mainte-nance-related publications.

ORGANIZATION

The EIMB is organized into a series ofhandbooks to afford maximum flexibility and ease inhandling. The handbooks are stocked and issued asseparate items so that individual handbooks may beobtained as needed.

The handbooks fall within two cate-gories: general information handbooks, and equipment-

“

oriented handbooka. The general information hand-books contain data which are of interest to all person-nel involved in installation and maintenance, regardlessof their equipment specialty. The titles of the variousgeneral information handbooks give an overall idea oftheir data content; the GeneraI Handbook includesmore complete descriptions of each handbook.

The equipment handbooks are devotedto information about particular classes of equipment.They include general test procedures, adjustments,general servicing information, and field change identi-fication data.

All handbooks of the series are listedbelow with their NAVSEA numbers.

HANDBOOK TITLE

EIMB General

NAVSEA NUMBER

Information Handbooks

General SEOOO-OO-EIM-1OO. Installation Standards SEOOO-OO-EIM-11OElectronic Circuits SEOOO-00-EIM-120Test Methods& Practices SEOOO-OO-EIM-130

Reference Data SEOOO-OO-EIM-140EMI Reduction SEOOO-OO-EIM-150

General Maintenance SEOOO-OO-EIM-160

EIMB Equipment-Oriented Handbooks

Communications SEOOO-OO-EIM-O1ORadar SEOOO-OO-EIM-020Sonar SEOOO-OO-EIM-030Test Equipment SEOOO-OO-EIM-040Countermeasures SEOOO-OO-EIM-060

DISTRIBUTION

Initial Set: An “AF>’ Restriction Codehas been assigned to NAVSEA SEOOO-OO-EIM-OOOcontrol the over-requisitioning of the EIMB Series.Fleet and shore activities requiring an initial set of theEIMB Series (13 handbooks with all changes andheavy-duty bindera) should submit their requisition(DD Form 1348 with written justification) throughtheir Supply Officer or area, for issue approval to:

CommanderNaval Sea Systems CommandNAVSEA 05L31Washington, D.C. 20362

nm ICIrd A I

L

PREFACE NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

REFA

.

\

P

Use the following data on the DD-1348,Block A - 288 NAVPUBFORMCENPHILAStock No. - 0967 -LP-OOO-OOO0Unit of Issue - SEFund -00

All other blocks are to be filled in as normally doneby the requisitioner when ordering publications.

Changes and Revisions: The EIMB iscontinuously being updated. For efficiency thesechanges and revisions are automatically distributed tousing activities who are on the Automatic Distrib-ution List for the EIMB.

Requests and/or changes to the EIMBAutomatic Distribution List and any problems inrequisitioning should be directed to:


Individual Handbooks: To order indi-vidual handbooks and changes, use the stock numbers

ORIGINAL xi/(xi

CE

listed in the Box Score on page i. Using the stocknumber for the “BASIC” provides the handbook(with vinyl cover) and all appliv

SUGGESTIONS/CORRECTIONS

NAVSEA recognizes that users of theEIMB will have occasion to offer corrections or sug-gestions. To encourage more active participation, apre-addressed comment sheet is provided in the backof each handbook change. Complete informationshould be given when preparing suggestions. Sug-gesters are encourages to include their names andaddresses so that clarifying correspondence can be in-itiated when necessary. Such correspondence will beby letter directly to the individual concerned.

If a comment sheet is not available, orif correspondence is lengthy, corrections or sugges-tions should be directed to the following:


i Blank)

------ - . -- - ... —-.. . ----. . . . . — . . . ----- .-— . . . . — - -. - .------,- --- . ---- . . . . . . . . . -. . . . . . . - . . . . . .

SECTION 1

INTRODUCTION

,

1-1 PURPOSE

The purpose of the General Mainte-nance Handbook, NAVSHIPS SEOOO-OO-EIM-160, isto provide Naval personnel with an informative andcomprehensive maintenance reference. This handbookcontains general maintenance data that pertains to allelectronic equipments and it can be used to supple-ment information contained in equipment technicalmanuals. The satisfactory performance of modemelectronic equipment depends to a great extent uponthe maintenance procedures employed by the elec-tronics technician. It further depends upon the skill-ful application of these procedures by the technician.Continued satisfactory performance is dependent uponthe work done by the men who inspect, repair, andmaintain electronic equipment. The objectives of theGeneral Maintenance Handbook are to aid in themaintenance effort by:

1. Preparing and assembling, in onehandbook, the approved procedures and concepts tobe employed in the maintenance of all electronicequipment.

2. Standardizing these procedures andconcepts which, when used, will provide uniform andsatisfactory electronic maintenance.

3 . I n d o c t r i n a t i n g cI1 personnelengaged in maintenance with the importance of goodworkmanship.

4. Making all personnel involved inelectronic maintenance aware of the importance ofgood maintenance techniques.

5. Preventing personnel injury andequipment damage by emphasizing safety precautionsand by prohibiting unsafe maintenance practices.

1-2 SCOPE

Information for the General Mainte-nance Handbook has been collected from other EIMBhandbooks, the EIB, the NAVSHIPS Technical News,and many other pertinent sources, both militaryand commercial. The General Maintenance Handbookwill be useful as a convenient reference book forthree general categories of maintenance personnel:

ORIGINAL 1-1

1-2.1 EXPERIENCED TECHNICIANThe experienced technician has no

great difficulty in coping with maintenance pro-blems because of previous experience and well devel-oped maintenance skills. This person will use thehandbook as reference or review material. He will in-crease his knowledge of electronics maintenance asnew concepts and procedures are added to this text.

1-2.2 TECHNICIAN OUT-OF-SCHOOLThis category of technician is repre-

sentative of the individual who has completed Navytraining courses, but has limited experience with thefleet. His experience will probably be limited toequipments covered in training courses and to equip-ments he has encountered in his brief tour of dutywith the fleet. Consequently, this handbook will proveextremely valuable to him, especially as new equip-ments are confronted. The maintenance concepts inthis handbook will help familiarize him with the newtechniques involved in maintaining modern equip-ments.

1-2.3 TRAINEEThe trainee willl find the information

contained in the handbook to be useful as a referencewhile in training. Later, he will find that it serves asa source of review as well as reference. As a training aid,the individurd sections might be recommended forsuggested reading. Information contained in this hand-book is of lasting interest to all Naval personnelengaged in the maintenance of electronic equipment.

1-3 ORGANIZATION

Information in the General MaintenanceHandbook, NAVSEA SEOOO-OO-EIM-160, is presentedin seven sections:

Section 1- INTRODUCTION

This section explains the purpose,scope, and organization of the General Maintenance

Handbook. It also describes the relationship of thishandbook to other handbooks of the EIMB series.

INTRODUCTION NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

Section 2- MAINTENANCE CONCEPTS

This section presents the basic conceptsto the technician. These concepts are the foundation ofgood electronic maintenance. Preventive maintenanceprograms (POMSEE and PMS) are explained and theprocedures required for carrying out these programs arecovered. Responsibilities of the operator and tech-nician in carrying out the preventive maintenance pro-gram are defined. Troubleshooting and failure analysisare discussed. Types and classes of alterations, fieldchanges, and the procedures to follow after accomplish-ment of each are also covered in detail in this section.

Section 3- ROUTINE MAINTENANCEAND MAINTENANCE AIDS

This section reviews routine mainte-nance procedures such as cleaning; inspection; lubrica-tion; use of maintenance aids, such as soldering toolsand special hand tools; and soldering and splicingtechniques. Emphasis is placed on the importance ofthese procedures in hopes of making the technicianmore aware of their value. The importance of safety,not only to prevent injury to the technician, but toprolong the life of electronic equipment as well, arealso required. References are made to publicationsthat cover personnel safety and equipment operationand maintenance safety procedures.

Section 4- SOLDERING TECHNIQUES

Because of the complexity of today’smodem electronic systems and the lack of

1-2

documentation on the subject, an attempt has beenmade to acquaint the technician with some of thesystem test equipment that has been, and is being,designed to test these modem systems. When these newmeans of testing are not available, the technician is toldhow to use the resources at his disposal to cope withsystem maintenance problems.

Section 5- MINIATURE REPAIR

This section gives a practicaJ approachto the problem of maintaining equipments. Mainte-nance information such as testing, troubleshooting, re-pair of subassemblies, modular components, andprinted circuit boards is included in this section.

Section 6- MICROMINIATURE REPAIR

This section is broken into a numberof subsections, each of which deals with one typeof component and its associated maintenance pecu-liarities. Information such as special tests, removal andreplacement, and inspection is presented in detailfor each of the major components discussed in thissection.

Section 7- DIGITAL TROUBLESHOOTINGTECHNIQUES

This section provides practical tech-niques of digital troubleshooting with logic clips, logicprobes, logic pulsers, current tracers, logic comparatorsand logic analyzers. State Flow analysis techniques arealso covered in this section.

ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 MAINTENANCE CONCEPTS

SECTION 2

MAINTENANCE CONCEPTS

2-1 INTRODUCTION

In general, the concept of mainte-nance is that of work done to correct, prevent, orreduce failure and damage to equipment. Mainte-nance of Navy electronic equipment is divided intotwo main categories: preventive maintenance, andcorrective maintenance. Preventive (routine)maintenance consists of checks to determine ifequipment is functioning properly, visual inspectionsfor damage, and lubrication. Corrective maintenance

SHIPBOA

MAINTEN

E L E C T R

EOUIPME

\CORRECTIVE

MAINTENANCE

\ \TESTINA

\

TEST IN G- FUNCTION

TECHNIQUES AND DIvISIOPRACTICES

(TROUBLE SHOOTING) OF TEST

\ \

Figure 2-1. Electronic Mainten

finflr=finl n I -64

is the isolation of trouble, the replacement of defectivecomponents, and the realignment and readjustment ofequipment to restore it to a satisfactory operatinglevel. See figure 2-1.

2-2 PREVENTIVE MAINTENANCEPROGRAMS

An electronics preventive maintenanceprogram consists of a schedule of inspections, tests,and routine maintenance procedures and a system of

\

RD

ANCE <O N IC

N T

\PREVENTIVE OR

SCI+EDUL E D

MAINTENANCE

G \ A \

\INSPECTIONS

\ \

\

AL

NS CHECKS

ING

ance, Functional Diagram

MAINTENANCE CONCEPTS NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

-.

checkoff lists to ensure that the schedule is carriedout. The administration of such a program aboard shiprequires that the preventive maintenance needs ofevery equipment be recognized, planned for, accom-plished, and recorded. The Planned Maintenance Sub-system (PMS) has been developed to accomplish thesetasks. The Performance Operation and MaintenanceSystems for Electronic Equipment (POMSEE) is stillcurrent for selected equipments; however, it is currentlyimplemented only on a case basis. These programs donot provide a means for technicians to report mainte.nance problems. Such a system employing automaticdata processing was then developed. This system,the Maintenance Data System (MDS), complements thePMS to form the basic Maintenance and MaterialManagement (3-M) System. Each of these currentmaintenance programs (POMSEE, PMS, and 3-M)are discussed subsequently.

2-2.1 POMSEE PROGRAMThe POMSEE program is designed to

help operational and maintenance personnel determineand maintain proper performance of electronic equip-ment. It is implemented on a case basis by acquisitionmanagers. The fundamental elements of POMSEE arethe Reference Standards Tests, Reference StandardsSummary Sheets, and Performance Standards Sheets.The Reference Standards Tests and ReferenceStandards Summary Sheets comprise the ReferenceStandards Book. The scheduled tests, however, aresuperseded when the PMS is implemented. The re-quirements for establishing the Reference StandardTests for electronic equipment after installation, andfor using these test procedures as a basis for equipmentcheck-out after overhaul or restoration, remain ineffect. A preliminary copy of the Reference StandardsBook is normally packed with each new electronicequipment. Upon its receipt, maintenance personnelshould immediately perform the tests listed in theReference Standards Tests and forward the resultsrecorded on the Reference Standard Summary Sheetsto NAVSEA for review. Finrd copies or changes arethen published after NAVSEA evaluates the ReferenceStandards Summary Sheets. POMSEE is a test docu-ment for equipment check-out after its installation orre-installation aboard ship, and after steps have twentaken to ensure that the equipment is properlyinstalled and operating satisfactorily. It does not elimi-nate the necessity for making adjustments, alignments,checks, or other installation procedures described inthe technical manual which are necessary to obtain

2-2

satisfactory operation. Before establishing thereference standards, the equipment must be completelychecked out by qualified technical personnel to ensureoptimum equipment operation. The qualified tech-nical personnel should have received training in opera-tion and maintenance of the equipment and have suffi-cient skill to tune, align, and peak the equipment untilit is performing as near design characteristics as pos-sible. While there is no objection in having the instal-ling activity perform operational tests in the shopprior to installation, NAVSEA requires that thePOMSEE measurements be conducted on board ship,operating off ship’s power. Shop tests will not disclosethe effects of poor installation, wiring errors, noisepickup, instability in ship’s power generating source,self-generated and receiving interference, or therough handling effects in transportation from shop toship.2-2.1.1 Reference Standards Tests

The Reference Standards Tests consistof a series of measurements made initially when theequipment is operating at peak performance. Thesemeasurements, containing upper and lower limits, pro-vide maintenance personnel with standards againstwhich subsequent measurements may be compared.The tests are scheduled on a routine basis such asdaily, weekly, and monthly. Daily tests are designed sothat they can be performed in less than 10 minuteson a single-unit set. These tests are usually performedby the operator on watch and they consist mainly of aperformance check using the equipment modes andfeatures, and built-in test equipment. Weekly tests aredesigned to monitor an equipment function wherethere is a definite likelihood that the interpretationof test results will reveal potential trouble. Monthlyand quarterly tests consist of measurements that can-not normally be performed when the ship is under-way. Examples typical of this test are: sonar beampattern tests, sonar transducer maintenance, andcleaning and lubricating antennas. In some instances,unscheduled tests are provided. These tests are notdesigned to detect impending failure but are performedupon completion of repair for check out.2-2.1.2 Reference Standards

Summary SheetsThe Reference Standards Summary

Sheets basically provide spaces for recordingmeasurements and the initials of the person performingthe tests. The tests used are those in the ReferenceStandards Tests. Two identical Reference StandardsSummary Sheets precede the front matter of a newly

ORIGINAL


issued Reference Standards Book. After the sheets arefilled in, one is retained in the book and the second issubmitted to NAVSEA for evaluation.2-2.1.3 Performance Standards Sheets

The Performance Standards Sheets listthe operational characteristics of an equipment orsystem. The characteristics given include such para-meters as meter readings, sensitivi@ values, outputpower, standing wave ratios, and all other measurableparameters that indicate the operational condition ofthe equipment. Performance Standards Sheets areused by maintenance personnel to determine theoverall operation of an equipment by comparing itsdata with the test results recorded in the ReferenceStandards Book. This sheet is usually the first page ina newly issued Reference Standards Book. As part ofthe POMSEE program, this sheet should be removedfrom the Reference Standards Book and placed in abinder titled, “Electronic Equipment PerformanceStandard Sheets,” NAVSEA 93000.

2-2.2 MAINTENANCE AND MATERIALMANAGEMENT SYSTEMThe Maintenance and Material Manage-

ment (3-M) System is an integrated managementsystem which, when fully implemented and properlyused, provides for orderly scheduling and accomplish-ment of maintenance and for reporting and dissemi-nating significant maintenance related information.It is composed of two principle subsystems: thePlanned Maintenance System (PMS), and theMaintenance Data System (MDS). Together, PMS andMDS form the nucleus of a shipboard maintenance pro-gram which can contribute significantly toward achiev-ing improved fleet readiness with reduced expenditureof resources.2-2.2.1 Planned Maintenance System

The Planned Maintenance System (PMS)pertains to the planning, scheduling, and manage-ment of resources (men, material, and time) to performthose actions which contribute to the uninterruptedfunctioning of equipment within its design charac-teristics. It defines uniform maintenance standards,based on engineering experience, and prescribes sim-plified procedures and management techniques forthe accomplishment of maintenance. The increasingcomplexity and quantity of equipment required forthe operation of the modern Navy has necessitatedthe continuous updating of maintenance proceduresand the refinement of maintenance management

ORIGINAL 2-3

organization at all levels. These improved proceduresare necessary for the assurance of equipment readiness,the key to operational readiness. For this reason it isof utmost importance that all maintenance personnelbe familiar with the proper use of the PMS documentsand schedules for implementing and accomplishingplanned maintenance. OPNAVINST 4790,4 describesthe detailed operation of PMS. The following para-graphs summarize shipboard operation.2-2.2.1.1 Maintenance Index Page

The Maintenance Index Page (MIP),OPNAV Form 4700-3, is the basic reference document inthe PMS. See Figure 2-2. It catalogues the maintenancerequirements, skill levels considered qualified toperform the maintenance requirements, referencedocuments, and other reference data for all equip-ments listed in the Master manuaf. Each MIP containsa list for one set of Maintenance Requirement Cards.Specifically, the information listed is as follows:

1. The system, sub-system, or compo-nent, by noun name, AN Nomenclature, Mark, Mod, etc.

2. Reference Publications pertainingto the specific system, sub-system or component.

3. The date of preparation of theMIP (month and year).

4 . T h e System Command MRCControl Number to control library issue and identifyspecific MRCS as applicable to a certain MIP.

5. A brief description of each main-tenance requirement.

6 . The per iodic i ty code of eachmaintenance requirement listed on the MIP.

7. The recommended skill level/sconsidered qualified to perform the maintenancerequirements.

8. The average time required for eachskill level listed to perform the maintenance require-ments as listed. (This does not include “make ready”and “put away” time.)

9. Any related maintenance actionsto be scheduled for simultaneous accomplishment.

10. Notations included as ManagementAids when such information is available and neededfor selective scheduling of a specific requirement.MIPs are a ready reference to be used in conjunctionwith the planning and scheduling of PMS. Each MIPindexes one complete set of MFtCs which are applica-ble to a component or system.

11. A letter and a number indicatingthe Maintenance Group and the equipment concerned,


,TEM< SU8SYSTEM, OR cOMPONENT REFERENCE PW. LICAT90NS ..7,~put Output lhta Display Group AN/IJYA-5(xN-lW) NAVSHI= Nov 1970

0967-306-40100967-306-4020

S“, COM .“..,, .10

.0.7”0. NOu.,. ,... .,, . ’ . . \ . E.AC. , m:~,t” . , .,.‘“’LL . 0 ” . ,~*~ “M’.;:::”

*ANCE

864376 Check nutput voltage of Power Supplles w ET3 .5 None

864377 Cbeck memory drive current M ET3 .5 None

. . . . . . . . ,., ..- . . . . ,“, .! ,,, , 0 . 4 ..!, C O N T . . . . . . . . .,”,..””.. ,m. c, . . . . ,-, . ,. . . . . 470, 3 !“, . ), /,0

Figure 2-2. Ssmple Maintenance Index Page

2-4 ORIGINAL

--. .-— . . - - - .- .——. . - —------ . . .- . . . . ---- . -.. —---- ... - . . . . . - ---- . . -. --- -. --- . . . . . . --- . .“. - . . . . . . . . . . . . . . - . . . . . . . -- . -

for example, F-1, (F) indicates the Fireroom mainte-nance group and the (1) indicates Boilers.2-2.2.1.2 Maintenance Requirement Card

The Maintenance Requirement Card(MRC), OPNAV Form 4700-1, is a 5 x 8-inch cardwhich defines a specific preventive maintenance task interms of step-by-step procedures. See Figure 2-3. Itprovides maintenance personnel with detailed guidancefor performa]ice of each specific PMS requirement. TheMRC contains the following information and in-structions:

1. The identification of the System,Subsystem, or Component involved in the maintenanceaction.

2. The MRC Code assigned to the card.This code is in two parts. The first part is the EquipmentCode adapted from the first portion of the numberidentifying the MIP for that card set in the Depart-mental and Work Center PMS Manuals. The secondpart identifies the periodicity for the maintenanceaction, using a letter code for ~petitive time ele-ment as follows:

D -w -M -

Q-s-A -c -R -

DailyWeeklyMonthlyQuarterlySemi-annualAnnualOverhaul CycleSituation Requirement(100 hr., prefiring, priorto getting underway, etc.)

The periodicity code also includes anumber for specific identity when more than oneMRC of the same penodicity exists in the same MRCset. When two or more MRCS in the same set areprepared for the same periodicity, but for separate,distinct job requirements, the cards will be numberedconsecutively e.g., “D-1”, “D-2”, or “M-l”, “M-2”,etc.

3. When a single maintenance require-ment has need for more than one penodicity they willbe numbered as “Q-lR”, “M-lR”, “M-2 R”, etc.;the “R;’ in the case meaning “related,” indicates asituation that is defined in an accompanying note.Related maintenance requirements are maintenanceactions described on other MRCS within the sameset which are most efficiently accomplished whenthey are done prior to, in conjunction with, or after atask described on the basic MRC. For example, if

ORIGINAL 2-5

the equipment is opened for a maintenance action,that MRC may list and identify other MRCS whichalso require equipment opening and, therefore, canmost logically and appropriately be accomplished atthis same time. The intent of related maintenance isto take advantage of work effort and to avoid repe-titious maintenance steps. If no related maintenanceexists, the word “Non” will appear in this block.

4. Maintenance Requirement Descrip-tion is a brief description of the PMS action to beperformed.

5. Rate is the recommended skilllevel, identified by rate or Navy Enlisted ClassificationCode (NEC), designated to perform the describedmaintenance action. This information is providedas a management aid for workload assignment.

6. The average manhours required toaccomplish the PMS task by each rate. The totalmanhours and total elapsed time are also listed.These times are expressed to the nearest tenth of anhour. “Make ready” and “put away” times are notincluded.

7. Safety Precautions direct attentionto potential hazards to personnel or equipment whileperforming maintenance tasks. “Observe StandardSafety Precautions” is required in this block on everyMRC. These are two specific categories of additionalprecautionary conditions. They are:

WARNING

Operating procedures, prac-tices, etc., which may resultin personnel injury or lossof life if not correct lyfollowed.

CAUTION

Operating procedures, prac-tices, etc., which i f no tstrictly observed, may resultin damage to the equip-ment.

WARNINGS and CAUTIONS are re-peated immediately before the appropriate proceduralstep.

8. Safety of Ship. An MRC that hasbeen identified on the MIP as a Safety of Ship Itemwill have “SAFETY OF SHIP” stamped in large outlineletters across the face of the MRC and in such a

MAINTENANCE CONCEPTS NAVSEA SEOOO-OO-EIM-160

iifif”output Data Display CoM’oNEN ‘;roup AN/UYA-5 (XN-l)(V) Memory

UOS” STEM RELATEO WA, NT EN A?i CE

NomAI NT E?4. NCE “EQ”, ~E9.!E. T OESCR, P7,0N

Check memory drive current

.FETY PREC6UT+OWS

OscilloscopeTuning ‘rool

Current Probe for oscilloscope

GENERAL MAINTENANCE

IRc coo.

E17 M-1

T

RATES IA, H

ET3 0.5

,0,, . )4,”

0 . 5

ELAPSED TIME

0 . 5

1. Check Memory Drive Current

a.

b.c.

Place ON-LINE/OFF-LINE switch on maintenance panelto the off-line position.Set data toggles on maintenar.we panel to the 1 position.Connect current prohe in turn to the followtng points:(1) J17-10(2) J17-20(3) J18-10(4) J18-20(5) J19-10(6) J19-20

Oscilloscope should indicate O. 5V +0. IV

,CAT, ON DATE

5 Nov 1970MAINTENANCE REQUIREMENT CARD (MRC)OPNAV 4700.1 (Cl (RE V . !!/6#1

Figure 2-3. Sample Maintenance Requirement Card

2-6 ORIGINAL


manner to avoid interference with other printing onthe MRC. If Safety of Ship Items is included on anassociated Equipment Guide List, the MRC has both“SAFETY OF SHIP” and “EQUIPMENT GUIDE LIST”stamped on the face of card. Every effort has beenmade to indicate hazards in the safety precautionsblock and at appropriate steps in the proceduresblock; however, common sense, through safetyindoctrination and training of pemonnel maintain-ing and operating shipboard equipments, is stillrequired.

9. A list of specific tools, parts andmaterials required to properly perform the mainte-nance action is given.

10. Detailed step-by-step procedures tobe followed to accomplish maintenance actions aregiven. In some instances, cards will contain blankswhich must be completed by ship’s personnel in orderto supply the data (e.g., limiting speeds, tolerances,and pressures) necessary for the proper executionof the work specified. These data readings will varyfrom ship-to-ship.

11. The System Command MRCControl Number in the lower right side is a LibraryIdentification Code. This number must be referencedalong with MRC codes in all correspondence per-taining to specific MRCS.

12. A space is also provided for re-cording the location of a specific equipment aboardindividual installation, or for alerting maintenancepersonnel to the existence of EGLs.

13. In most cases, the contents of theMRC is unclassified even though it may be applicableto classified equipment. In cases where classificationof an individual MRC is required due to content,the following entry is found in the “Procedure”block: “Maintenance Procedure with this requirementis CLASSIFIED. MRC is stowed in 9,

(Ship will fill in the blank.) The completed MRC isprinted on pink stock with the classification printed attop and bottom of each printed side and shall behandled in accordance with OPNAVINST 5510-1 series(Security Manual for Classification Information).

14. The date on the card is the monthand year when the MRC was prepared.

15. The MRC cards are to be used asfollows:

a. A complete working group ofMRCS are to be located, in the holder provided, inthe work center area.

b. Maintenance personnel are to re-move the assigned MRCS from the Work Center

ORIGINAL 2 - 7

card container, obtain the required tools, parts, andmaterials listed on MRC, and perform the mainte-nance action as stated on MRC, observing all safetyprecautions.

c. When compIeted, maintenancepersonnel should then correct and/or report anydeficiencies discovered during the performance of themaintenance action. Report the completion of themaintenance action to the Work center Supervisor,who will update the Weekly Schedule.

d. The MRCS should then be re-turned to the container after the job has beencompleted.2-2.2.1,3 Equipment Guide List

The Equipment Guide List (EGL)is a 5- x 8- inch card that accompanies specific MRCSto list identical-type equipment to which preventivemaintenance task is to be performed. Identical-typeequipments, such as radar repeatm, power supplies,etc., are listed to show their quantity and location.

For examPle, a particular ship may have eightAN/SPA-4A Radar Repeaters, and each repeaterrequires the accomplishment of the same preventivemaintenance task. The EGL is actually an extensionof the Cycle and Weekly Schedules. When EGLsare required, a Guide List Index (GLI) is also preparedlisting each EGL along with its controlling MRC.The index is included at the end of the List ofEffective Pages in the PMS Manual.2-2.2.1.4 Cycle Schedule

The Cycle Schedule (OPNAV Form4700-4), shown in figure 2-4, is a visurd display of theplanned maintenance requirements that are to beperformed by shipboard personnel between majoroverhauls of the ship. “Between overhauls” is definedas “the time between a departure after overhaul andthrough the completion of the next major overhaul.”Most PMS requirements listed on the CycleSchedule are within the capability of the ship’s force.Occasions may arise where specicd test equipment,special tools, or outside assistance will be requiredin order to accomplish the required maintenance. TheCycle Schedule contains the name and hull numberof ship involved, the work center concerned, theeffective date of the schedule, the listings of the MIPsand their related systems, subsystems and componentsfor which the PMS requirements are to be scheduled.It also contains the schedules of the Semiannual,Annual, Cycle, and Situation Requirements. Cyclerequirements axe divided into “Quarters after Overhaul”for listing the Quarterly requirements, and Monthlyrequirements which have been scheduled in each


quarter. Care and attention must be devoted to thepreparation of the Cycle Schedule as it has a directinfluence on the subsequent effectiveness of the longrange PMS scheduling by maintenance personnel.The procedure for filling out the Cycle Schedule isas follows:

1. Type in the ship’s name and hullnumber in the upper left block and enter the date ofpreparation in the upper right corner. When a newcycle schedule is prepared, the old schedule must befiled with its applicable quarterly schedule.

2. Type in the Maintenance GroupBlock, i.e., Raclio ITs, Radar ET. Indicate sheetnumber (e.g., 1 of 3, 2 of 3, 3 of 3) when more thanone schedule is required.

3. Starting with the first MIP in theWork Center Manual, list the Equipment Code in thefirst column titled “Equip Page” (that is, E-I,F-l,EL-4, A-l). When more than one of the same equip-ment is located in the same Work Center, each mustbe entered as a separate line item. For example, twopower supplies are located in the same space; PS-1will be entered twice, on separate lines.

4. From the MIP in the columntitled “Component, “ list the noun name or AN nomen-clature of each component. If more than one of thesame type equipment is located in the same WorkCenter, each will be identified separately using thestandard shipboard numbering system (i.e., Radio#l, Radio #2, ECM ##1, ECM #2, and including equip-ment serial numbers). When a large number of similarequipments such as radar, power supplies, radarrepeaters, etc., are to, be maintained in accordancewith the same MRC, it is advantageous to use theEquipment Guide List method of accountability.The last line of the Cycle Schedule should be leftblank so that space will be available on the matchingQuarterly Schedule for the entry of ship’s operationalschedule, including space to make corrections with-out completely removing the previous operationalschedule.

5. From the MIP, list each Mainte-nance Requirement for Monthly (M), Quarterly (Q),and Situation Requirement (R) in the column headed“Each Quarter.” Situation Requirement requirementsare listed here only as a reminder and will not bescheduled on a calendar basis. Daily (D) and Weekly(W) requirements are scheduled only on the weeklySchedule and are not listed on the Cycle Schedule.Calendar requirement which may be modified by asituation, such as A-2R, will appear in appropriate“Quarter After Overhaul” column. Pay particular

2-8

attention to the “Related Maintenance” columnof the MIP. If any Semi-annual (S), Annual (A) orCycle (C) requirements are related, they shall be sched-uled in the same “Quarter After Overhaul” column.

6. From the MIP, list each Semi-annual (S) maintenance requirement in one of the fourcolumns titled “Quarter After Overhaul,” then list thesame requirement to occur six months later. Forexample, an S-1 requirement scheduled to occur in the1,5 and 9 quarters shall also be scheduled to occur inthe 3, 7 and 11 quarters. Requirements in these fourcolumns should be staggered to ensure an even distribu-tion of workload.

7. From the MIP, list each Annual(A) maintenance requirement in one of the fourcolumns titled “Quarter After Overhaul.”

8. From the MIP, list each Cycle (C)maintenance requirement, reviewing each to determineif a specific quarter after overhaul is indicated on theMIP. Ensure that all Cycle requirement have anappropriate quarter after overhaul indicated in paren-thesis after each entry on the cycle schedule. As anexample, C-1 (6) is a Cycle maintenance requirementscheduled to be accomplished in the 6th quarter afteroverhaul.

9. Cycle Schedules for ships with over-haul cycles extending beyond 12 quarters will be pre-pared for the entire overhaul cycle indicating 13, 14,etc., as necessary. Sbips with overhaul cycles less than12 quarters will schedule “Cycle Requirements” withinthe specified overhaul time frame. Ships encounteringdelays in entering overhaul shall extend their cyclescheduled by the addition of appropriate quarternumbers in the “Quarter After Overhaul” block.(Ensure cycle requirements required prior to enteringoverhaul are reviewed and rescheduled as necessary.)

10. The completed “Cycle Schedule”sball be signed by the Department Head over the words“Scheduled As Indicated.”2-2.2.1.5 Quarterly Schedule

The Quarterly Schedule (OPNAV form4700-5), shown in Figure 2-5, is a visual display of theship’s tentative operational employment schedule inconjunction with the !’MS requirements to be perform-ed during a three-montb period. This schedule is adirective issued by the Department Head and as suchmay be changed only by him or his authority. It isupdated weekly and provides a ready shipboardreference to the current status of PMS for each WorkCenter. The schedule provides space for entering“Work Centers, Year, Quarter After Overhaul,” andthe current months covered. Space must be reserved

ORIGINAL

GENERAL MAINTENANCE

L

E l

E 2

L

L

E 3

E 4— -

NAVSEA SEOOO-OO-EIM-160 MAINTENANCE CONCEPTS

USS W o r c e s t e r,, ,. CL 144

MA I .,11 N A N ( I ,,:, ,,, ,

;omputer E T( ,~.1, ( r, 1. :, i

AN/uYA5(xN-1) (’

AN/uYA6(xN-1)(’

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RO-367(XN-1) /U1

+-

— .— —

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—.

ti””---”-”--”-

D a n i e l B u c k l e y, \ I ! I ,1 i 1 A > I P, [) I C A T t ).

UJAK T Lk AF T Lk C Vt kll AuL

Al

——

— . —

-=H-

1 1 / 7 0

LACtl

U(JAk T L R

Ml QI -

M l Q1

M l Q 1

M l QI

CYCLE SCHEDULE OPNAV FORM 4700-4 (3-68) W. 0107. 7(56. ,;00 , C. 2521!

*U. S. G O VE RN MENT PRINTING OFFICE : 1968 -346-B86/A.110

Figure 2-4. Sample Cycle Schedule

2-9


“A’ N’C”KC ‘w’ Computer Room Y[AR 1971 WARTER AFTER OVER?4Uk 2 Daniel Buckley

C+47M Jan mm Feb mm Mar4 11 18 25

Jan1

MI, Q1 Ml Ml

Al, M1, Q1 Ml Ml

MI, Q1 Ml Ml

Ml QI Ml Ml

UPK UPK ASW ASW ASW UPK UPK I UPK UPK UPK UPK UPK UPKQUARTERLY MA I IITENANCE SCHEDULE OMbV FORM U700-5 (’+64) ,. ..,,,

Figure 2-5. Sample Quarterly Maintenance Schedule

. . 2 - 1 . 0 . . QRIG I.NAL

------ . . . . . . . . . . . . . ---- . . .-— -— . . .--, .-0 . . .- !. . - . . . , -, . - , - - - lun voLm OLUUU-UU-G1 Ivl - IUU WIJ+I IU I L IWMNb C ~uw~cr I a

on the schedule for entering tentative ship’s employ-ment schedule. Thirteen columns, one for each week inthe quarter, are available to enable scheduling of main-tenance requirements on a weekly basis throughoutthe quarter. The procedure for filling out the QuarterlySchedule is given below.

1. Enter the name of Work Centerconcerned in the space provided on the schedule.

2. Enter the corresponding sheetnumber from cycle being scheduled (1 of 2, 2 of 2).

3. Enter the cafendar months of thequarter to be scheduled, in accordance with one of thequarterly groupings shown below. Groupings otherthan those shown are not acceptable.

JAN APR JUL OCTFEB MAY AUG NOVMAR JUN SEP DEC

4. Enter the number of the “QuarterAfter Overhaul” in the space provided. For example:a ship completing major overbaul during August 1969will list the months of July, August and Septemberfor the first Quarter after overhaul schedule. Thesecond Quarter of the overhaul would then list themonths of October, November, and December. Whilein overhaul, ships must continue PMS whenever pos-sible. Ships departing major overhaul late in the quafierare not expected to complete all planned maintenancescheduled during that quarter, but should accomplisha proportionate share based on the time remaining inthe quarter. When departure occurs within the lasttwo weeks of the quarter, ships will complete thatquarter to the maximum extent possible utilizing thecurrent quarterly schedule. The first quarter after over-haul in this case will then begin with the next quarter.

5. Identify a date for the starting ofeach week. The main body of the Quarterly Scheduleis divided into thirteen columns; each column repre-sents a week. Each column is further divided intoseven days by the use of check marks across the topof the columns. Write directly over the first checkspace of each week to identify the date of eachMonday.

6. From the ship’s operational em-ployment schedule enter the following information:

a. Across the top of the columnslightly shade in the days that the ship expects to beunderway.

b. Across the bottom line of thecurrent Quarterly Schedule, write in the type of em-ployment, corresponding to the dates indicated across

the top columns. (Upkeep, ASW, ISE, TAV, etc.)7. Place the new Quarterly Schedule

next to the Cycle Scbedule.8 From the Cycle Schedule, select

the “Quarter After Overhaul” column correspondingto the current quarter. Penodicity codes listed in thiscolumn and the column titled “Each Quarter” willbe transcribed to the current quarterly schedule.The other columns on the cycle Schedule will notaffect the current quarter.

9. Refer to the MIPs for a brief de-scription of the maintenance actions scheduled on thecycle schedule in order to determine if the actionshould be performed in port or at sea. Schedule therequirement on the Quarterly Schedule in the weekmost appropriate for accomplishment. Schedule aflrelated maintenance together.

10. From tbe Cycle Schedule columntitled “Each Quarter” schedule all monthly andquarterly requirements into appropriate weeks of theQuarterly Schedule. Next, from the “Quarter AfterOverhaul” column, schedule all annual and semi-annualrequirements. The ultimate goal in scheduling theQuarterly PMS requirements is to ensure the comple-tion of all necessary maintenance actions while main-taining a balanced workfoad within the frameworkof the ship’s operating schedule. When there arechanges in the ship’s operating schedule, maintenancerequirements may require rescheduling to fit the newoperating schedule.

11. Schedule afl cycle requirements forwhich the number in parentheses matches the quarterafter overhaul being scheduled.

12. The completed Quarterly Scheduleshafl be signed by the Department Head in the“Quarter After Overhaul” block. Fill in all header in-formation for the next quarter on another QuarterlySchedule form and place it beside the current schedulein the holder. This provides continuity for schedulingand planning on a long-range basis. This QuarterlySchedule serves as a directive for Work Center Super-visors for scheduling weekly maintenance. At the endof each work week, the Work Center Supervisor willcross-out (X) all maintenance requirements on theQuarterly Schedule that have been completed and willcircle (0) afl requirements that were not accomplished.The Department Head is responsible for the resched-uling of all circled requirements, if they remain withinthe same penodicity (i.e., a monthly can only be re-scheduled in the same month, a quarterly can only berescheduled within the same quarter, etc.). Any re-quirement which cannot be accomplished during the

MAINTENANCE CONCEPTS NAVSEA SEOOO-OO-EI M-160 GENERAL MAINTENANCE

current quarter, in addition to being circled, shallbe identified on the back of the quarterly schedulewith the reason it was not accomplished. Other un-accomplished requirements shall be rescheduled foraccomplishment in the next quarter. The completedQuarterly Schedule is removed from the holder after theclose of each quarter and retained as a Planned Main-tenance record. This record may be discarded byquarters, when the same number quarter after thenext major overhaul has been completed, thereby pro-viding a complete cycle of history. Maintenance re-quirements shall not be rescheduled on the subsequentQuarterly Schedule until the ship’s employmentschedule is known or until the last week of the currentquarter, whichever comes first.2-2.2.1.6 Weekly Schedule

The Weekly Schedule (OPNAV Form4700/6), shown in Figure 2-6, is a visual display ofplanned maintenance scheduled for accomplishmentin a given Work Center during that week. The WeeklySchedule is posted in each Work Center and is usedby the Work Center Supervisor to assign and monitorthe accomplishment of the required PMS tasks by theWork Center personnel. It contains the name of theWork Center concerned, a listing of the systems, sub-systems, and components assigned to the maintenancegroup of the Work Center, and the respective equip-ment codes. It lists the maintenance requirement to beperformed in a specific week, the names of the person-nel assigned to individual maintenance actions, and theoutstanding repairs, PMS checks (Monthly and above),and known Situation Requirements due in the nextfour weeks. The procedure for filling out the WeeklySchedule is as follows:

1. Type in the following informationfrom the current Cycle Schedule.

a. Work Center identification, e.g.,Radio # 1 and corresponding cycle schedule sheetnumber (e.g., 1 of 2, 2 of 2).

b. System, subsystem or compo-nent and MIP number, line for line to match the cycleschedule.

2. From the MIPs enter the recurringweekly and daily requirements. Weekly requirementsshould be entered on Monday to provide ease of re-scheduling. Daily requirements must appear each day.

3. Place clear plastic over the weeklyschedule.

4. From the current Quarterly Sched-the Work Center Supervisor transposes all PMS re-quirements and the date for the current week to theWeekly Schedule. Exercise care to ensure a balancedworkload, appropriate consideration of the week’s

2-12

operating schedule, and that all related maintenanceactions are scheduled together. Review MIPs/MRCsand determine related maintenance requirements.

5. Using information from theQuarterly Schedule, fill in the “Outstanding RepairsDue” column (right column) with known correctivemaintenance and all Monthly (and above) PMS re-quirement due in the next four weeks. This shouldinclude all PMS Situation Requirements which maybe accomplished during that four-week period.

6. Assign maintenance personnel, byname, to specific maintenance tasks. Maintenancepersonnel will then obtain their PMS assignmentsfrom the Weekly Schedule, obtain the required MRCcards, tools or material, and perform the maintenanceaction. They must report all completed maintenanceaction to the Work Center Supervisor. The WorkCenter Supervisor will then cross off all completedrequirements when reported and will circle the un-completed requirement for rescheduling as the workload and ship’s operations permit. At the end of eachweek, the Work Center Supervisor should bring theQuarterly Schedule up to date by comparing it to theweekly schedule, crossing out completed require-ments and circling requirements not completed. TheWeekly Schedule is then erased and the next week’sschedule prepared.2-2.2.1.7 Maintenance Control Board

The Maintenance Control Board is aprefabricated aluminum holder that contains a CycleSchedule, a current Quarterly Schedule, and a sub-sequent quarterly maintenance schedule for each main-tenance group. As its name implies, the MaintenanceControl Board presents a readily available summary ofthe current and planned status of shipwide preventivemaintenance for all interested personnel.2-2.2.2 Maintenance Data

Collection SystemThe Maintenance Data Collection Sys-

tem (MDCS) provides a means for recording the ex-penditure of resources (men, material and time)associated with certain categories of maintenanceactions. Maintenance personnel are provided a meansto record, at the source, designated informationpertaining to accomplishment of preventive or correc-tive maintenance actions. It also provides a systemfor processing significant maintenance and logisticinformation, and disseminates the results in the formof technical information for maintainability /reli-ability studies of operational equipment, and in theform of management information for improvingworkload planning and control. It incorporates theuse of coded data elements for data standardization

ORIGINAL

.

-.

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 MAINTENANcE CONCEPTS

bmlel BuekbyGROUP Commter Room WORK SCHEOULE FOR WEEK OF 4 Jan 1971 1 1/70

~~ IN TENANCECOMPONENT RESPONSIBILITY PAGE MONDAY TUESDAY wEONESDh Y T H U R S D A Y FRIDAY SAT/SUN ““’s’A”mG “C ” ’( R 5 ‘“o “’-CHECKS 0“, w NCXT . .E. K,

AN/UYA 5(XN-l)(V Hanraban El DIW1 DIQ1 D1 D1 DI D1

AN/UYA 6(XN-X(V Urban E2 WIM1 Q1 Al

RP-161/fuYK Franck E3 WIQI

RO-367(XN-l)iJY : NUZZIJ E4 DIW1 DIQ1 D1 D1 D1 D1

—

.

WEEKLY WORK SCHEOULE OPNAV FORM 4700/6 (%6S) S,” O* OF,U.HW A-*m,,* U.*. GO VE”NMEN, P“, ”,,.. O,,, cc, ,S6,-,4C-8,,, A.,,,

Figure 2-6. Sample Weekly Work Schedule

2-13

MAINTENANCE CONCEPTS NAVSEA SE OOO-OO-EIM-160 GENERAL MAINTENANCE

and facilitating automatic data processing. Failureand corrective action information recorded on themaintenance action documents and the material usageinformation recorded on associated supply systemissue documents, is retrievable through this systemfor use in engineering analysis and developing main-tenance actions (deferred actions) and indicatingthe principal reason for the delays. This informationis also retrievable for use in maintenance problem andlogistic support analysis and for developing a CurrentShips Maintenance Project (CSMP) file which will as-sist in improving the planning and coordination of theship’s workload. For those maintenance actions whichhave been deferred because of a requirement for tech-nical skills or special equipment not available on boardship, the MDCS makes provisions for documenting awork request to an appropriate repair activity. Follow-UP reporting by these repair activities, upon comple-tion of requested repair assistance, contributes signifi-cantly to the detail and depth maintenance informa-tion available for retrieval and subsequent use throughMDS. The reports and forms used in MDS are employ-ed in the following subsections.2-2.2.2.1 PMS Feedback Report

The PMS Feedback Report (OPNAVForm 4700-7), shown in Figure 2-7, provides a directline of communication, via the TYCOM, between themaintenance man and the Naval Material Command.The PMS Feedback is utilized to submit recommendedmodifications and revisions to PMS documentationand to request certain additional or replacementsoftware and hardware. In addition, it is used to sug-gest changes to technical manuafs and to report or in-quire about other matters in connection with PMS.Instruction for completing and submitting reportsare printed on the back of the last copy of this five-part form.2-2.2.2.2 Maintenance Data Form

The Maintenance Data Form (OPNAVForm 4790/2 K), shown in Figure 2-8, is a multipurposeform used to report the completion or deferral of amaintenance action or to request needed assistance.The data element that must be completed to reportany one of the categories of maintenance informationare grouped together in separate, clearly labeled sec-tions on the form, to simplify data recording and to fa-cilitate Automatic Data Processing (ADP). In additionto the standard data elements which are used for re-cording all reportable maintenance actions, this formprovides special shaded sections for recording other

2-14

necessary data elements for maintenance actionsassociated with specially identified systems or equip-ments, or reports completed under certain uniquecircumstances. This form supersedes OPNAV Forms4700-2J, 4700 -2 B,4700-2C, and 4700-2D.2-2.2.2.3 Supplemental Report Form

The Supplemental Report Form(OPNAV Form 4790/2L), shown in Figure 2-9, is anMDS feedback report used to inquire about,or commenton, any subject related to maintenance accomplish-ment or maintenance action reporting. In this applica-tion, this report may be used individually or in con.juction with OPNAV Form 4790/2K. This form hasbeen approved by CNO as the reporting form forlimited duration data collection programs. This formpermits collecting more detailed maintenance in-formation than is available through routine MDSreporting. Section I of this form is filled in the sameway as on associated form 4790/2K if it is being usedas a continuation sheet. Otherwise, only block 1,date and serial number, is required. Section II isfilled in with the voluntary information being reported.It should contain comments, sketches, technical data,etc. When required for mandatory submission, this sec-tion will be filled in as directed by appropriate author-ity. Section III is for signature use as indicated or asdirected for special report use. Section IV is reservedfor special reporting programs only and shall be filledin according to instructions. Section V is for ad-dressing; use as indicated unless otherwise directedfor special reporting.2-2.2.2.4 Work Supplement Card

The Work Supplement Card (OPNAVForm 4790/2 F), shown in Figure 2-10, is a prepunchedpre-printed card supplied to the Lead Work Center andeach assist work center included in the initial planningphase of the Work Request. This card is used primarilyby repair work centers to report the daily progress(action taken, manhours expended, date) on a workrequest. This card may also be used to record remain-ing hours, report work delay/status and to requestadditional work supplement cards. The assist workcenter will use the same card to estimate their portionof the job. Information from these cards is used forWorkload Planning and Control (WLP&C) reports.

1. Daily Progress. The Work Supple-mental Cards are used to document all manhours ex-pended on each job in progress within the work center.The senior man actively engaged in the maintenance ac-tion is responsible for documenting the daily progress.

%9

L


— —

I

ORIGINAL

INSTRUCTIONS ON BACK OF GREEN PAGER O M : USS Worcester

SERIAL#. C-69O: NAVY MAINTENANCE

MANAGEMENT FIELD OFFICEDATE 15 NOV 1970

Box 604 H a m p t o n R o a d s B r a n c h

N o r f o l k , V i r g i n i a 2 3 5 1 11A:

SUBJECT: PLANNED MAINTENANCE SYSTEM FEEDBACK REPORTYSTE&l CO MPCNLNT

AN/UYA 5 (XN-l)(V) M e m o r y

tiB-sys TEM‘“‘“ ‘“MBE%-17 M l

coNTFOL ‘0 ” 8 6 4 3 7 6 ‘-

‘DISCREPANCY:

❑ M. R. Description ❑ EquipmentChange ❑ Typographical

❑ Safety Precautions• 1t&yn:ag:’;;;;nce a ;::!:%,

❑ Tools, E+., ❑ Technical ❑ Miscellaneous

❑ ~j;;;@##~~;~;;RC) ❑ Procedure

L o g i c D i a g r a m s i n 0 9 6 7 - 3 0 6 - 4 0 2 0 a r e i n e r r o r . G a t e

number 6D5A has ou tpu t p in shown as 14 . This p in should

b e 1 3 .

bduSIG NATUR~

rHIS COPY FOR:

11.8AU $no~ A7110/7 (Raw R-A&\,.-. , --.,, -. -“. , ,---- - --,

c->’ /ADDRESSEE 1

Figure 2-7. Sample PMS Feedback Form

2-15


OPNAV FORM 479012K(R,” 1-701 MAINTENANCE DATA FORM UAIIIT2NAIIC2 KlW41

(JJ3 A Uc N @ 76fJ_

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SHIP UU#E/HULL UUM8CRJOS CONIWOl. MMB2R I SECTION I r A : •~R20 INFOSMTUN

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SECTION III- DEFERRAL ACTION PLANNING>2 AIT 23 m, IlcNms I(IO 2,. RA7W:R@lC 25

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121 1 1 1 ! , I , I , , , , , , , , 1 , 1 , t I 1 1 I

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SECTION - AlLED PARTS /COMPONENT

SECTION IZ - SUPPLEMENTARY INFORMATION@, KUE?RIWIS, TCCN MA#UhLS, ?LAUS, ETC, AWLABLC m. ?REAR” IvAL M O / O R bR@!”AL COMFIRUCi AC1l M. REMARKS ,,

cu m.,,

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Figure 2-8. Sample Maintenance Data Form

2-16 ORIGINAL

GENERAL MAINTENANCE NAVSEASEOOO-00-EIM-160 MAINTENANCE CONCEPTS

L

.

2. Remaining Hours. Whenever the re-maining hours, as listed on the WLP & C reports, do notaccurately reflect the scope of the job for this workcenter, this figure can be revised by entering the hoursremaing for the job in block D of this form. The workcenter supervisor must concur with the new entry.

3. Work Delay. Work delays or workstoppage affecting satisfactory progress on the job isreported by using the Work Supplement Card. TheLead Work Center or the Assist Work Center mayuse the Work Delay/Stoppage Codes, found on the re-verse side of the card, in block G. T~ere can be onlyone Work Delay/Stoppage Code effective at any onetime for any specific work center. The latest delaycode that is submitted will be reflected on WPL & Creports. The delay code 00 will be used to show thedelay status from that work center WPL & C re-ports. The Work Center Supervisor must. concur withassignment and removal of delay codes.

4. Replenishment. Request for replen-ishment of the supply of Work Supplement cardscan be accomplished by submitting a card for thatspecific purpose or in conjunction with the dailyprogress report by entering the number of cards desired(1 to 9) in block H.

5. Assigning an Assist Work Center.When additional repair work centers are required tocomplete the requested work, the Lead Repair WorkCenter will provide to Assist Repair Work Center twoor more pre-punched/pre-printed Work SupplementCards One is to establish the Assist Repair Work CenterJob Planning Record, and the others are for reportingprogress prior to receiving additional cards from DataServices. The Lead Repair Work Center will make theentries indicated on each card. The Lead Repair WorkCenter will provide sufficient description in theremarks section of the card to enable the Assist WorkCenter to scope the job.

6. Multiple Units. Multiple Unit workrequests on items such as binoculars, printing, photo-graphing, plaques, sound-powered phones, clocks,etc., are permitted by using the words “various” or“miscell” in block 9 of the work request submitted ona 4790/2K form. Block 9 of the pre-punched 4790/2Fcard will always be blank when associated with thistype work request. These multiple items will always bedocumented as a single maintenance action unless re-jection of individually serialized items is involved.

ORIGINAL 2-17

When individually serialized items are rejected, the Re-jection Action Taken Code must be on a one-for-onebasis for each item. For non-serialized items or wheneverrejection is not involved, the Action Taken Code thatbest describes the overall effort will be recorded. ksistWork Centers will not reject individual units of a multi-ple unit work request, Multiple unit work requests onmaintenance history significant items are not permitted.

7. Completion. Completion of a workrequest can be reported using the 4790/2F and enteringthe code’’3O” in block G. Assist Work Centers may alsoreport completion of their portion of a job by usingcode “30” in block G on the 4790/2F. When code“30” is received by Lead Work Center, sheet 1 of the4790/2K must be completed for the job to be closed out.2-2.2.2.5 Failed Parts/Components Card

The Failed Parts/Component Card(OPNAV Form 4790-2M), shown in Figure 2-11, isused to document a failed part or component only whenblock 29 on the OPNAV 4790/2K (Work Request) in-dicates this requirement with an entry. One pre-printed4790-2M card is provided the Lead Work Center forthis purpose. It is the Lead Work Center’s responsibil-ity to document failed parts/components includingthose discovered by Assist Work Centers. A maximumof three failed parts/components will be reported.When there are more than three, the Lead Work Centerwill determine and report the three most insignificantfailures in the order of their importance.2-2.2.2.6 Single Line Item

Requisition DocumentThis document (DD Form 1348), shown

in Figure 2-12, is used for internal issue of material a-aboard ships that have automated (mechanical) supplyrecords with Automatic Data Processing (APD) equip-ment. The procedure for filling out this document isas follows:

1. Enter the Job Control Number(JCN) in blocks L, M, and N. The JCN is made up fromthe Unit Identification Code (UIC), Work Center (WC),and the Job Sequence Number (JSN) contained inblocks 1, 2, and 3 of OPNAV Form 4790/2K per-taining to the maintenance action for which the itemis requested. Care must be exercised to ensure thatthe same JCN is used on all supply documents relat-ing to the same maintenance action.

2. Enter the National Stock Number(NSN) in blocks 4, 5 and 6 for the item requested.


OPNAV FORM 47$3/2L SUPPLEMENTAL REPORT FORM CONTINUATION(REV. 1-70)s/ N-o 107-770-3053

mm

UJ3 B UC k- (pP 74/]SHIP NAdE/H!JLL NUMBEti

OEXJ3”- 3SER8AL NUMBER (OPTIONAL USE)

J O B C O N T R O L N U M B E R 1 SECTION I

M91619 Eiiziil

SECTION Ill - SIGNATUREM A I N T A I N E R R E P O R T I N G : S U P E R V I S O R !

SECTION IV . SUPPLEMENTARY INFORMATION (FOR USE ONLY WHEN DIRECTED BY REQUIRING ACTIVITY)

1 I I 1 I 1 i 1 I I ~ I I i i / J 1 I .1*.

I I I I t i I I

1 II

*.,:.,. ‘,;:

I I 1 I I I { I ~ i 1 I 1 1 1 1 [ I f : ! I 1 I 1

1 1 \ ! 1 1 I I i I I I { I I I I IJ 1 1 “1 I I i I l’ -.

SECTION V - MAILING ADORESS (FILL IN ACCOROING TO “DIRECTIONS- OR AS MOOIFIEO BY REQUIRING ACTIVITY)TO, VIA,

N w’wo (61 —c fLD~ ~~b~ G & & ( ~~r]

6 ~i= .@UII~ DGK&L<jSSAI 6$? ~!a~@Ji}c <Ls#$~

JMP7LMJ Roam &RfMl nk s. wPour. fl.z.

o6rl?L k. VA ~ 2s- 114J?Yx&??15ff

d

Figure 2-9. Sample Supplemental Report Form

2-18 ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 MAINTENANcE CONCEPTS

H,. ‘m”

OPNAV Form 4790/2F Work Supplement Card (Front)

CODE WORK NOT STARTED11. Not Delivered to Work Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “NOT DELI~RED>s12. Insufficient Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . yNSUFF INFO ,,13. Awaiting Parts/Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “WAITG pARTS/MATL>$14. Lack of Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ‘*LACK MANpO~R,:15. Work Center Equipment Unavai2atrle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “WC EQUIp UNAVAIL ‘

WORK STARTED BUT STOPPED21. Priorty Changed . . . . . . . . . . . . . . . . . . . . . . . . “STP-PRIORITY CHANGE”22. hrsufllcient Information . . . . . . . . . . . . . . . . . . . . . . . . . j J J : J : 1 . ; n J 1 1 u . . . . ‘,S-fp-INSUFF INFO~,23. Awaiting Parts/Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “STP-WAITG PARTS/MATL”24. Awaiting Assist Work Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “STP.WA2TG ASSIST WC”25. Work Center Equipment Unavailable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “STP-WC EQulp UNAVAIL,>

STATUS CODES10. Completed–Not Signed Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “COMPL-NOT SIGNED OFF’S10. Re-Work Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6$ RE.WORK REQUIRED,*$@59. Special Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ SPECIAL STATUS”

OPNAV Form 4790/2F Work Supplement Card (Reverse) Work Delay and Status Codes

Figure 2-10. Sample Work Supplement Card

7.1~


—..— . . . . . . ... ..-. .= —.-.— ..—

I ,.,, ID Cca Iumaawl’cm as.mm F E9u.1 D. CC.U r WAIRWC

SECONDARYc.. I_! -u ~’ “,.

l“-,.. ..”.,.

I-nl ‘m-“. ..I.OL

I i I I I I I I I r- I El

Figure 2-11. 8ample Failed Parts/Components Card

I II I I 1..,,1 II I I 111 I I 1!11 I I I.!:... ,% i$ ‘ ‘ ‘ ‘;:Oc”r:oM’::D’LL’dw-”%cS E N D T O : RrxnJsTlON I s FROM: ,..

i‘

I -D,!,** 1

Figure 2-12. Sample DD Form 1348

.— ------ . . . . . . . . . . . . . . . . . . . . . . . . -- . . - . . . . . - ...— ------ -- - --- - -- . . . ... —-.. - ---- --- --————. . . . - --- . --s-- -- . . . . . . ““ ,., -,,. , -,. m , ” ”k ““, ””L, , Q

The FSN is generally found in the Coordinated Ship-board Allowance List (COSAL) within the AllowanceParts List/Allowance Equipage List (APL/AEL) for theequipment/component being worked on. When onlythe part number is known, the NSN may be obtainedfrom the Master Cross Reference List (MCRL). Whenan item is identified only by the Manufacturer’sPart Number for which no NSN has been assigned,the part number preceded by the Federal Supply Codeof Manufacturers (FSCM) will be entered. When arequested item cannot be identified by an FSN or aManufacturer’s Part Number, the Noun Name and abrief description of the item will be provided in blocks4, 5, and 6.

3. Enter the quantity of the item re-quired in block 8. Provide the actual quantity re-quired, consistent with the standard unit of issue, tocomplete the maintenance action.

4. Enter the Document Number inblocks 10 and 11. The document number contains twodata elements. In block 10, enter the department/division serial number. In block 11 enter the Juliandate of the day that the request for the item wasplaced with the Supply Department.

5. Enter the urgency code in block20. This code shall be a realistic code assigned by per-sonnel designated by the Department Head.

6. When the item requested is Not InStock (NIS) or Not Carried (NC) and it is imperativethat the item be on board by a certain date in order tocomplete the maintenance action to meet ship’s opera-tions, enter the Required Delivery Date (RDD) inblock 21. This date shall be a realistic date and assignedby personnel designated by the Department Head.

7. Enter the Equipment Identifica-tion Code (EIC) in blocks P and Q. The EIC code isobtained from the EIC Manual and should be theLowest Designated Assembly (LDA) listed in the EICManual for the item requested. The EIC used heremay not necessarily be identical to the EIC used on the4790/2K.

8. Enter the APL and AEL code inblocks R and S. These codes are taken from the ship’sCOSAL. Exercise care to ensure that the APL/AEL isfor the equipment/component actuafly being workedon. This entry may not necessarily be identical to theAPL/AEL entry on the 4790/2K. In a case where theAPL/AEL does not exist on board, enter “Not Listed.”

9. Enter the Reference Circuit Symbolfor the part or item in block U. This reference/circuitsymbol may be found on schematics, circuit diagrams,and technical manuals. Further documentation of the

ORIGINAL 2-

DD Fonu 1348 will be accomplished by the SupplyDepartment. After appropriate action has been takenby supply, the maintenance technician will receive acopy of the DD Forru 1348 with the material requested.In cases where the material is not available on board,the WC will be provided with a copy marked NIS orNC as appropriate for the WCs status information.2-2.2.2.7 Single Line Item Consumption/

Management DocumentThis document (NAVSUP Form 1250),

shown in Rgure 2-13, is used to request and issuematerial internally aboard ships that do not haveautomated (mechanized) supply records. A copy ofthis form is used to report all maintenance relatedmaterial issues. The procedure for tilling out thisdocument is as follows:

1. Enter the material request date inblock A. This entry will be the Julian date of the daythat the request for the item is placed with the SupplyDepartment.

2. Enter the Department Number inblock B. This number is the next sequential number foreach transaction of the department issuing the request.

3. Check the word “Issue” in blockC to ensure proper reporting of the item used.

4. When the item requested is Not InStock (NIS) or Not Carried (NC) and it is imperativethat the item be on board by a certain date in orderto complete the maintenance action to meet shipsoperations, enter the Required Delivery Date (RDD)in block I. This date shall be a realistic date and as-signed by personnel designated by the DepartmentHead.

5. Enter the Urgency code in block J.This code shall be a realistic code assigned by personneldesignated by the Department Head.

6. Enter the National Stock Number(NSN) in blocks 3, 4, and 5 for the item requested.The NSN is generally found in the Coordinated Ship-board Allowance List (COSAL) within the AllowanceParts List/Allowance Equipage List (APL/AEL) forthe equipment/component being worked on. Whenonly the part number is known, the NSN may be ob-tained from the Master Cross Reference List (MCRL).When an item is identified only by the Manufacturer’sPart Number for which no NSN has been assigned, thepart number preceded by the Federal Supply Code ofManufacturers (FSCM) will be entered. When a re-quested item cannot be identified by a FSN or aManufacturer’s Part Number, the Noun Name and abrief description of the item will be provided in blocks3,4, and 5.

21


7. Enter the Reference Circuit Symbolor Noun Name for the part or item in block 6. The ref-erence symbol may be found on schematics, circuitdiagrams, and technical manuals.

8. Enter the quanti@ of the item re-quired in block 8. Provide the actual quantity required,consistent with the standard unit of issue, to completethe maintenance action.

9. Enter the Job Control Number(JCN) in blocks 10, 11, and 12. The JCN is made upfrom the Unit Identification Code (UIC), Work Center(WC), and the Job Sequence Number (JSN) containedin blocks 1, 2, and 3 of OPNAV Form 4790/2K per-taining to the maintenance action for which the itemis requested. Care must he exercised to ensure that thesame JCN is used on all supply documents relating tothe same maintenance action.

10. Enter the Equipment IdentificationCode (EIC) in block 13. The EIC code is obtained fromthe EIC Manual and should be the Lowest DesignatedAssembly (LDA) listed in the EIC Manual for the itemrequested. The EIC used here may not necessarilybe identical to the EIC used on the 4790/2K. In acase where the APL/AEL does not exist on board,enter “Not Listed. ”

11. The Approval Signature will heplaced in block U. This block requires the signature ofthe Department Head or personnel designated by him.

Figure 2-13. Sample NA

2-

12. When the item is issued by supplypersonnel, the maintenance technician receiving theitem will sign his name in block V as proof of de-livery for the Supply Department. Further documen-tation of the NAVSUP Form 1250 will be accomplish-ed by supply personnel. After appropriate actionhas been taken by supply, the requesting maintenancetechnician will receive the yellow copy with thematerial. In cases where the material is not available onboard, the maintenance technician will receive theyellow copy marked NIS or NC as appropriate.

2-3 OPERATIONALMAINTENANCE

Operational maintenance consists of in-spections, cleaning, servicing, preservation, lubrication,adjustment, and minor parts replacement not requir-ing a high degree of technical skill or knowledge.

2-3.1 OPERATOR RESPONSIBILITIESVery often, a competent equipment op-

erator can see or sense a malfunction in an equipmentwhich he can correct without the aid of a technician.He is qualified to make some adjustments and changesto an equipment, provided they do not require a highdegree of technical skill. Further, he may be requiredto perform the following duties:

-.

VSUP Form 1250

22

GENERAL MAINTENANCE NAVSEAsEooo-oo-EInl-160 MAINTENANCE CONCEPTS

1. Carry out routine maintenance such

as lubrication and cleaning.2. Maintain an adequate, up-to-date,

and accessible list of replacement parts.3. Log all the work performed on an

equipment, including all significant measurementsthat are taken.

2-3.2 TECHNICIANRESPONSIBILITIESA technician performs the tests, adjust-

ments, and repairs that are beyond the ability of theoperator. A technician must do maintenance workthat involves internal alignment, disassembly, andcritical adjustment. He must perform tests and fol-low procedures as required by PMS and the technicalmanual.

2-4 TROUBLESHOOTING FORCORRECTIVE MAINTENANCE

Corrective maintenance is the correctionof equipment troubles, whether this be the repair ofan equipment after a complete breakdown or the tun-ing and adjustment of an equipment necessary to re-store it to an operating condition. Before correctivemaintenance can be performed, operators and tech-nicians must know that the trouble exists. Sounds likean erroneous statement? Numerous instances have oc-curred where obviously malfunctioning equipmentswere operating for hours, days, and even months with-out the symptom of the malfunction being recognizedby either the operator or technician. Of course, nocorrective actions were taken.

2-4.1 SYMPTOM RECOGNITIONSymptom recognition is the first step

in troubleshooting, and is based on a complete know-ledge and understanding of equipment operation andoperational characteristics. In many cases, this is theresponsibility of an operator even though he hasno technical background. For an operator to recog-nize a symptom of malfunction, he must be thoroughlyfamiliar with proper equipment operating techniques,and know the function of each mode and feature, evenof those rarely used. Symptom recognition may bedifficult under electronic countermeasures attack,but consider the probable consequences if correctiveaction was not taken, or the symptom was not re-ported to a technician. In many cases, a mode changeor the adjustment of an operator’s control is all that

ORIGINAL 2 - 2

is needed. Not all equipments produce symptoms thatare easily recognized. This type of equipment troublemay then be discovered while performing preventivemaintenance under a planned maintenance program,such as PMS. It is important that the “not so apparent”as well as the apparent troubles be recognized.Operators who are not technically qualified technicianson the equipment they operate are still responsiblefor reporting a malfunction or a symptom to theelectronics technician.

2-4.2 SYMPTOM ELABORATIONAfter an equipment trouble has been

recognized, all the available aids designed into theequipment should be used to further elaborate on thesymptom. Use of front panel controls and otber built-in indicating and testing aids should provide betteridentification of the symptom. The equipment op-eration section of technical manuals may serve as aguide.

2-4.3 LISTING PROBABLEFAULTY FUNCTIONSThe next step in troubeshooting is to

formulate a number of logical choices as to the basiccause of the symptom, or what function is at fault.The logical choices should be mental decisions basedon knowledge of equipment operation, a full identifi-cation of the symptom, and information contained intechnical manuals. The overall functional descriptionwith associated block diagrams of technical manualscan help the electronics technician formulate logicalchoices.

24.4 LOCALIZING THEFAULTY FUNCTIONLocalizing the faulty function is

normally accomplished by using the diagrams in tech-nical manuals. For the greatest efficiency in local-izing the trouble, the logical choices should be testedby following the signal flow of a function through thediagrams in an order that will require the least time.If one test does not prove that a particular functionis at fault, the next choice should be tested, and so on,until the faulty tlmction or basic cause of the symp-tom is located.

2-4.5 LOCALIZING TROUBLETO THE CIRCUITOnce the faulty function is determined,

it may be necessary to make additional choices as to

3


which circuit, or group of circuits, is at fault. Again,the diagrams supported with these parameters areused, along with schematics and other test locationinformation that may be helpful in bracketing thefaulty circuit. If the trouble is not immediately ap-parent, test methods are then necessary to furtherisolate the fault. The most common test methodsare waveform analysis, voltage checks, resistancechecks, tube testing, and semiconductor testing.Briefly, they are explained in the following subsections.2-4.5.1 Waveform Analysis

Waveform analyses are made by ob-serving voltage and current variations with respect totime. The cathode-ray synchroscope is a device thataccurately displays the voltage variations with respectto a time-base that is synchronized internally by itaown circuits or externally by other synchronous sig-nals. Numerous types of synchroscopes (commonlycalled oscilloscopes) are available, the required onebeing supplied with each equipment. The synchroscoperequired for particular types of tests is determinedby characteristics such as the bandwidth of the inputfrequency, the input impedance, the sensitivity, thesweep rate (time base), and the methods of sweepcontrol (synchronization).2-4.5.2 Voltage Checks

Voltage measurements, when comparedwith available voltage charts, provide a valuable aidin locating the trouble. However, the sensitivity ofsome test voltmeters differs from that of the volt-meter used to make the charts. In such cases, therewill be a discrepancy in voltage readings, and theymust then be evaluated before the true circuit condi-tions can be determined. A voltmeter of low sensi-tivity may disturb a circuit or even render it inoper-ative.2-4.5.3 Resistance Checks

Resistance changes are often the causeof a malfunction and degraded performance. Thechange in a resistance can then be detected by measur-ing the dc resistance with an ohmmeter between agiven point and a reference (usually ground). Point-to-point resistance charts are provided in the technicalmanuals. Extreme caution should be used when makingresistance checks in transistor circuits as the transistormay be damaged by ohmmeter battery voltage.2-4.5.4 Tube Testing

Electron tubes are more prone tofailure than are any other electronic component. It isunwise, however, to attempt to make a general tubecheck in an equipment containing a large number of

2-2

tubes. Before tube testing is attempted, the area oftrouble should be localized as much as possible toavoid excessive tube testa. Only the tubes in a circuitjudged to be faulty should be tested along with tubesassociated with the faulty circuit. When replacing atube, equipment control settings should be notedbefore insertion of a new tube. A new tube shouldalways be tested for gas or for shorts before insertion.If, with the new tube, the equipment performs ab-normally and changing the control setting does notcorrect the trouble, the original tube should be rein-serted, provided that it did not prove defective on a re-liable checker. Tubes should not be swapped atrandom, as the interelectrode capacitance of a tube isa factor in a tuned circuit, and indiscriminate swappingmay detune certain circuits. Also, sockets and tubeprongs are bound to be damaged from excessive swap-ping.2-4.5.5 semiconductor Testing

Transistor, unlike vacuum tubes, arevery rugged in that they can tolerate vibration and arather large degree of shock, and under normaloperating conditions will provide for a long period ofdependable operation. However, transistors are subjectto failure when subjected to excessive temperature andminor overloads. To determine the condition of semi-conductors, various test methods are available. In manycases it is possible to substitute a transistor of knowngood quality for a questionable one, and thus deter-mine the condition of a suspected transistor. Thismethod of test is highly accurate and sometimes ex-peditious for plug-in types. However, indiscriminatesubstitution of semiconductors in critical circuits is tobe avoided. When transistors are soldered into equip-ment, this substitution becomes impracticrd; it is gener-ally desirable to test these transistors in their circuits.Since certain fundamental characteristics are an indi-cation of the condition of semiconductors, test equip-ment is available for testing these characteristics withthe semiconductors both in and out of their circuits.

2-4.6 FAILURE ANALYSISAfter the faulty component, misalign-

ment, etc., has been located, but prior to performingcorrective action, the procedures followed up to thispoint should be reviewed to determine exactly why thefault affected the equipment in the manner it did.This review is usually necessary to make certain thatthe fault discovered is actually the cause of the mal-function, and not just the result of the malfunc-tion.

4 ORIGINAL


2-5 ALTERATIONS

An alteration is any change in hull,machinery, fittings, or equipment which involveschanges in design, materials, number, location, or re-lationship of the component parts of an assembly, re-gardless of whether undertaken separately or togetherwith repairs. Changes in allowances of installed equip-ment are alterations and should be so handled. Theword “approve” in connection with an alterationindicates the Command’s action on the proposedchange. Command approval is promulgated in lettersof technical instruction or SHIPALTS. Approvalalone, however, does not constitute authority to pro-ceed with the work. The word “authorize” is used tosignify the Command’s permission to proceed and thegranting of funds for a particular ship during a parti-cular availability. Alterations which affect the militarycharacteristics of a ship may be approved only by theChief of Naval Operations, who also establishes theirrelative priority for accomplishment. Alterationsother than those affecting military characteristics areapproved by the cognizant commands without refer-ence to CNO. In general, alterations of this type con-cern matters of safety, efficiency, and economy ofoperation or upkeep (recorded in the OperationalImprovement Plan), and health and comfort of per-sonnel (recorded in the Habitability ImprovementPlan). The command concerned is nsx.ponsible fordetermining whether military characteristics areinvolved. Alterations to vessels which are made neces-sary by changes in armament or by changes in equip-ment furnished by other commands are under thecognizance of the Naval Sea Systems Command.

2-5.1 SHIPALTSApproved alterations to ships under the

cognizance of NAVSEA are known as SHIPALTS.Each quarter, these we listed according to priorities(A, mandatory; B, essential; and C, desirable), com-piled as type priority lists, and forwarded to cog-nizant Type Commanders for information. ~peCommanders are requested to review outstanding ap-proved alterations annually and initiate action to can-cel those no longer considered essential. Priority listsare also forwarded to the cognizant naval shipyardsfor guidance in advance planning; for proceeding withdesign, procurement, and installation work; and forresolving conflicting demands upon personnel andfacilities. In order to facilitate record keeping in thecase of multiple building programs, alterations ordered

ORIGINAL 2-2

in ships under construction, which are also approvedas SHIPALTS for ships already delivered, are indicatedby including the ships under construction in the ap-plicable SHIPALT. This facilitates the orderly ac-complishment of these alterations after delivery incase they are not completed during the constructionperiod. Items omitted from master lists are assignedappropriate priorities at the time work is authorizedfor applicable ships, or upon request. NAVSEA reviewsoutstanding SHIPALTS for an individual ship in ad-vance of its scheduled overhaul period and issues,not later than 180 days before such overhaul, a listof the alterations authorized for accomplishment dur-ing the overhaul. The list is based upon available fundsand equipment. The order of priority follows, as faras practicable, that of the type priority lists. The TypeCommander and the commander of the overhaulingnaval shipyard are requested to comment upon thislist. Upon receipt of their recommendations, NAVSEAmodifies, as considered desirable, the original list ofauthorized alterations. SHIPALTS are issued onNAVSHIPS Form 4720/4 (formerly NAVSHIPS 99).Upon completion of an alteration, Section IV of the re-cord must be returned to NAVSEA with an endorse-ment reporting its completion and a statement to theeffect that the ship plans and technical manuals havebeen corrected to record the changes made.

2-5.2 OR DALTSOrdnance Alterations (ORDALTS) pro-

vide the standard means by which naval activities arefurnished plans, instructions, and material for accom-plishment of alterations or modifications to navalordnance material in service or in store. An ORDALTinstruction states the specific conditions of applicabilityof the ORDALT and the method by which theORDALT is accomplished. An ORDALT set providesthe material necessary for the accomplishment of theORDALT. Whenever possible, ORDALTS will beprepared in such a fasbion that they are unclassified,and can be accomplished by forces afloat without theassistance of contractor field engineer except as follows:

1. ORDALTS either too complex ortoo time consuming to be accomplished by forcesafloat will. be prepared, whenever possible, so thatthey are unclassified and can be accomplished by ship-yard personnel during ship availability.

2. In certain situations, contractorpersonnel (field engineers and/or installation teams)may be assigned to provide technical assistance or toaccomplish the ORDALT.

5


.-

2-6 FIELD CHANGES

Electronic Field Changes provide oper-ational, reliability, and maintainability improvementsto existing electronic equipment. In addition, assis-tance is provided in the areas of installation, identi-fication, and logistic support. These improvementa,which overcome deficiencies in design and material, areaccomplished after manufacture and deliveW to theNavy. Prompt accomplishment of all applicable fieldchanges is mandatory to the extent stated in theinstructions that accompany the field changes.

2-6.1 CLASSES OF FIELD CHANGESThere are three class designations (A,

B, and C) for field changes, one of which is assignedto each field change kit. They provide an abbreviatedmethod of indicating the funding and installation re-sponsibility. A Class A field change requires no instal-lation funding. These field changes are approved for ac-complishment (installation) by forces afloat or stationpersonnel on ship- or shore-installed equipment with-out further reference to the cognizant managementcommand, under conditions stated in the field changeinstructions. A Class B field change requires Fleet in-stallation funding (not applicable to shore-installedequipment except at training activities). Changes toshipboard equipment we approved for accomplish-ment by naval shipyards or repair facilities withoutfurther reference to NAVSEA, under conditionsstated in the field change instructions, when author-ized by Type Commanders. Changes to equipment attraining activities are approved for accomplishmentand funded by the appropriate systems Command. meissuance of field changes which require Fleet fundingfor accomplishment is discontinued. Except for class Bfield changes presently under procurement in the sup-ply system, or in lleet installation planning stage,this type of field change will no longer be issued.A Class C field change normally requires industrialassistance for installation, and requires the appropriateSystems Command installation funding. This classof field change includes, but is not limited to,

2-2

changes of an operationtd i m p r o v e m e n t n a t u r ewhich are to be authorized and accomplishedby SHIPALT in the Modernization Plan. Changesto equipment at training activities are approvedfor accomplishment and funded by the appropriateSystems Command.

2-6.2 TYPES OF FIELD CHANGESA ~pe I field change consista of the

publications material (field change bulletins and pub-lication corrections) and all parts, materials, and spe-cial tools required to accomplish the change to oneequipment and to revise existing equipment name-plates, publications, and charta. A ~pe H field changeconsists only of publications material required toaccomplish the change to the equipment and to reviseexisting equipment publications and charts. The pub-lications material may be promulgated in the form ofthe bulletins and correction material, or by means of apublished article. Type II changes may require theparts be requisitioned from stock. A Type III fieldchange consists of the publications material (fieldchange bulletins and publication corrections) and onlya portion of the parts, materials, and special toolsrequired to accomplish the change to one equipmentand to revise existing nameplates, publications andcharts. A Type IV field change consists of only publi-cations material required to accomplish the fieldchange to the equipment and to revise existing equip-ment publications and charts. The Type IV fieldchange information will be in the form of a publicationpackage, but may be promulgated in advance by meansof a published article such as in the ElectronicInformation Bulletin (EIB). Type IV field changes donot require the use of parts, materials, or specialtools.

2-6.3 RECORDING AND REPORTINGACCOMPLISHMENT OF FIELDCHANGESThe recording and reporting of field

changes shall be in accordance with the instructionsin the Field Change Bulletin.

6 ORIGINAL

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AND MAINTENANCE AIDS

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SECTION 3

ROUTINE MAINTENANCE AND MAINTENANCE AIDS

3-1 SAFETY PRECAUTIONS

Beforw attempting any repair or main-tenance work on electronic equipment, the equipmentmust be disconnected from the power supply and themain switch properly tagged so that it cannot be in-advertently energized. If there is any doubt as towhether the supply circuits have been deenergized, theyshould be checked with a voltmeter or voltage tester.Make certain that the power supply filter capacitom areshorted and grounded using an approved groundingprobe. Check the wiring diagram also to determine ifthere are any other capacitors that should be dis-charged by connecting their terminals to each otherand to ground by means of a shorting probe. An excep-tion to the rule for deenergizing the equipment may bemade when it is necessary to observe operation. In thiscase, observe the safety precautions necessary toprevent shock or arcs which might start fires, igniteexplosive vapom, or be injurious to the health ofpersonnel. Refer to articles contained in EIMB GeneralHandbook, NAVSEA SEOOO-OO-EIM-1OO, Section 3,for general electronic safety precautions.

3-2 ROUTINE MAINTENANCE

Routine maintenance is the applica-tion of special procedures of inspection, cleaning, andlubrication of an equipment or system on a scheduledbasis in order to keep an equipment or system at themost reliable and efficient operating level at all times.

3-2.1 CLEANING AND INSPECTIONA regular schedule of cleaning and

inspection will go far toward ensuring trouble-freeoperation and the detection of incipient faults beforethey develop into a major source of difficulty. Cleaningprocedures are given in most electronic equipmenttechnical manuals and reference standards books.Where definite times for cleaning and inspection arenot specified in the instructions given in the applica-ble technical manuals for the equipment, each shipshould set up a schedule or periodic cleaning andinspection at intervals sufficiently short to keep theequipment ready for service. In setting up such aschedule, the following points should be considered:

ORIGINAL 3-1

1. All electronic equipment must becleaned to assure good performance; such cleaning isnot for appearance only.

2. Steel wool or emery in any formshall not be used on or near electronic equipment.

3. Sandpaper and files should not beused except as a result of competent advice.

4. A vacuum cleaner with a non-metallic nozzle and adequate dust receiver shouldbe used whenever practicable.

i% Solventa are to be used only whenabsohkely necessary and then only after proper safetyprecautions have been taken.

6. When cleaning, care must be exer-cised to avoid damaging components.

Dirt and foreign matter, if allowed tocollect on heat-dissipating components, act as thermalinsulators which prevent internally created heat fromdissipating into the air. When this occurs, the elec-tronic components thus affected operate at abnormallyhigh temperatures. This condition shortens the life ofthe component and thus precipitates a breakdown ofthe electronic equipment itself. Periodic cleaning ofthe interior of radio transmitted or other equipmentsemploying high voltage is particularly important.Potentials in excess of 3000 volts are often presentin these equipment, and dust on insulatom or otherhigh-voltage components forms a convenient path forarc-overs and consequent damage. In addition, amixture of dust and lubricant forms an abrasive whichcan cause considerable damage to moving parta.3-2.1.1 Ultrasonic Cleaning

Ultrasonic cleaning is rapidly becom-ing an accepted method of cleaning various shipboardelectrical and electronic hardware. Properly appliedand intelligently used, ultrasonics will do a more thor-ough cleaning job than any other method presentlyknown. For cleaning jobs, the utility of this tool islimited only by the size or weight of the part andingenuity of the person using it. As with any new tool,attention must be given to understanding the tool—how it works and how to make it work effectively.Basically, two things are required for any efficient andsatisfactory cleaning operation: the cleaning solution,and the method. Cleaning solutions are either water-based solutions or solvents. The method is how thesolution is applied: hand scrubbing, soaking, spraywashing, or ultrasonic cleaning. Ultrasonic cleaningutilizes both chemical and physical action. The proper

ROUTINE MAINTENANCEAND MAINTENANCE AIDS


solutions are selected first to loosen the chemicallybonded material. Ultrasonic cavitation of the solutionthen loosens the mechanically bonded material (dirt).Cavitation is a phenomenon in which vacuum bubblesare rapidly generated and violently collapsed in asolution. As these bubbles collapse, they exert a scrub-bing force against the surface of the part placed in thesolution. Detergenta play a large part in ultrasoniccleaning. Addition of a detergent to water decreasesthe amount of energy dissipated in cavitation. Additionof a wetting agent also accelerates degassing of thesolution. Some of the initial energy is consumed indegassing air from the solution before maximum cavi-tation is achieved. The air bubbles formed during de-gassing act as an energy sink which reduces the energygenerated by the ultrasonic transducer. Detergenta areof three basic types: alkaline, acidic, and solvent.Alkaline detergents generally consist of such alkaliesas caustic phosphates, silicates, carbonates and surfaceactive agenta. Cleaning solutions on board submarinesmust be limited to alkaline solutions to avoid atmos-pheric contamination. A satisfactory cleaning job cangenerally be done with alkaline detergenta. Acids andsolvents may be used in shipyard and repair ship ultra-sonic cleaners if the material used for the cleaningtank, drain valves, and piping is stainless steel ormonel. Generally, the solution that is best for cleaningthe part by conventionrd methods (soaking, flushing,and rinsing) is also best when using ultrasonics. To doa good cavitating job, cleaning solutions must meetthe following conditions:

1. Their density must be about thatof water or a little higher.

2. They must have a relatively lowvapor pressure at the working temperature of the bath.

3. They must remain thin-bodiedand nonviscous at operating temperature.

These three characteristics-density,volatility, viscosity—are important from the standpointof cavitation. Sonic energy levels are down to approx-imately one-sixth capacity in chlorinated solvents andone-tenth capacity in fluorinated solvents as comparedto water-based solutions. In addition, the followingconditions also affect cleaning:

4. Length of time in the ultrasoniccleaner (usually 15 minutes maximum).

5. Temperature of solution.6. Height of solution (depth of

immersion).7. Type of rinse (pressurized spray

is preferred type).8. Cleanliness of solution.9. Types of cleaning fixtures used

(baskets, subtanks, wire hangers, etc.).

3-2

10. Position of part (area to becleaned should be completely submerged in solution).

11. Line voltage fluctuations.12. State of cleaning solution (new

or used).For components saturated with oil,

presoaking in a hot detergent solution in a separatetank is highly recommended. This method removesexcess surface dirt and oils, thus lengthening the lifeof the ultrasonic cleaning solution and recirculationsystem filter. When a cleaning job requires a strongercleaning solution than is normally used, or a solutionthat is not compatible with materials used in the ultra-sonic cleaner, a small subtank or container should beemployed. The subtank material should be compatiblewith the cleaning solution. The subtank containing thesolution should be suspended in the cleaning solutionin the ultrasonic tank so that the bottom of the sub-tank is at least several inches away from the bottom ofthe ultrasonic cleaning tank. (The top of the subtankmust remain above the weaker cleaning solution inwhich it is partially submerged.) Glass beakers withcracks should not be used as a subtank because theultrasonic action will break the cracked container. Theloss in cleaning efficiency with a subtank is negligibleif the wall thickness of the subtank is equivalent to thewall thickness of the ultrasonic tank. Due to thesmaller amount of cleaning solution required, thismethod is less hazardous to operating personnel, anddumping the dirty solution is less of a problem. Highlycaustic cleaning solutions should not be kept in theultrasonic cleaner beyond the time required for a par-ticular cleaning job. After dumping the cleaning solu-tion, the drain system of the ultrasonic cleaner shouldbe flushed with fresh water. Copper drain pipe andbrass drain valves will be eroded by any standingcaustic cleaning solution. For the same reason, alum-inum parts or components should not be cleaned inhighly caustic solutions. The amount of air trappedin the cleaning solution affecta the intensity of cavi-tation and cleaning ability. Some of the initial energywill be consumed in degassing air from the solutionbefore maximum cavitation is achieved. Ultrasonic agi-tation will effectively degas liquids; however, thebubbles formed during degassing act as an energy sinkthat may rob a transducer of energy. Therefore, a newor stagnant solution must be degassed before fullultrasonic cleaning efficiency is realized. The time nor-mally required for degaasing detergent solutions isapproximately 15 minutes; fresh water may require asmuch as 30 minutes. Ability to recognize the degassedcondition for the various cleaning solution% comeswith experience. Flushing or rinsing the cleaned partis extremely important in the overall ultrasonic

ORIGINAL

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cleaning process. The detergent keeps the particles ofcontamination suspended in the cleaning solution.When the cleaned part is removed from the ultrasonictank, it becomes recontaminated by these suspendedparticles. Therefore, flushing or rinsing of the cleanedpart is required to remove these loose particles. Rinsingshould be in the direction opposite to the normal fluidflow through the filter. True cleaning is assured onlyby flushing or rinsing. Ultrasonics tdone is not thecomplete answer to cleaning problems, but it is auseful tool in the overail cleaning system. Since thetype and degree of contamination vary even for thesame application, no fixed process can be specifiedfor all conditions.3-2.1.2 Ultrasonic Cleaning of

Modular AssembliesThe choice of ultrasonic cleaning

equipment should be governed not so much by thetransducer type as by the intensity of cavitationneeded to perform a given task, and the reliability ofthe equipment under conditions of rigorous fielduse. A typical ultrasonic cleaning unit is one in whichthe frequency of the ultrasonic oscillator is approx-imately 20,000 Hertz. The amount of energy requiredby the transduce to reach this threshold of cavita-tion is naturally dependent on the efficiency of thetransducers, as well as the acoustic properties of theliquid, the frequency, the temperature, the presenceof standing waves, and other factors. For example,a good rule of thumb in selecting the proper generatoris to multiply the capacity of the tank (number ofgallons) by a quantity of 50 to 70, to derive therequired power in watta. After selection of the ultra-sonic cleaner and solution (see Table 3-1) for a par-ticular cleaning task, follow the procedural stepsbelow, in the sequence given.

1. Place the contaminated assemblyor parts (in a wire-mesh basket or suspended on a wirehook) into the cleaning emulsion contained in theultrasonic cleaning tank, and energize the ultrasonicequipment.

NOTE

Only baskets that are specif-ically designed for ultrasoniccleaning should be used. Suchbaskets are available fromequipment manufacturers.Avoid the use of small mesh,which has the tendency tocut down on the amount ofultrasonics.

ORIGINAL 3-3

2. Leave the immersed assembly orparts in the cleaning solution for approximately 2 to3 minutes (depending on the amount and type ofcontamination).

NOTE

Use immersion heaters toheat the solution to a suitabletemperature, depending onthe type of solution used.

3. Remove the assembly or partsbeing cleaned from the ultrasonic cleaning tank, andflush with fresh water (preferably warm or hot).

4. Drain the cleaning emulsion fromthe cleaning tank, and refill the tank with fresh water.

5. Place the assembly or parts (in awire-mesh basket or suspended on a wire hook) intothe tank of fresh water, to remove the remainingcleaning emulsion.

6. Remove the assembly or partsfrom the fresh water bath, and blow as much waterm possible from the cleaned parts with dry, filteredair at no more than 50 lb/in2 pressure.

7. Spray all surface areas with awater-displacing fluid.

8. After spraying, allow approxi-mately 20 minutes for the water-displacing fluid topenetrate the crevices and combine with the remain-ing water.

9. Blow the residual mixture ofwater and water-displacing fluid from the assemblyor parts with dry, heated air from a portable electricblower, or place into an air-drying circulating oven.

The electronic equipment can now bereinstalled and operated after drying and check-outof the unita and components. If the equipment can-not be returned to operational condition, it should besprayed again with the water-displacing fluid, and thedrying process repeated.

WARNING

Operating personnel shouldnot immerse their hands inultrasonic baths over longperiods of time, since someburning of skin tissue mayresult.

Although ultrasonic cleaning is not acure-all for cleaning electronic assemblies, when


PRINCIPAL USE

General cleaning of watercontaminants (finger-prints, buffing compoundsshop dirt, blood, animaland vegetable oils, inks,milk residues, chemicalsrdts and residues, carbo-hydrates, radioactive con-taminant, food particles,dried soaps).

Same as above, except toremove tartar, nicotine,hard soap deposits.

General cleaning ofsolvent-soluble con-taminant (mineraloils, greases, pitch,shop soils, tar, paraf-fins, waxes, fats,fluxes, alkyd and poly.vinyl printing inks,marking compounds,silicone oils andgreases, methyl-methacrylate andstyrene).

NAVSEA SEOOO-00-EIM-160 GENERAL MAINTENANCE

Table 3-1. General Guide for Ultrasonic Cleaning

TYPICAL PRODUCTS

Surgical instruments and labo-ratory glassware, flasks, petri

dishes, syringes, ampullae,catheters, numing bottles, eye-glasses and frames, pipettes,test tubes, microscope slidesand covers, jewelry and preciousstones, technical and opticalglassware, dentures, plates,bridges, fossils, archeologicalspecimens, styrene and metha-crylate plastics, poly-plastics,hypo needles, plastic contactlenses, ceramics, precisionmetal products, quartz crystals.

Same as above, but is moreeffective on lab and opticalglass, jewelry, dental appli-ances, eyeglasses, polishingand buffing compounds,surgical instruments.

Gears, bearings, electxicrd con-tacts, micromodule wafers, typefaces, data film and tape, fil-ters, semiconductor parts,mechanical devices, glass lenses,optical parts, gyros, electroniccomponents, relays, tuningforks, bellows, electronics,ceramics, polyvinyl and poly-ethylene plastics, hermeticseals, precision metal pro-ducts, screw machine pro-ducts, connectors, technicaland optical glass, electricmotors, generators, armatures,machined parts, dressing toolsand stones, precision stamp-ings and castings, gas andwater meters, cameras, micro-scopes, sight mechanisms,gages, precision measuringinstruments, potentiometers,printed circuit boards, waximpressions.

CLEANING CHEMICAL

Concentrated water basedetergent, containingsilicat.m, phosphates,synthetic detergent, wet-ting agent.

Ammoniated concen-trated water-base deter-gent containing silicates,phosphates, wettingagents.

Chlorinated hydrocarbonsolvent.

BATH TEMPERA-TURE &

IMMERSION TIME

Room temp. to93 “c, 15 Secto 5 min.

Room temp. to93 “c, 15 Secto 5 min.

Room temp. to49 “c, 10 sec.

3-4

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GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 ROUTINE MAINTENANCEAND MAINTENANCE AIDS

Table 3-1. General Guide for Ultrasonic Cleaning - Continued

PRINCIPAL USE

General purpose picklingagent, and remover or taInish, oxide, heat-treatscale, dried blood, milk-stone.

Removes milkstone, in-vestment plaster, tempo-rary cement, zinc oxide,rust, oxides from castiron and steel, heat-treat scale and smut fromhardened steel.

Removal of corrosion oroxides on ferrous metals,salvaging engine parts(valves, betings, pumps,etc.). Precleaning ofheavy greases, shop dirt,drawing and lubricatingoils, prior to solventcleaning.

Carbon and lead depositcleaner, heavy greases ancpreservatives, buffing conpounds, drawing and lub-ricating compounds, waxand paraffin, shop dirt.

Copper cleaner, brigh-tener and tarnish remover,also to clean shop dirt,chips, grinding and cut-ting coolants, light oilsand greases.

Rust and heat-treat scalecleaner, oils, greases, buf-fing compounds, drawinglubricants, grinding oilsand coolants, cutting oilsand coolants, printingand typewriter inks.

TYPICAL PRODUCTS

Stained surgical instruments,chrome, cadmium, titanium,copper-base alloy and steel,parts and instruments, alum.inure, prepaint finishing,phospbatizing.

Precision investment castings,brewery and dairy stainlesssteel valves and process appa-ratus. Temporary dental splints,gold, acrylic, chrome crowns,inlays. Can be used on copperand alloys, ferrous metals,chrome, molybdenum, tin.

Ferrous metals, bemings,mechanical parts, diamonds,orthodontic appliances. Notto be used on aluminum,magnesium or zinc.

Aircraft, marine and auto-motive engine parts, sparkplugs, valves, pistons, cylin-ders, rings, filters, jet fuelnozzles.

Thermostats, relays, switches,jacks, connectors, brass andcopper machinin~ and castings,copper sheet and laminates.

Filaments of vacuum tubes,tungsten, steel, drawn wire androd, heat-treated metal parts.

CLEANING CHEMICAI

Concentrated water-ba.wphosphoric acid.

Powdered and inhibitedacid.

Heavy-duty alkalinesoda ash, powder.

Water-base emulsion.

Water-base, moderatelyalkaline cleaner.

Powdered alkaline.

BATH TEMPERA-TURE &

IMMERSION TIME

Room temp. to66 “c, 1 to 10min.

38°C to 82 “C,3 to 30 min.

49“C to 82 “C,1 to 10 min.

49“C to 82 ‘C,1 to 30 min.

Room temp. to60 “C, 1 to 5min.

38‘C to 82 ‘C,1 to 15 min.

ORIGINAL 3-5



Table 3-1. Genersd Guide for Ultrasonic Cleaning-Continued

BATH TEMPERA-PRINCIPAL USE TYPICAL PRODUCTS CLEANING CHEMICAL TURE &

IMMERSION TIME

Silver cleaner, brightener Thermostats, relays, switches, Water-base acid cleaner. Room temp. toand tarnish remover. jacks, connectors, silverware, 60”C, 1 to 10

sterling silver. min.

All-purpose emulsion- Pitch, ink, wax and paint, Light brown organic Room temp. tosolvent agent for one marking compounds and and chlorinated hydro- 82 “C, 30 secbath duo-cleaning of grinding compounds from carbon solvents. to 5 min.water-soluble and glass lenses, carburetors,solvent-soluble contam- engine parts.inants. Heavy greases,oils, waxes, markingcompounds, grinding,drawing, cutting oils,lubricants and coolantin any combination.

properly employed for a specific application it is ar

very fast, efficient, and reliable method of removingcontamination. Also, ultrasonic cleaning units providea degree of cleanliness that could not be obtainedpreviously by other techniques.3-2.1.3 Cleaning Solvent Hazards

The technician who smokes while usinga volatile inflammable cleaning solvent is invitingdisaster. Unfortunately, many such disasters haveoccurred. For this reason, the Navy does not permitthe use of gasoline, benzine, ether, or like substancesfor cleaning purposes. Only non-volatile solventsshafl be used to clean electrical or electronic equip-ment. In addition to the potentiaf hazard of accidentalfire, many cleaning solvents are capable of damagingthe human respiratory system in cases of prolongedinhalation. Inhibited methyl chloroform (1, 1, 1, tri-chloroethane) should be used where water compoundsare not feasible. Methyl chloroform has a thresholdof 500 parts per million (ppm) in air, whereas carbontetrachloride has a threshold of 25 ppm. The thresholdis the point above which the concentration in airbecomes dangerous. Methyl chloroform is an effectivecleaner and about as safe as can be expected whenreasonable care is exercised. Care requires plentyof ventilation and observance of fire precautions.Avoid direct inhalation of the vapor. Inhibited methylchloroform is not safe for use with a gas mask sincethe vapor displaces oxygen in the air. The followinglist of “Dos” and “Don’ts” will serve as effectivereminders to maintenance technicians who must usecleaning solvents.

3-6

1. Use a blower or canvas wind chuteto blow air into a compartment in which a cleaningsolvent is being used.

2. Open all usable port holes andplace air scoops in them.

3. Don’t work alone in a poorlyventilated compartment.

4. Place a fire extinguisher nearbyand ready for use.

5. Don’t use solvents in the presenceof any open flame since this may lead to the formationof phosgene gas, which is very poisonous.

6. Don’t use carbon tetrachloride asit is a highly toxic compound.

7. Don’t apply solvents to warm orhot equipment as this increases the toxicity hazard.

8. Don’t directly breathe the vaporof any cleaning solvent for a prolonged period.

9. Use water-based compounds in

lieu of other solvents wherever feasible.10. Wear rubber gloves to prevent

coming in direct contact with the solvent.11. Wear gloves when spraying solvent

on permissible surfaces.12. Hold the nozzle close to the

object being sprayed.13. Don’t spray cleaning solvents on

electrical windings or insulation.For additional information on the safety

precautions to be observed when using so[vents, seeNAVSHIPS Technical Manual NAVSEA 59086 -WK-STM-OOOICH-670.

ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-00-EIO.I-160 ROUTINE MAINTENANCEAND MAINTENANCE AIDS

L

3-2.1.4 Cleaning of Air FiltersSome air filters used on naval elec-

tronic equipment are designed to be installed witha film of oil on the filter element. Filters of thistype provide effective filtration with a minimumreduction of air flow. When this type of filter is usedwithout an oil coating, as is done in many ships, thefilter effectiveness is greatly reduced. The majordisadvantage of the oiled filter is in cleaning. Thisdrawback may be overcome by washing the filterelement in a standard shipboard dishwashing machine(if an air filter cleaning room or area is not provided).No special procedures are necessary, although dirtyfiIters may require two washings. The manhoursused in cleaning equipment air filters, and oilingwhen required, will he more than regained in improvedreliability of the equipment. Some of the commercialair filter adhesives (filter oils), to be used whenrequired, authorized by the Navy, are listed inTable 3-2.

Table 3-2. Typical Air Filter Adhesives

ADHESIVESDESIGNATION SUPPLIER

Airsan 1-S Air Filter CorporationMilwaukee, Wisconsin

Filterkote “M” Air Maze Corporationor “W” Cleveland, Ohio

“NCC” Visosine American Air Filter CompanyLouisville, Kentucky

WS-4530 Exon Standard Division, HumbleOil & Refining CompanyNew York, New York

Super Filter Coat Research ProductsCorporationMadison, Wisconsin

Chevron Filter Coat Standard Oil of California(applied at 71 “C) San Francisco, California

E.AC-2 Trion, IncorporatedMcKees Rocks, Pennsylvania

WARNING: Adhesives in pressurized (aerosol) spraycans are not approved for use in the Navy due to thepossibility of toxicity caused by the decompositionof the released gas.

ORIGINAL 3-7

3-2.1.5 Cleaning of Transistor Heat SinksAs the complexity of electronic equip-

ment increases, the available space for individual com-ponents has all but disappeared. Widespread use oftransistors in equipment design results in less space inwhich heat can he dissipated, thereby causing anever-increasing environmental temperature in whichthe transistor must operate. The transistor is com-pletely dependent upon its ability to absorb and dissi-pate internally generated heat while operating at theincreased temperature which it has generated. Forthis reason, heat-dissipating devices, referred to as heatsinks, are being utilized to increase the heat-dissipatingcapability of the transistor and to prevent transistorfailures due to excessive heat. Transistor heat sinks are

designed to utilize the natural methods of conduction,convection, and radiation in order to reduce the tran-sistor case and junction temperatures and therebyincrease the overall reliability of the transistor. Toobtain maximum transistor life, it is of utmost impor-tance that the transistor temperature be kept withinits design tolerance. Therefore, all transistorized equip.ments should be inspected on a routine basis to ensurethat heat sinks are free of any accumulation of dust ordirt, that air filters are clean, and that proper air flow ismaintained either from natural sources or by forced-air systems.

3-2.2 LUBRICATIONElectronic equipments which utilize

moving mechanical parts require periodic lubrication.Failure to lubricate jeopardizes the useful life ofthe mechanical part and thus precipitates a break-down of the electronic equipment. It is essentialthat maintenance personnel be thoroughly familiarwith the Lubrication requirements of the equipmentsfor which they are responsible. Proper lubrication ofthe mechanical components in electronic equipment isemphasized in technical manuals and in referencestandards books.3-2.2.1 Lubrication of Ball Bearings

Improper greasing procedures are afrequent cause of derangements to rotating electri-cal machinery provided with grease-lubricated ballbearings. The trouble is generally caused by forcingan excessive quantity of grease into the hearinghousing, with either one or both of the followingresults:

1. Grease is forced through the bear-ing housing seals and onto the windings and, in the caseof DC machines, onto the commutators where it causesdeterioration of insulation and eventually results ingrounds or short circuits.


NAVSEASEOOO-OO-ElM-160 GENERAL MAINTENANcE

Figure 3-1. Grease-Lubricated Ball Beariligs

d

2. The excessive quantity of pressureof grease in the bearing housing results in churning,increased temperatures, rapid deterioration of thegrease, and ultimate destruction of the bearing.

The following instructions apply gen-erally to all equipment except oil-lubricated bearings,synchros, and similar devices where friction must bemaintained at an absolute minimum, and equipmentfor which approved lubrication charts or other specificinstructions are furnished by the Navy.3-2.2.1.1 Greasing3-2.2 .1.1.1 Grease Cups

Motors and generators provided withbearings that should be lubricated with grease are nownormally delivered from the manufacturer with thegrease cups removed from the bearing housings andreplaced with pipe plugs. The grease cups, however, aredelivered with the onboard repair parts or special tools.It is recommended that grease cups be attached toelectric motors and generators only when the bearingsare being greased. When the grease cup is removed fromthe bearing housing after a bearing has been greased,the hole which remains should be plugged with asuitable pipe plug. When this procedure is used, thegrease cups should remain in the custody of responsiblemaintenance personnel and can be stored in the work-shop or toolroom. This procedure is particularlyadvantageous when the motors and generators main-tained by a particular group of maintenance personnelneed only relatively few different sizes of grease cups.This procedure should also be followed for motors andgenerators which have been supplied with grease cupsattached to the machine.

NOTE

Care should be taken to makesure that a grease cup is cleanbefore it is used to add greaseto a bearing, and that thepipe plug used to replace thegrease cup after greasing isalso clean.

A typical grease-lubricated bearing isshown in Figure 3-1.3-2.2 .1.1.2 Selection of Grease

The grease used for grease-lubricatedball bearings should be selected as follows:

1. Bearings which normally operateat a temperature of 194“F (90 “C) or below should belubricated with grease in accordance with MilitarySpecification MIL-G-18709.

3-8

2. Bearings which normally operate ata temperature above 194‘F (90 “C) should be lubr-icated with a silicone grease in accordance with MilitarySpecification MIL-L-15719. Machines which requirethis special grease have a caution plate stating “USEHIGH TEMPERATURE GREASE” which is attachednear the grease fitting by the manufacturer.3-2.2 .1.1.3 Adding Grease

Bearings on new machines are properlylubricated when they leave the factory. The frequencywith which grease must be added depends upon theservice of the machine and the tightness of the housingseals, and should be determined for each machine bythe engineer officer. Ordinarily, the addition of greasewill not be necessary more often than once in sixmonths. The use of excessive quantities of grease isto be avoided because it causes bearing failures. When abearing housing is too full of lubricant, the churning ofthe grease generates heat which in turn causes deteri-oration of the grease. Under these conditions the greaseseparates into oil and minute abrasive particles,becomes increasingly sticky, and tends to seal thebearing against fresh lubricant until the resultingfriction, heat, and wear cause failure of the bearing.To avoid the difficulties caused by an excessive amountof grease, add grease only when necessary.

ORIGINAL


L

‘ -

When grease is added, it should be doneas follows:

1. Wipe outside of grease fitting anddrain plug free of all dirt.

2. Remove bearing drain plug, andmake sure the passage is open by probing with a cleanscrewdriver or similar implement.

3. Remove pipe plug on top ofgrease pipe. Select proper grease cup and cleanit thoroughly. Install bottom portion of greasecup on the grease pipe. Put in the top portionof the grease cup no more grease than will halffill it.

4. Empty and clean out the recepta-cles of the grease fitting down to the neck, then fillwith clean grease.

5. Replace the grease cup and screw itdown as far as it will go.

6. Run the machine and let greaserun out of drain hole until drainage stops (normallyabout 30 minutes). Remove grease cup and replacepipe plug.

7. Replace the drain plug.8. Do not use a grease gun to lubri-

cate bearings unless there are no other means available.If a grease gun must be used, remove the drain plug inthe bearing housing while greasing and use extremecare to avoid inserting too much grease or applyingmore than just enough pressure to get the grease intothe housing.3-2.2 .1.1.4 Renewal of Grease

Without Disassemblingthe Bearing HousingRemoval of grease without at least

partial disassembly of the bearing housing is notrecommended. In any case, renewal of grease withoutat least partial disassembly of the bearing housingshould not be attempted unless the following con-ditions apply.

1. The machine is horizontal.In vertical machines, there is no adequate meansof protec t ing the windings agains t d isplacedlubricant.

2. A suitable fitting is provided foradmitting grease. If a grease-gun fitting is provided, itshould be replaced by a grease cup.

3. The drain hole on the bearinghousing is accessible. Drain pipes do not permit satis-factory escape of displaced grease, and should beremoved when renewing grease.

ORIGINAL 3-9

NOTE

The machine must be capableof being run continuouslywhile renewing grease. If themachine cannot be run con-tinuously during the greasingperiod without injuring thedriven auxilia~ or endanger-ing personnel, the bearinghousing must be disassembledas described in paragraph3-2.2 .1.1.5 to renew grease.

If the above conditions apply, the greasemay be renewed in assembled bearing housings by thefollowing method:

1. Run the machine sufficiently towarm up the bearings.

2. Wipe any dirt away from the areaaround the grease fittings.

3. Remove the drain plug and drainpipes from the drain hole in the bearing housing.

4. With a clean wire, screwdriver, orsimilar implement, clear the drain hole of all hardenedgrease.

5. Remove the grease cup and clearthe grease inlet hole of hardened grease.

6. Fill the grease cup with fresh, cleangrease, reinstall the cup and screw it down as far as itwill go. Keep the machine running continuously.

7. Repeat steps (4) and (6) above untilclean grease begins to emerge from the drain hole.

8. At this point it is important tostop inserting grease and allow the machine to rununtil no more grease comes out of the drain hole.

9. Clean any drain pipes which havebeen removed, and reinstall the pipes.

10. Install the drain plug.

NOTE

Be careful to keep grease fromreaching the electrical wind-ings. The emergence of alarge quant i ty of greasethrough the shaft extensionend of the housing indicatesexcessive leakage inside themachine.


NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANcE

Figure 3-2. Wick-Fed Ball Bearing

3-2.2 .1.1.5 Renewal of Grease with theBearing Housing DisassembledThe extent of disassembly necessary will

depend upon the construction of the bearing. For theusual construction which uses bearings with outerbearing caps, the following method should beemployed:

1. Remove the outer bearing cap afterthoroughly wiping all exterior surfaces.

2. Remove old grease from all acces-sible portions of the housing and clean these partsthoroughly. Be careful not to introduce dirt or lintinto the bearing housing.

3. Flush out the bearing cap withclean, hot (about 120 “F) kerosene, diesel fuel oil, ordry cleaning fluid (Federrd Specification P-D-680).FOI1OW this by flushing out with a light mineral oil(not heavier than SAE1O, similar to diesel lubricatingoil, N.D. Specification 14-0-13 symbol 9110).

4. Where practicable, plug all holesleading into the intenor of the machine and flush outthe complete housing with the outer bearing capremoved. Use the solvents and procedures describedin the preceding paragraph. This should not be doneon equipment where the conditions are such that thecleaning fluids may leak into the windings. In suchcases, omit this step.

5. Drain the mineral oil thoroughly;then pack housing half full with fresh, clean grease,and reinstall the outer bearing cap.3-2.2 .1.1.6 Oil-Lubricated Ball Bearings

Some electric motors and generatorsmay be equipped with oil-lubricated ball bearings.Lubrication charts or special instructions are generallyfurnished for this type of bearing and should be care-fully followed by personnel maintaining the equip-ment. In the absence of other instructions, the oil levelinside the bearing housing should be maintainedapproximately level with the 1owest point of the bear-ing inner oil ring. This will provide enough oil to 1ubn-cate the bearing for a considerable operating period,but not enough to cause churning or overheating.One cGmmon method by which the oil level is main-tained in ball bearings is the wick-feed method. In thismethod, the oil is fed from an oil cup to the insideof the bearing housing through an absorbent wick,which also filtem the oil and prevents leakage throughthe cup in the event that momentary pressure is builtup within the housing. A typical wick-fed, oil-Iubricated ball bearing is shown in Figure 3-2.3-2.2.2 Lubrication of Sleeve Bearings

When lubricating sleeve bearings, pro-ceed generally as follows:

3-1o

1. Take every precaution to keep theoil and bearings clean and free from water or foreignparticles.

2. Do not add oil while the machine isrunning. This affords an opportunity for oil mist orspray to escape from the bearing housing and be blownon the machine windings.

3. Bearings having an overflow gageshould be filled until the oil is about one-sixteenthinch from the top of the gage. If the machine is equip-ped with an oil filler gage, the gage should be tilled tothe manufacturer’s oil level mark, or (if no mark isavailable) the gage should be between two-thirds andthree-quarters full at all times. Be sure that the gageglass and piping to the gage are clean or the glass willgive false indications of the oil level. If the bearing hasneither an overflow gage nor an oil filler gage, fill itto a level such that the oil ring dips into oil to a depthof about haJf the shaft diameter.

4. When the bearing and bearinghousing are in good condition, there should be noloss of oil. If the proper oil Ievel cannot be maintainedwitbout adding oil, it is probable ‘that oil is leakingfrom the bearing. Be sure the oil sight gage connectionto bearing is tight. Much of the oil that leaks out of abearing is drawn into the machine by the cooling airand sprayed onto the windings where it causes oil-soaked dirt to collect. This condition tends to causeinsulation failure. If oil leakage is suspected, carefullyclean and chalk the shaft outside the bearing, the out-side of the bearing housing, and the parts of the rotoradjacent to the bearing. If the machine is throwing

ORIGINAL


L

oil, discoloration of the chalk will so indicate after ashort run. (This test is not dependable unless thechalked part is made perfectly clean at the beginningof the test.) If leakage is found, the labyrinth seal inthe bearing housing should be corrected to make iteffective. Another possible source of leakage is fromthe vent with which some labyrinths are provided.Make sure that any such vent is not stopped up andthat it vents into still air at atmospheric pressure, andalso where there is no current of air over the vent thatwill suck oil out of the bearing housing or oil vaporout of the vent into the machine. Such oil leakage isoften due to overfilling the bearing or trying to fillthe bearing through the vent.

5. Bearing oil should be renewed semi-annually. Drain the oil off by removing the drain plug,then flush the bearing with clean oil until the drainedoil flows clean.3-2.2.3 Types of Lubricants

The correct choice of a lubricant forelectronic equipment is important, especially if theequipment is being operated under adverse conditions.To assist in the selection of the correct lubricant, thefollowing lubrication charts are provided.

Chart 1 (Table 3-3) lists all lubricantsspecified in MIL-L-17192 (SHIPS) (NAVY), Militaryspecifications of lubncanta, and lubrication informa-tion for electronic equipment. Many electronicstechnical manuals and their associated publicationsrefer to many of these lubricants by Military Symbols.These symbols, where applicable, are added to thechart for cross-referencing.

Chart 2 (Table 3-4) provides cross--referencing between the old and new MilitarySpecification designations assigned to lubricants aslisted in Federal Supply Catalogues.

Chart 3 (Table 3-5) provides MilitarySpecification designations and Federal Stock Numbersfor those lubricants listed in electronics publicationsby the “Manufacturer’s Designation.”

Chart 4 (Table 3-6) provides a listingof those lubricants which are used in electronicsequipments and are listed in electronics publicationsbut not listed in MIL-L-17192 (SHIPS).

3-2.3 ENVIRONMENTAL EFFECTSON ELECTRONIC EQUIPMENTIt is beyond the scope of this subsection

to present all the problems encountered from environ-mental conditions, because individual methods ofinstallation and stowage of electronic equipmentsdiffer from ship to ship, and from one Naval shorestation to another. However, some of the preventive

ORIGINAL 3-11

and corrective measures that should be takenunder adverse environmental conditions, and theeffec ts on the equipment subjec ted to theseconditions, are described in the followingparagraphs.3-2.3.1 Temperature

The cooling or heating of air spacessurrounding the components of electronic equip-ment is generally accomplished and controlled byblowem, fans, hot oil and water coolers, etc., eitherto dissipate the heat generated by the equipmentcomponents, or to heat or cool the surroundingambient air. Regardless of the method employed forthe cooling or heating of spaces, if maintenance per-sonnel neglect to keep the screens, filters, fans, ducts,surface area of coolers, and equipment free fromforeign matter, the heating or cooling will be greatlyaffected, which may result in equipment damage ormalfunction caused by improper temperature control.Extremely low temperature may cause brittleness incertain types of metals, and loss of flexibility inrubber, insulation, and similar materials. Extremelyhigh temperature may cause deformation and deteri-oration of terminal boards, seals, insulation, andheat-sensitive devices. Rapid changes of temperaturemay be especirdly damaging to certain types of elec-tronic components.3-2.3.2 Humidity

High humidity, the “arch enemy” ofelectronic equipment, with its resultant damage toequipment components from condensation and fungusgrowth under conditions of both high salt-laden moistair and high temperature, is normally found in tropicalclimates. In this case, adequate ventilation of theequipment is of the utmost importance to protect theequipment components from entrapped moisture andextremely high operating temperatures. To overcomeany adverse effecta on electronic equipments, mcwi-mum and minimum temperature gradients should becontrolled by one of the cooling or heating mediumsprovided. In many cases, critical electronic componentsare encapsulated, potted, or sealed to protect themfrom the detrimental effects of moisture and temper-ature variations. However, sealing the component .does not completely eliminate the problem of high-humidity conditions because the seals sometimesmust be broken for maintenance or repair work. Thereis also the possibility that the maintenance technicianwill not always have the suitable sealing compoundson hand to repair or replace sealed components. Wherethis condition exists, except in cases of emergency, therepair or replacement of sealed components shouldnot be performed in the field.

ROUTINE MAINTENANCE NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCEAND MAINTENANCE AIDS

Table 3-3. Standard Navy Lubricants

SPECIFICATION;

VV-P-236Petrolatum,Technical

I

IVV-I-530Insulating OilElectrical

I

P-D-680 DryCleaning Solvent

I MIL-G-23827] Grease, AircraftI and Instrument

IIII

MIL-G-81322Grease, Aircraft

UNIT OFISSUE

1 lb. can5 lb. can

1 qt. can1 gal. can5 gal. pail55 gal. drun

5 gal. pail

1 oz. tubei oz. tube3 oz. tube1 lb. can5 lb. can35 lb. pail

; lb. can15 lb. pail

STOCK NUMBER

9G9150-250-09269G9150-25043933

9G9160-685-09129G9160-611-20009G9160-685-09139G9160-685-0914

9G6850-274-5421

9G9150-985-72439G9150-985-72449G9150-985-72459G9150-985-72469G9150-985-72479G9150-985-7248

9G9150-OO-190-08939G9150-OO-190-0907

MILITARSYMBOL

PET

;D-2

11A

COMMERCIADESIGNATION

Amber Petro-latum U.S.P.

%ade I

GENERAL USE

For use as a light grade oflubricating grease but notrecommended for use asa lubricant in heavilyloaded or hot runningbearings. It may be usedas a constituent in cer-tain types of rust preven-tive compounds.

Dielectric strength 30,000volts, with exception of9G9160-082-2428 whichis 40,000 volts. Used inoil-immersed transform-ers, oil switches, and oilcircuit breakers.

For genemd cleaning ofair filters, electronicequipment, and othergeneral purpose cleanup.

In ball, roller, needlebearings, gears and slid-ing and rolling surfacesof such equipment as in-struments, cameras,electronic gear and air-craft control systems.Particularly suitable foraquipment which must~perate at both very lowmd very higb tempera-tures for short periods.Does not contain extremepressure or special anti-wear additives. It is de-structive to paint, naturrdrubber, and neoprene.

For lubrication and pro-%ction against corrosion>f plain ball and roller~earings, and preserva-tion of threads on ammu.Iitions.

3-12 ORIGINAL

b

L


l--SPECIFICATIO1NUMBER AND

TITLE

MIL-L-17331Lubricating OilSteam Turbine

II

III

MIL-G-18709Grease, Ball andRoller Bearing

MIL-L-2105Lubrication OilGear

MIL-L-6085Lubricating OilInstrument

MIL-L-6086Lubricating OilGear

UNIT OFISSUE

5 grd.55 gal.

3 oz. tube1 lb. can5 lb. can35 lb. pail

i gal.1 gal.55 gal.55 gal.

1 1/2 OZ. btl.I oz. can1 qt.

1 grd. can1 pt. can1 gal. can5 grd. drum

Table 3-3. Standard Navy Lubricants - Continued

STOCK NUMBER

9G9150-235-90619G9150-235-9062

9G9150-753-46509G9150-526-42059G9150-663-97959G9150-249-0908

9G9150-577-54819G9150-754-26359G9150-577-58439G9150-035-5394

9G9150-664-65189G9150-257-54493G9150-223-4129

9G9150-265-94179G9150-240-22359G9150-223-41309G9150-223-4116

MILITAR!SYMBOL

2190 TEP

BR

GO-75GO-90GO-75GO-90

OAI

Grade LGrade M


COMMERCIALDESIGNATION

Andok B orNebula EP-1Grade III

SAE 75SAE 90SAE 75SAE 90

-lo w--20 w-

GENERAL USE

In main turbines andgears, auxiliary turbineinstallation, certainhydraulic equipmentgeneral mechanicallubrication, andair compressors.

For ball and rollerbearings operatingat medium speedsand temperaturerange 125° F to200”F.

For lubrication ofautomotive gear units,heavy duty industrial-type enclosed gearunits, steering gears,and fluid-lubricateduniversal joints ofautomotive equipment.

For aircraft instru-ments, electronic equip-or where a low evapora-tion oil is required forboth high and lowtemperature application,and where oxidationand corrosion resistanceare desirable. Destruc-tive to paint, neopreneand rubber.

For use under extremelylow temperature, mildextreme pressure-typeoil with load carryingadditive. General usein aircraft gearmechanisms, exclusiveof engines.

ORIGINAL 3-13


Table 3-3. Standard Navy Lubricants - Continued

L=SPECIFICATIONNUMBER AND

TITLE

MIL-L-9000Lubricating OilInternal Com-bustion

MIL-L-17331 &MIL-L-17672Lubricating OilGeneral Purpose

UNIT OFISSUE

5 gal.55 gal.5 gal.55 gal.5 gal.55 gal.

1 pt.5 gal.5 gal.55 gal.

STOCK NUMBER

9G9150-231-90379G9150-231-90309G9150-188-98589G9150-189-67299G9150-181-82299G9150-181-8097

9G9150-985-72309G9150-985-41379G9150-235-90619G9150-235-9062

MILITARYSYMBOL

9110

9170

9250

207521102190

COMMERCIALDESIGNATION

SAE 10

SAE 20

SAE 30

SAE 20WSAE 10SAE 30

Table 3-4. Old and New Specification Designations

GENERAL USE

For internal-combustionengines operating undernormal load and temper.ature conditions.

For all applications whichrequire other than speciallubricants, and which aresubject to normal varia-tion between ambientand operating tempera-ture. Use in lieu ofMIL-L-6085 when oil willbe in contact with neo-prene.

OLD MILITARY NEW MILITARYSPECIFICATION SPECIFICATION

REFERENCE

14-P-1 VV-P-236 See Table 3-314-L-3 MIL-G-18709 See Table 3-314-G-1O MIL-G-16908 See Table 3-314-L-11 VV-G-632 See Table 3-614-0-12 VV-1-530 See Table 3-314-0-13 MIL-L-9000 See Table 3-314-0-15 MIL-L-17331 See Table 3-314-0-20 MIL-L-6085 See Table 3-3AN-O-6a MIL-L-7870 See Table 3-6KS 7470 MIL-L-17672 See Table 3-6MIL-S-16067 P-D-680 See Table 3-3VV-O-401 VV-I-530 See Table 3-3P-S-661 P-D-680 See Table 3-3MIL-G-3545 MIL-G-81322 See Table 3-6MIL-G-3278 MIL-G-23827 See Table 3-3

d

4

3-14 ORIGINAL

4

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 ROUTINE MAINTENANCE

L


Table 3-5. Manufacturer’s Designations

MANUFACTURER MILITARY UNIT ORDESIGNATION SPECIFICATION ISSUE STOCK NUMBER

Lubri-Plate No. 105 None 2 oz. 9G9150-291-9088Lubri-Plate No. 110 None 1 lb. 9G9150-223-4003Molykote “G” None 1 lb. 9G9150-985-7317Molykote M-77 None 1 lb. 9G9150-985-7317Stoddrwd Solvent P-D-680 See Table 2-3

140-F P-D-680 See Table 2-3MOS, Lube-Powder MIL-M-7866 10 oz.GE 10C VV-I-530 See Table 2-3GE SS4005 MIL-S-8660 1 oz. 9G6850-880-7616Dow-Corning DC-4 MIL-S-8660 1 oz. 9G6850-880-7616McLube MOS2-210

(formerly MOS2-200) None As Requested *

McLube MOS2-1118 None As Requested *

Therrnotex qf~~ None 1 lb. 9G9150-082-2650

* Must be ordered from McGee Chemical Co., Inc., 8000 West Chester Pike, UPper D~by, pa.

Table 3-6. Lubricants Used in Electronics Equipments But Not Listed in MIL-L-17192D (Navy)(Lubrication Information of Electronic Equipment)

SPECIFICATIONNUMBER AND

TITLE

51-F-23Hydraulic Fluid

ASTM D-3699Kerosene

MIL-L-7870Lubrication OilGeneral Purpose

VV-G-632General PurposeGrease

MIL-G-23827Grease Aircraft

ORIGINAL

UNIT OFISSUE

5 gal.55 gal.

5 gal.

4 oz.1 qt.1 gal.

35 lb.100 lb.

1 lb.

STOCK NUMBER

9G9150-261-83179G9150-261-8318

9G9140-242-6749

9G9150-542-14309G9150-263-34909G9150-273-2397

9G9150-190-09079G9150-235-5551

9G9150-985-7246

MILITARYSYMBOL

K

OGP

CG-1

3-15

20MMERCIALDESIGNATION GENERAL USE

Used in connection withthe hydraulic transmis-sion of power. For use withSynthetic Serd.

General uses such as acleaner for machinery ortools.

Specially designed for usewhere an oil of low evap-oration, possessing rust-protective properties, isdesired.

Automotive chassis, suit-able for lubrication ofmachinery equipped withpressure grease fitting.

Used in rolling and slidingsurfaces having very lowmotivating power.


Table 3-6. Lubricants Used in Electronics Equipments But Not Listed in MIL-L-17192D (Navy)(Lubrication Information of Electronic Equipment) - Continued

SPECIFICATIONNUMBER AND

TITLE

MIL-G-81322Grease Aircraft

MIL-C-1109OCleaningCompound

MIL-L-17672Lubrication OilGeneral Purpose

VV-L-7.51Lubrication Oil

UNIT OFISSUE

1 lb.

5 gal.55 gal.

1 gal.55 gal.

35 lb.35 lb.

STOCK NUMBER

9G9150-233-4003

9G6850-224-66659G6850-224-6666

9G9150-753-47999G9150-582-5480

9G9150-246-32629G9150-246-3267

MILITARYSYMBOL

211 O-H

CW-lACW-lB

30MMERCIALDESIGNATION GENERAL USE

Used in antifriction bear-ings operating at highspeeds and high temper-atures.

Used as a solvent forcleaning grease and oils.

Used in steam turbines,hydraulic systems, watergenerators and bydraulicturbine governors.

Cold weather.Warm weather.Hot weather.Used for lubricating chain,wire rope, exposed gears.

3-2.3.3 StorageWhen electronic equipment and com-

ponent parts are to be stored, or when they mustremain in an inoperative condition for a considerablelength of time, additional preventive measures mustbe taken to prevent detrimental effects from environ-mental conditions. New or repaired modular assem-blies and parts are received in accordance with theapplicable packaging specification. When the outerbulky casing (crate or carton with its Kimpak, Reliso-Pak or similar material) is removed, the unit (or units)remains packaged in a water-vaporproof bag. Thispackage should be stored intact until drawn for use asa replacement item by the maintenance technician.3-2.3.4 Standby Equipment

Equipment that is to remain idle anddeenergized for a considerable length of time shouldhave its space heaters (if provided) turned ON to keepthe insulation and equipment dry. If space heaters arenot provided for the equipment, electric lamp bulbsor a portable electric heater as a temporary measurecan be placed within or near the equipment. This isespecially important in humid or cold climates. Heatersshould cycle/go off when main power is secured.

3-16

3-2.3.5 Corrosive AtmosphereA corrosive atmosphere can cause

serious damage to unprotected electronic equipment.For this reason, the maintenance technician should becognizant of the harmful effects of all corrosive ele-ments. He must be especially aware of the effects pro-duced by salt sp~y or salt-impregnated air. To preventcorrosive effects, a regular periodic cleaning scheduleshould be established. This schedule should includedusting and cleaning, lubrication of moving parts, andthe application of approved solvents or wetting agentsto remove any accumulation of foreign matter, such assoil, dust, dirt, oil film, salt-impregnation, etc. Inaddition, all access doors and panels should be fastenedsecurely and in place when no maintenance work isbeing performed on the equipment.3-2.3.6 Barometric Pressure Effects

Electronic equipment installed in air-craft or submarines is often subjected to severe changesin barometric pressure. To overcome any adverseeffects on the equipment, pressurization of individualcomponents by use of pressurized chambers is oftenemployed. These components are hermetically sealedto prevent variations in barometric pressure, and are

ORIGINAL


Table 3-7. Soldering Iron Tips(Standard Plug Tip Soldering Iron)

DIAMETER(INCH)

A*2 PERCENT

1/43/81/25/87/8

LENGTHEXTENDINGFROM SHELL

(INCH)B

(rein)

1-1/4222-1/42-1/4

HEATING TIME(MINUTES)

(max)

2-1/244-1/256

Table 3-8. Pencil Iron Tips(Type III, Style “A”, Pencil Plug Tip Iron)

LENGTHDIAME- EXTENDING

TER FROM SHELLA (INCH)*2 B

PERCENT (rein)

1/8 7/81/4 1-1/4

SHELLASSEMBLY HEATINGDIAMETER TIME

(INCH) (MINUTES)c (max)

(max)—.

3/8 1-1/21/2 2

generally classified as throwawayitems. Therefore, the maintenancenot attempt to repair such items.

or nonrepairabletechnician should

3-2.3.7 Vibration and ShockVibration effects are directly related

to the resonant mechanical frequency of the equip-ment concerned. Vibration caused by loosening ofparts, or relative motion between parts, can produceobjectionable operating conditions such as noise,intermittent circuit malfunctions, short circuits, com-ponent electrical overload or burnout, and equipmentfailure. Mechanical shock caused by impacts or highacceleration or deceleration can result in extensivedamage to, or derangement of, the electrical equip-ment. In order to maintain and minimize the detri-mental effecta from shock or vibration, shock-mounting and anti-vibration devices of various typesand sizes are being employed in shipboard installationsto isolate the component-s and equipments from theirmountings. Each device has its own place in the fieldof isolation; the selection of isolators depends uponspecialized requirements and tolerance to the environ-mental conditions in which they must operate. Shock-mount and anti-vibration devices are relatively simplein their design and construction and require littlemaintenance. Conditions of service and age and thecondition of the equipment differ from ship-to-ship.Consequently, it is impracticable to provide a rigidschedule of inspections and tests, However, certaingeneral requirements and precautions must be takenand observed to ensure that the mounting clips, shock-mounts, ground straps, and associated hardware aresecured and are in place. Precautions must be takento ensure that paint, oil, solvents, and other types oforganic material are not applied to or allowed tocome in contact with the resilient surface area of ashock-mount. If allowed to do so, this will result inloss of resiliency, deterioration, and premature failureof the resilient member of the shock-mount.

3-3 MAINTENANCE AIDS

Proper care and maintenance of elec-tronics equipment are dependent in large measure onthe quality and condition of the tools with which theelectronics technician performs his duties. It is impor-tant that the technician know the capabilities of eachof his tools and the techniques by which each tool maybe used. It is also important that the technician befamiliar with methods for the care of his tools. Goodworkmanship depends not only on the skill of thetechnician but also on the quality of his tools; good,clean tools aid good, clean work. This section willdeal with the tools most likely to be used in electronic

ORIGINAL 3 - 1

maintenance and repair; their various usages will bediscussed with regard to safety of personnel and propermaintenance and stowage of the took..

3-3.1 SOLDERING TOOLSThree groups of soldering tools are used

in electronic maintenance. Each group is designed to beused for the particular job at hand, such as heavy duty,light or generaJ duty, and intricate soldering duty onsuch items as semiconductors, printed circuit boards,and modular assemblies used in electronic equipment.3-3.1.1 Soldering Irons

Soldering irons are used for heavy dutytypes of electronic work such as unsoldering heavyconnections and tinning surface. There are two types ofsuch irons: a plug tip, and a thermostatically controlledscrew-in tip. These irons are shown in Figure 3-3 andthe tips used with each type iron are listed in Table 3-7.

3-3.1.2 Pencil IronsPencil irons are used for general or light

duty work or for intricate work. There are two styles ofpencil irons: a plug tip, and a screw-in tip with a self-contained heating element. The pencil irons are shown inFigure 3-3; the tips foreach style aregiven in Table 3-8.

7



8P L U G T I P

~SET SCREW

I

* INTERCHANGEABLE TIP WITH HEATING UNIT

‘HREAfi++ ‘HREp~~’13TAPER L 3

No. OTip No. 1 TipTAPER

+@ ~i TAPER

- 5,

THREAD

‘HEX Ip&

2:* ~[,j,, j?+!

10.2 T i p No. 3 Tip No. 4 Tip

INTERCHANGEABLE TIPS

A

s

c

TNREAD-IN UNITSFOR SUS-MINIATURE

SOLOERING

— 1

Figure 3-3. Types bf Soldering Irons and Tips


3-3.1.3 Soldering GunsSoldering guns are used for general pur-

pose or light work when virtually instantaneous heat isrequired for just a short time. There are two types ofsuch guns. Type I utilizes a transformer and a solidcopper wire tip; Type II does not have the transformerand uses a straight, solid copper, screw-in tip. The twotypes of guns are shown in Figure 3-4; the tips for eachtype gun are listed in Table 3-9.

3-3.2 SPECIAL HAND TOOLSFor successful installation, repair, and

maintenance of electronic equipment, the electronicstechnician must have not only a high degree of mech-anical skill and dexterity, but also a thorough know-ledge of the proper selection and use of tools. Mostfaults in electronic maintenance cannot be correctedwithout the use of tools. The ease and efficiency withwhich a repair can be made is often a direct functionof the tool selected to perform a given task. In the per-formance of their duties, maintenance personnelshould be provided with, or have access to, at least oneeach of the basic tools listed in the Electronics ToolAllowance List, and should also have access to thespecial hand took discussed in the following sub-sections.3-3.2.1 Punches

Punches (shown in Figure 3-5) oftenprove useful in electronics work. Punches usually pro-vided in the electronics shop are the center punch,starting punch, pin punch, aligning punch, gasketpunch, and various types of chassis punches.

1. The center punch is used to make apunch mark for starting a drill. The point of this punchis carefully ground to an angle of 60 degrees, which isthe same as the angle of a standard twist drill. Drillswill start more quickly and have less tendency towander if they are started in a punched hole.

2. The starting punch is used to knockout rivets after the heads have been cut off. It is alsoused to start driving out straight and tapered pinsbecause it can withstand the heavy hammer blowsnecessary to break the pin loose and start it moving.This punch is made with a long, gentle taper extendingfrom the tip to the body of the punch.

3. The pin punch is made with astraight shank and is used to follow-up on the jobrequiring a starting punch. After a pin has been par-tially driven out with a starting punch, which is limitedin use because of its increasing taper, the pin punchwith its slim shank is used to finish the job. The pinpunch should never be used as a starting punch becausea hard blow may cause the slim shank to bend or

ORIGINAL 3-19

break. The largest size pin punch that will fit into

the hole should always be used. The pin punchshould never be struck with a glancing blow as itmay break the punch and broken pin punches maybe difficult to remove from the hole.

4. The aligning punch is generallyfrom 12 to 16 inches in length and has a long taper.This punch is used for moving or shifting plates orparts so that corresponding holes will line up. It shouldnever be used as a pry bar.

5. The hollow shank gasket punch isused for cutting holes in gaskets and similar materirds.The cutting end is tapered to a sharp cutting edge tomake clean, uniform holes. The material to be cutshould be placed on a soft background such as lead orhardwood so that the cutting edge will not be damaged.

6. The scratch awl, or metal scribe,is also in this category of tools. It is used to marksoft metals and can serve as an alignment tool.Punches are made of tool steel, tempered and hardenedat the point. A punch should never be used towork on extremely hard metals or remove bolts byforce because its point will be dulled.

7. The chassis punch provides a quickmethod of cutting round, round-keyed, square, or “D”shaped holes in steel up to 16-gauge in thickness.These punches are made of tool steel and are operatedby screw action to provide clean-cut holes. The roundchassis punches are available in sizes ranging from 1/2to 3 inches in diameter. To use the chassis punch, ahole slightly larger than the punch screw size must bedrilled in the material at the center of the hole to becut. The punch must then be disassembled. The cuttersection has two cutting edges located symmetricallyfor balance and is threaded to receive the bolt (punchscrew). The bolt is inserted through the die section andthen through the drilled hole in the material. The boltis then screwed into the cutter until it is “finger tight.”A wrench of the proper size to fit the bolt headis then used to turn the bolt clockwise until the cutterhas completely cu. through the material. After thehole is made, the punch must be disassembled againand the metal. removed from the die. The edge of thehole in the material should be smoothed and deburredwith a half-round file.3-3.2.2 Taps

The tap is a tool employed for cuttingthreads to receive a machine screw. These threads arecut into the sides of a hole which has been drilled forthe root (minor diameter) of the screw. The tap isnumbered the same as the screw; i.e., if a No. 5-40screw is to be used, a No. 5-40 tap is used to cut thethreads in the sides of the hole. There are three styles


d

,.,,. -

“1 YPF. I

T“ YPE I I

Figure 3-4. Soldering Guns

3-20 ORIGINAL


Table 3-9. Soldering Gun Tips

WEIGHT A B c DCLASS DUTY WITHOUT TIP OVERALL HEIGHT WIDTH

CORD LENGTH LENGTH (INCHES) (INCHES)(OUNCES) (INCHES) (INCHES)

(Type I Soldering Guns)

1 Heavy 50 5-7/8 12 ‘7 32 Medium 48 5-3/8 12 7 33 Light 40 5-3/8 12 7 3

(Type II Soldering Guns)

1 Heavy 50 6-1/2 12 6 1-1/22 Medium 16 6 10 5-1/2 1-3/83 Light 10 5 9 5 1-1/4

of taps: the taper, the plug, and the bottoming tap.All three styles will cut the same size thread requiredbut the style selected is determined by the situationand/or depth requirement. The taper tap diameter willgradually increase in size and may be used when thework permits the tap to be run entirely through thehole. The plug tap, whose first few threads are cham-fered, will produce threads afmost to the bottom ofa hole. When threads are required to the very bottomof a hole, the plug tap is used and then removed andthe bottoming tap is used since it will cut through tothe bottom of the hole. The tap is held in a specialholder known as the tap wrench. There is the straighthandle type and the T-handle type wrench. The threestyles of taps and the two types of tap wrenches areshown in Figure 3-6.3 - 3 . 2 . 3 Dies

The die is a thread-cutting device usedto cut threads on outaide surfaces, whereas taps areused to cut threads on inside surfaces. Dies are madeto cut right-hand or left-hand threads and are found ina variety of forms. There are adjustable round splitdies for screw and bolt threading; square solid diesfor hose fittings; hexagon solid dies for dressing overbruised or rusty threads; and various types for pipethreading. The die-holder is called a die stock. A dieand die stock are shown in Figww 3-6.3 - 3 . 2 . 4 Reamers

A reamer is used to make a true circularhole, or to enlarge a hole. Unless a hole has been drilledperfectly true, it will be slightfy eccentric or slightlyoversize. There are various styles of reamers such as thesolid spiral, solid straight and the tapered hand reamer

ORIGINAL 3-21

used in sheet metal work for enlarging or correctingsmall holes to the desired size. The various styles andtypes of reamers are shown in Figure 3-6.3 - 3 . 2 . 5 Countersinks

A countersink is a reamer which is usedto bevel the edges of a hole. It is generally used in theelectronics maintenance shop to countersink screw holesso that flat-head machine screws will be flush with thechassis surface. The countersink is found in many anglesand the one selected should have the same angfe as thehead of the flat-head machine screw being used. In anemergency, a drill twice the diameter of the screw holemay be used. A countersink is shown in Figure 3-6.3-3.2.6 Rotary Cutting Tools

Rotary cutting tools commonly used inelectronics work (Figure 3-7) are: the circle cutter, therotary hacksaw, and the caxbide cutter. These tools areused to cut large circular holes from 1 to 5-1/2 inchesin diameter in materiaf up to 1 inch in thickness.3-3.2.6.1 Circle Cutter

The circle cutter (commonly crdleda “fly-cutter”) is used in a drill press to cut large holes.It consists of a body provided with a square taperedbitstock shank, fitted with a replaceable l/4-inchstraight diameter shank twist drill and an adjustableround bar carrying a renewable cutter bit. To use thecircle cutter, determine the size of hole to be cut anduse the following procedure:

1. Adjust the round cross-arm so thatthe distance from the point of the guide bit to thetip of the cutter bit is one-half the diameter of thehole to be cut. Securely tighten the cross-arm lockingscrew in the cutter body.



CENTER PUNCH

., ..,. . . . . . . . . . . . . . . . . . . . . . . . . . .............,..,.;...,,.,,,,, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,.,:,,,“’’ .’,’ . ’., . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .,,:.:.:.:.:,:,,,:,:.:,:,,,,,:::::, .,:,.,.:.:.,.:,:. :. :.:.:. : .: .,.,..,,,:,:,; ::,,,:.,,.:::.,, ,., : .,.,.:,:.:.,.,, ..:.:. ,.:, ,, :.:.:......,...,.,.,.,.,

STARTING PUNCH

PIN PUNCH

ALIGNING PUNCH

“.’.:..,..:.:.:,..:::. . :::::,::::::,::,,:::.::,.:.:. ,,:.:,: ,::,,:.:.:,:,,,,.,,,,,,

SCRATCH AWL

CHASSIS PUNCH

Figure 3-5. Punches

3-22

d

ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 ROUTINE MAINTENANcEAND MAINTENANcE AIDS

TAPER HAND TAP

PLUG HAND TAP

.

BOTTO141NG HAND TAP

SOLID SPIRAL

SOL lO STRAIGHT

)

ADJUSTABLE TAP WRENCH

wT-HANDLED TAP WRENCH

DIE AND DIE STOCK

EXPANSION

ADJUSTABLE

HAND REAt4ERS

1

COUNTERSINK

TAPERED HAND REAMER

Figure3$. Taps, Dies, and Reamem

ORIGINAL 3-23


ROTARY HACKSAW


CARBIDE ROTARY CUTTERS

Figure 3-7. Rotary Cutting Tools

2. Adjust the guide bit so that itextends approximately l/2-inch beyond the tip of thecutter bit and then tighten the guide bit locking screwin the cutter body.

3. Place the shank of the circle cutterin the chuck of the drill press.

4. Clamp the work on a wooden blockwhich will support the entire area of the circle to becut. Tighten the clamps to ensure that work will notrotate with the cutter.

5. Center-punch the center of thecircle to be cut.

6. Place the tip of the guide bit on thepunch mark and commence drilling the hole.

7. Continually apply pressure until thecutter bit has cut through the material.

3-24

3-3.2.6.2 HacksawsThe rotary hacksaw, shown in Figure

3-7, can be used to cut large holes through any machin-able material up to 1 inch in thickness. The rotaryhacksaw is for use in drill presses or portable electrichand drills. It has a high-speed steel cutting edge whichis electrically welded to a tough, alloy steel body; ithas a high-speed steel pilot drill, heavy hexagonafshanked arbors and a sufficient set for deep drilling.Rotary hacksaws are self-aligning, as the larger diam-eter saws float on their arbors and are driven by doubledrive pins. The material should be center-punched forthe pilot drill and clamped in a vise or on the dnllpresstable. When using an electric hand drill, the drill shouldhave a no-load speed of not more than 1500 r/rein.3-3.2.6.3 Carbide Cutters

Carbide cutters, shown in Figure 3-7,are rotary cutting tools made of solid carbide and areused in drill presses, portable electric hand drills, andflexible shaft tools for grinding, filing, burring, counter-sinking and cutting metal. They are available in variouslengths and sizes with both 1/8- and l/4-inch diametershanks.3-3.2.7 Wire and Thread Gauges

Wire and thread gauges are used todetermine the size of wire and the number of threadsper inch on a screw, respectively. There are varioustypes and styles of wire and thread gauges in usetoday. The most common types of these gauges areshown in Figure 3-8.3-3.2.7.1 Wire Gauges

The wire gauge is used to determinethe size of a wire. It is usually circular in shape withnotches around its edge and an adjacent number. Touse this gauge, insert the wire into the smaflest notchthat will accept it and note the corresponding number.3-3.2.7.2 Thread Gauges

The thread gauge is used to determinethe number of threads per inch of a screw. It consistsof a number of leaves attached to a handle. The leavesare accurately machined on one edge to conform tothe standards of the cross-sectional shape of the screwthreads they are made to measure. The threads perinch of a screw are determined by placing the screwagainst each leaf of the gauge until the threads of thescrew exactly match those of the leaf. The markingsof this leaf indicate the number of threads per inch.3-3.2.8 Wire Strippers

When preparing wires for terminationsand connections, the removal of the insulation withoutdamaging the conductor is of prime importance. It hasbeen established by experience that the only practicalway of preventing damage to conductors when removing

ORIGINAL

GENERAL MAINTENANCE

WIRE GAUGE


SCREW THREAD GAUGE

Figure 3-8. Wire and Thread Gauges

ROUTINE MAINTENANcEAND MAINTENANcE AIDS

Figure 3-9. Wire Strippers

Figure 3-10. Tube Puller

insulation from wires is by using tools designed for thispurpose. Two types of wire stnppem are shown inFigure 3-9. The first type is the simpler of the two, andis especially useful for stripping insulation in tightquarters. To use it, place the end of the lead into thecutting groove of the stripper; hold the wire in onehand, the stripper in the other hand and pull down-wards, away from the cutting edges of the groove. Thesecond type is used when stripping many wires. Whenusing this type of wire stripper, place the wire into thecorrect groove to avoid cutting the end off the conduc-tor instead of stripping off the insulation.3-3.2.9 Tube Puller

The tube puller shown in Figure 3-10is used to pull a hot tube without waiting for it tocool down. The puller holds on to the tube by suc-tion. To use it, push the button, seat the puller on thetube, release the button, and pull the tube.

ORIGINAL 3-25

3-3.3 REFERENCE PUBLICATIC)NSVarious publications, some of which

are discussed below, are available for guidance inmaintenance work, or for reference and study by



electronics personnel. Some of these publications areas vital to intelligent maintenance as is test equipment.In general, publications are available from the U.S.Naval Publication and Forms Center, Philadelphia.However, before requisitioning such material, consider-ation should be given to the equipment installed, themission of the ship or activity, the purpose of anddistribution policy for the individual publications, andthe available stowage space. Because it is essentialthat reference material be as current and accurate aspossible, publication changes and corrections should beentered as they become available. For example, if thecurrent issue of the EIB corrects information appear-ing in an earlier issue, the earlier issue should bechanged. If the change affects other publications(techniczd manual, field change bulletin, and partsallowance list, for instance), these also must be cor-rected. The changes must be legible and accurate. Ifno page is furnished for recording completed changes,some method for recording these changes should bedevised. One method is to make notes in the marginof the new material to indicate the publications inwhich the change has been entered. By assigning tospecific individuals the responsibility for making allchanges in designated publications, and by checkingtheir entries from time to time, the ElectronicsOfficer will do much toward eliminating the possibilityof his crew using incorrect repair information. In orderthat an activity’s file of publications may be kept upto date, current issues of the Naval Ships TechnicrdNews, the EIB, and the Index of Forms andPublications (NAVSUP 2002) should be examined forinformation on the availability of handbooks, finaltechnical manuals, revision supplements, and changespertaining to the equipment on board.3-3.3.1 Naval Ships Technical Manual

The Naval Ships Technical Manual is themost complete and authoritative reference availableon NAVSEA equipment. This manual is issued as aninformative and comprehensive guidance to Navalpersonnel, afloat and ashore, who are responsible for,or engaged in, the installation, operation, maintenance,and repair of equipment under cognizance of theNaval Sea Systems Command.3-3.3.1.1 Scope

The manual contains administrative andtechnical instructions not included in the U.S. NavyRegulations or other publications of higher authoritybut which are deemed necessary for a clear understand-ing of the requirements of the technical work andequipment under the cognizance of the Naval SeaSystems Command. The data and instructions in the

3-26

manual are in accordance with what is consideredthe best engineering practices for operation, mainte-nance, testing, and reliability of the equipment and forthe safety of the personnel concerned. Chapter 400 ofthe manual, titled “Electronics,” is required reading forelectronics personnel. This chapter rdso lists otherchapters containing information of value to electronicspersonnel. The instructions and data contained in thismanual do not intrude on or interfere with the internalorganization of a ship or with prerogatives of the oper-ational commander. In order to make the instructionsclear, brief descriptions and illustrations of type unitsor outstanding examples of subtypes in the same classhave been included. However, for complete informat-ion of design details, operation, adjustment, andcare of equipment, the specific equipment’s technicalmanual must be consulted.3-3-3.1.2 Distribution

Each chapter of the manual is preparedas a separate pamphlet so that individual chaptersmay be issued to Naval vessels or other Naval activitiesfor use in the instruction of Naval personnel. Copies ofindividual chapters shall be requisitioned directly fromthe U.S. Naval Publications and Forms Center,Philadelphia, Pa. 19120, in accordance with NAVSUPPublication 2002, using DD Form 1348 (MILSTRIP ).Specific requests from U.S. Naval Activities for theindividual chaptem are required. Requisitions fromother Departments of Defense, other Governmentagencies, and foreign nationals for the subject manualstill require Command approval and are to be for-warded to the Naval Sea Systems Command.3-3.3.2 Equipment Technical Manual

The equipment technical manuals whichare presently being prepared in accordance withMIL-M-15071( )(Type 11) provide all the informationnecessary to install, operate, and maintain the equip-ment. Unless otherwise specified, the maintenanceinformation applies to organizational, intermediateand depot-level maintenance. In addition, the informat-ion fulfills requirements for logistic, engineering andtraining support of the equipment. The manual util-izes cross-referencing techniques to reduce the timerequired to locate maintenance data and to simplifythe troubleshooting process. It is intended that thetechnician shall never be dead-ended in access to tech-nical manual information during maintenance andtroubleshooting actions. Each equipment manualcontains eight specific chaptem of data. The chaptersmay be arranged sequentially in one volume or conven-iently arranged in multiple volumes. The contents ofeach chapter are described as follows.

ORIGINAL


CHAPTER 1 – GENERAL INFORMATION ANDSAFETY PRECAUTIONS

All safety precautions necessary for theprotection of personnel, the ship and the subjectequipment are emphasized prior to the general contentof this chapter. Statements regarding the WARNINGSand CAUTIONS applicable to all procedures presentedin the manual are included or cross-referenced as asafety summary. The generaJ content of this chapteris such that command level, supervisory personnel andother users having a general interest in the equipmentcan determine the purpose, physical, functional andoperational characteristics of the equipment andvarious equipment configurations. An introductionto the manual provides an explanation of the purpose,scope and applicability of the manual. Illustrationsof each unit are provided for physical identificationand their relationship to other units. Tabular listingsinclude all equipment, accessories, and documentssupplied and/or required for use with the equipment.

CHAPTER 2 – OPERATION

This chapter contains all the proceduresnecessary to enable operating personnel to efficientlyand effectively use the equipment. These includeroutine and emergency operating instructions, safetyprecautions, operating limits, complete starting (tum-on) and stopping (turn-off) procedures, includingemergency turn-off, and any instructions required bythe operating personnel to prepare the equipment foruse. Where operating procedures are to be performedto a specific sequence, step-by-step procedures aregiven; initial safety requirements and connections ofaccessory equipment are also given. Tables and chartsare provided for the presentation of operating instruc-tions for different modes of operation. Waxnings andcautions for conditions that may create hazards arelocated appropriately. Instruction for operator’s main-tenance and the use of test equipment incorporatedin the equipment is also included. Illustrations whichshow the location of controls, checkpoints, andadjustments (with normal indications listed) areincluded to facilitate use and understanding of theprocedures.

CHAPTER 3 – FUNCTIONAL DESCRIPTION

This chapter provides the technicianwith an understanding of the circuit theory andfunctional operation necessary for efficient trouble-shooting and repair of the equipment. Included is a

ORIGINAL 3-27

detailed analysis of the principles of operation of theoverall equipment and its functions. The functionaldevelopment of the equipment outputs in every modeof operation is described. The descriptions are pre-sented in successive levels of increasing detail: overalllevel, major functional level and circuit level. Circuitlevel descriptions are limited to those not describedin the EIMB, NAVSEA SEOOO.00.EIM.120. The textis directed to and supported by functional block dia-grams and simplified schematic diagrams in this chapter,and to the functional troubleshooting diagrams anddetailed schematic diagrams in C h a p t e r 5 ,Troubleshooting. Digital circuits are described usingconventional logic symbols and notations, with ade-quate flowcharts and functional descriptions forcomplete understanding. The organizational structureof this chapter parallels, as much as possible, thefunctional arrangement of data in Chapter 5.

CHAPTER 4 – SCHtiDULED MAINTENANCE

This chapter contains preventive mainte-nance procedures and performance tests requiredwhich will establish confidence that the equipmentand the functions being tested will perform withinallowed tolerances until the next scheduled test orpreventive maintenance action. It is intended thatthe procedures provided in this chapter shall reflectthe specific scheduled maintenance procedures devel-oped for the Preventive Maintenance System (PMS)Maintenance Requirement Cards (MRC). However,the scheduled performance test provided by thetechnical manual shall include references to trouble-shooting or corrective maintenance actions if the testvalues are not within tolerances. In case of conflictsbetween the PMS documentation and the technicalmanual, the PMS documentation shall take prece-dence.

CHAPTER 5 – TROUBLESHOOTING

The troubleshooting chapter providessufficient information to localize mrdfunctions to arepairable assembly. Troubleshooting aids suppliedinclude a troubleshooting index; relay, lamp andprotective device index; maintenance turn-on proce-dure, system troubleshooting information, and indi-vidual equipment function troubleshooting proce-dures. The troubleshooting index provides a listingof the major and supporting functions of the equip-ment with references to the appropriate trouble-shooting diagrams, procedures, and supportingfunctional descriptions. The maintenance turn-on



d

procedure provides a method of turning on the equip-ment when the normal procedures fail due to internalmalfunctions. The procedure normally is used whenproblems occur during the normal turn-on proceduresor the equipment is shut down due to overloading. Theprocedures are helpful in localizing primary powermalfunctions to an area on a troubleshooting diagramfrom which circuit tracing can be started. The relay,lamp, and protective device indexes provide a listingof these items by reference designation. For each itemthe functioned name, energizing parameters, and directreference to an appropriate troubleshooting diagramare included. Troubleshooting procedures support thetroubleshooting diagrams. These procedures guide thetechnician in the logical order of isolating a fault todefective items within each equipment function. Thisinformation directs the technician to observe meters,fuses, circuit breakers, valves, built-in test equipmentand other available indications showing the presenceof trouble. Troubleshooting diagrams consist of signalflow diagrams, power distribution diagrams, pipingdiagrams, control diagrams, logic diagrams, mainte-nance schematic diagrams, and dependency diagrams,as required. Signal flow diagrams, the most significanttroubleshooting aid, consist of detailed block diagramsillustrating the functional development of each majorfunction from its ongin to its output. The flow pathbegins with one or more initial inputs and proceedsthrough each unit, assembly, and subassembly influenc-ing the signal flow. All check or test points necessaryto isolate the trouble to lowest level hardware blockare highlighted. Test equipment setup and testparameters are provided to define satisfactory opera-tion. Either fault logic diagrams or maintenancedependency matrix charts are included in this chapter.These troubleshooting aids enable the lesser trained orless experienced technician to isolate malfunctions ofthe equipment.

CHAPTER 6 – CORRECTIVE MAINTENANCE

This chapter contains instructions,within the ability of the electronics technician, toadjust and align the equipment, remove, repair andreinstall and align all repairable parts and modules,subassemblies and assemblies. These instructionsidentify the action to be accomplished, safety precau-tions to be observed, tools, parts, and test equipmentand materials required. It lists preliminary controisettings, test equipment set up instruction, and step-by-step instructions with supporting illustrations to

accomplish the maintenance task. This chapter isusually broken down into two sections, alignmentand repair.

CHAPTER 7 – PARTS LIST

This chapter lists and identifies allshipboard, tender and shore-based repair parts andattaching hardware. Included are a list of units, partslist, list of common items, list of attaching hardware,list of manufacturers and parts location illustrations.The parts listing is in order of item reference desig-nation and provides a description, part number, manu-facturer’s code, attaching hardware and figure refer-ence for each item. The list of common items, list ofattaching hardware and list of manufacturers provideexpanded data as referenced in the parts list. Partslocation illustrations appear in reference designationsequence at the end of the chapter.

CHAPTER 8 – INSTALLATION

This chapter contains drawings andinformation pertaining to site selection, special toolsand materkd requirements, unpacking and handling,preparation of foundations, assembly procedures,mounting instmctions, bolting diagrams, safety pre-cautions, clearance requirements, cooling requirements,and recommendations for reducing electric andmagnetic interference. Installation checkout pro-cedures provide for equipment checkout in threephases: installation inspection and pre+mergizingprocedures, turn-on and preliminary tests, and install-ation verification tests. An installation standardssummary sheet provides a checklist with spaces forrecording the results of all installation verificationtests.

3-3.3.2.1 DistributionTwo copies of the TM for a particular

equipment are provided for each equipment. Inaddition, the Command supplies file copies toactivities concerned with the installation and main-tenance of the equipments or with the training ofelectronics personnel. Supplies of manuals remainingafter initiaf distribution are stored at the Navy Publi-cations & Forms Center, PhiIadelphia, for issue toindividual activities. When the supply of manuals is

extremely limited, special justification may be re-quired to obtain copies. Manuals for instruction andstudy can be issued only to Navy and Marine Corpsschools, and then only i~

OR1.GINA.L


quantities consistent with the available stock. Advance,preliminary, or temporary technical manuals maybe furnished where a delay in completing the finalmanual is anticipated. As a general rule, returnpostcards are included under the front covers ofthe manuals. These cards provide a ready meansfor informing Contractors of where the completedfinal manuals are to be sent. To ensure receipt ofthe final manuals, the postcards should be filledin and returned promptly. Advance, temporary,and preliminruy publications are to be destroyedupon receipt of final technical manuals, as indicatedin the promulgating letter in the final books. If themanuals to be destroyed are classified, disposal mustbe in accordance with existing regulations coveringthe destruction of classified material. The instructionswhich accompany changes to technical manualsindicate the desired disposition of materhd removedfrom the basic publications.3-3.3.3 Functionally Oriented

Maintenance ManualThe differences between a Functionally

Oriented Maintenance Manual (FOMM) and a conven-tional manual aw: the use of color, unique diagram-ing techniques, and the maintenance dependencycharts. Color is used to define hardwae boundaries,show functional entities, and show control locations.A functional entity may be a piece part, piece partsformed into a circuit, a group of circuits, or a majorfunction. Hardware boundaries are shown as shades ofgrey. When a unit, assembly, and subassembly areshown on the same diagram, the lightest shade of greyrepresents the unit, the next darkest shade of greyrepresents the assembly, and the next darkest shade ofgrey represents the subassembly. A diagram showingan assembly uses the lightest shade of grey to repre-sent the assembly and darker shades for subassemblies.Functional entities are shown within shades of blue.The lightest shade of blue may represent a single func-tional entity, or a functional entity with two or moresubfunctional entities within the next darkest shade ofblue. Front panel controls are shown in white boxeswithin black borders. Internal controls are shown ingrey boxes that represent the proper hardware level.The white and grey boxes are shown within blue shades,whenever possible. Diagraming is the heart of tbeFOMM, not because of the pretty shades of blue andgrey, but because of the functional diagramingtechnique. Each diagram, whether it be overall func-tion, major function, or blocked schematic, is function-ally reduced until it fits on one right-hand page.Functions removed from the main diagram are placed

.ORIGINAL 3-29

on the following right-hand pages. Each diagram on aright-hand page becomes the focal point for trouble-shooting and repair information. Diagrams and theircorresponding maintenance dependency charts(MDCS), or fault logic diagrams (FLDs) are used fortroubleshooting. MDCS are preferred. FLDs are usedwith major functional diagrams containing complexdigital circuitry. The maintenance dependency chartdisplays the sequence of power or signal flow in theequipment. Each horizontal line displays an event suchas a lamp lighting, a relay energizing, or an availabilityof a signal or voltage. Symbols on the event linesindicate the functional entities, circuit elements, orprevious events that the event is dependent on. Thesymbols are located within the vertical columns, whichidentify the functional entities and circuit elements.When an event or signal availability is not pwsent,the previous events, signal availabilities, functionalentities, and circuit elements on which the event isdependent can be readily ascertained. An event boxindicates input or output signal or indication. Nomen-clature in the event box specifies the type of actionand availability of the event. A black event box withwhite lettering indicates front panel observable. Awhite event box with black lettering indicates a circuitpoint at which an event or availability may bemeasured. The circuit identifier codes and all symbolsused on the diagrams and maintenance dependencycharts are shown in tabular form with an explanationof their meanings in each manual. In order to usediagrams and maintenance dependency charts effective-ly, the technician must familiarize himself with sym-bols used and their meanings. The FOMM providessupport, and troubleshooting and repair informationfor a particular equipment or system. For convenience,support information is separated from troubleshootingand repair information by volumes. Depending on thesize of the FOMM, volumes may be further subdividedinto parts.

VOLUME 1 – SUPPORT INFORMATION

The support volume includes frontmatter and sections entitled: general information,operation, theory of operation, scheduled mainte-nance, installation, and parts list. This volume uses8% x n-inch pages.

FRONT MATTER

Front matter consists of conventionalinformation and a functional index.



SECTION 1– GENERAL INFORMATION

This section provides information foreasy and rapid determination of the purpose, physicaland functional characteristics, and operational capa-bility of the equipment or system.

SECTION 2 – OPERATION

This section contains manual and auto-matic procedures for routine and emergency operation,safety precautions, operating and equipment limita-tions. Controls, relationship of controls to each other,and their effects on displays are described.

SECTION 3 – THEORY OF OPERATION

This section contains a description ofthe generaI principles of operation beyond the actualfunctioning of the equipment or system contained inVolume 2. Examples of this generaJ information wouldbe gun-fire control problems, sonar or radar principles,concepts of a communication system, etc. Also, thereis an amplification of the keyed text used in Volume 2to explain the operation of a function or circuit.

SECTION 4 – SCHEDULED MAINTENANCE

This section contains preventive main-tenance procedures and performance test instructions.

SECTION 5 – INSTALLATION

This section contains drawings andinformation required for installation.

SECTION 6 – PARTS LIST

This section contains a top-down break-down of all the parts. This separate parts list is pro-vided when requested in a contract. Volume 1 of aFOMM System Manual contains rdl six of the precedingsections numbered differently, and two additionalsections: safety precautions, and alignment.

SECTION 2 – SAFETY PRECAUTIONS

This section describes the hazardsassociated with the system operation andmaintenance.

3-30

SECTION 6 – ALIGNMENT

This section contains corrective adjust-ment procedures and support information necessaryto restore electrical and mechanical alignment betweenvarious system equipment.

VOLUME 2 – TROUBLESHOOTING AND REPAIR

The troubleshooting and repair volumeprovides information for troubleshooting from theoverall function, through the major functions, down tothe faulty circuit or piece part in progressive stages.This volume includes front matter, overall function,major function, and hardware information. Thisvolume uses 11 x 17-inch pages.

FRONT MATTER

Front matter consists of conventionalinformation and a functional index, a description ofspecial terms and symbols, integrated circuit data, andan explanation of MDC usage.

OVERALL FUNCTION INFORMATION

Overall function information consistsof a functional family tree, a hardware familytree, an interconnecting cabling/piping diagram,a turn-on/check-out chart, and functionaldiagram, keyed text, MDC, and alignmentinstructions. A funct ional fami ly t ree showsthe major functions and subordinate functions. Ahardware family tree shows the units, assembliesand subassemblies. An interconnecting cabling/ pipingdiagram shows and identifies cabling and piping used toconnect units and interfaces with the ship services. Aturn-on/check-out uses the sensory indications to bringthe equipment from a cold state to a hot state, andcheck it out. The overall functional diagram showseach major function as a first level blue shaded blockwith front panel controls. The signal flow between themajor functions and interfacing equipment is shown.This diagram with the overall MDC is used to isolatea faulty function. A keyed text is used to describethe overrdl functional diagram. The overall MDCmatches the signal flow through the overall func-tional diagram. Overall alignment procedures adjustand align all adjustable parts including interactingadjustments.

ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-00-E IM-160 ROUTINE MAINTENANCEAND MAINTENANCE AIDS

MAJOR FUNCTION INFORMATION

The major function information consistsof a diagram, keyed text, and maintenance dependencychart or fault logic diagram. Major function diagramsfall into four general categories: analog, logic, powerdistribution, and ground/return. The diagrams are con-structed to show the functional flow of signals throughunits with their piece parts, assemblies, and subassem-blies as they are connected in the major function. Thediagrams, with their MDCS, are used to isolate a faultyassembly or piece part within the major function. Akeyed text is used to describe the major functiondiagram. The major function MDC matches the signalflow through the major function diagram.

HARDWARE INFORMATION

A separate hardware information pack-age is made for each unit. When the unit blockedschematic diagram is too large for a 11 x 17-inch page,a separate hardware information package is made forone or more of the unit’s assemblies. The same tech-nique is used for assemblies and subassemblies. Ahardware information package consists of a blockedschematic diagram, a keyed text, an MDC, alignmentand repair data, parts data, and a wiring diagram orwire list. Blocked schematic diagrams are constructedto show the functional flow of signals through func-tional entities of a unit, assembly, or subassembly.A functional entity is two or more parts grouped intoa circuit, or a separate piece part. The diagrams, withtheir MDCS, are used to isolate a faulty functionalentity. Voltage information on the diagram is usedfor fault isolation within functional entities containingvacuum tubes or transistors. A keyed text is used todescribe the blocked schematic diagram. The hardwareMDC matches the signal flow through the blockedschematic diagram. Alignment and repair containsprocedures used for access, and to return the equip-ment or system to normal operation after correctivemaintenance. Parts data contains part location diagramand a parts list. A wiring diagram is a pictorial presen-tation of point-to-point wiring. A double-entry wirelist may be substituted for a backplane wiring diagram.3-3.3.4 Electronics installation

and Maintenance BooksThe Electronics Installation and

Maintenance Books (EIMB) is a series of authoritativepublications which provide field activities with informat-ion on the installation and maintenance of electronicequipment under the technical control of the Naval Sea

OR IG 1 rJAL 3-31

Systems Command. The EIMB consists of thirteenseparate volumes or handbooks in order to ensure cov-erage of all Naval electronic equipment. The followingis a list of each handbook by title and NAVSEAnumber.

Title NAVSEA No.

The Complete ELMB Series SEOOO-OO-EIM-OOOGeneral Handbook SEOOO-OO-EIM-1OOInstallation Standards Handbook SEOOO-OO-EIM-11OElectronic Circuits Handbook SEOOO-OO-EIM-120Test Methods and Practices

Handbook SEOOO-OO-EIM-130Reference Data Handbook SEOOO-00-EIM-140RFI Reduction Handbook SEOOO-OO-EIM-150General Maintenance Handbook SEOOO-OO-EIM-160Communications Handbook SEOOO-OO-EIM-O1ORadar Handbook SEOOO-OO-EIM-020

Sonar Handbook SEOOO-OO-EIM-030Test Equipment Handbook SEOOO-OO-EIM-040

Radiac Handbook SEOOO-OO-EIM-050

Countermeasures SEOOO-OO-EIM-070

Tabular Separators (Stock#)0967-LP-000-0009(Equipment Books Only)

The information contained in the ELMB series issupplemental to equipment technical manuals andrelated publications.3-3,3.4.1 Scope

The handbooks of the EIMB series aredivided into two categories: general informationhandbooks, and equipment-oriented handbooks. Thegeneral information handbooks contain data of interestto all personnel involved in installation and mainte-nance, regardless of their equipment specirdty. Theequipment handbooks are devoted to information ona particular equipment class; they provide specificequipment test procedures, important adjustments,circuit applications, general servicing information,and field change identification data. The technician,by using the EI.MB, will tend to reduce time-consuming research, and obtain supplementaryinformation helpful in servicing and maintaining hisequipment.3-3.3.4.2 Distribution

The distribution of the EIMB hand-books and handbook changes is a joint effort by theNaval Sea Systems Command, SEA 05 L341, NationalCenter #2, Room 7E48, Washington, D.C. 20362, andthe Navy Publications & Forms Center, Philadelphia.Distribution policy is established by NAVSEA 05L341Activities


not already on the EIMB distribution list and thoserequiring changes to the list should submit corres-pondence to:

Naval Sea Systems Command, SEA 05L341National Center #2, Room 7E48Washington, D.C. 20362

3-3.3.5 Electronics Information BulletinThe Electronics Information Bulletin

(EIB), Stock Number 0967-LP-O01-3XXX, is anauthoritative publication, published bi-weekly, andforwarded to all Naval ships and Naval electronicsinstallation and maintenance activities. The EIBcontains advance information of field changes, instal-lation techniques, maintenance notes, beneficial sug-gestions adopted by various yards and bases, and noti-fication of technical manual and EIMB revisions andchan~s with the latest applicable data and stocknumbers. Unless otherwise indicated, the maintenancerequirements prescribed in the various issues of theEIBs are consistent with those contained in thePlanned Maintenance System. All articles, includingthose under the cognizance of Naval ElectronicSystems Command (NAVELEX), have been authenti-cated and are authoritative in nature. Accordingly,reference may be made to a particular issue of theautbority for adoption of ideas contained therein.Nothing in the EIB publication authorizes interfacechanges between equipment and systems, or betweenequipment and ship. Articles of lasting interest arelater transcribed into the EIMB except for fieldchanges and corrections to publications. EIBindexes (A and B) are distributed automaticrdly asa change to the Genera l EIMB handbook,NAVSEA SEOOO-OO-EIM-1OO. EIB indexes (A and B)provide a comprehensive listing of articles published in

3-32

the EIB and identify the EIB in which each articleappears. Index A lists, by equipment type numberand/or name, articles pertaining to specificequipments (i.e., AN/SPS-10, LS-458/SIC, MK 23MOD 3 GYRO COMPASS, TACAN, TED-1 ,TEKTRONIX TYPE 316 OSCILLOSCOPE, etc.). Thisindex is prepared using an automatic data processingsystem with a basic columnar sort sequence, and,therefore, many entries are not in their true numericsequence. For example: R-1051/URR precedesR-390/URR and AN/SPA-33 precedes AN/SPA-4.Field changes are identified by “FC>’ following theequipment type numbers, i.e., R-390 A/URR-FC-5.Index B lists, by subject, all articles of generalinformation not pertaining to specific equipment (i.e.,Coxial Lines-Prevention of Corrosion Due to SaltSpray on).

3 4 SOLDERING ANDREPAIR SKILLS

The majority of modem electronicequipment incorporate small (miniature) or verysmall (microminiature) components. Such compo-nents range in size from large-scale integrated circuits(LSI) to the now familiar transistor. Because of their sizeand composition, mostminiature and micro-componentsare heat sensitive, and many are static sensitive. The tech-nician must develop the proper soldering skilk to servicethese componentswithoutdamaging them. The followingsections will aid the technician in developing suchskills. Prior to performing any microminiature repair,the technician must have acquired general high-reliability soldering skills. Section 4 will therefore bedevoted to discussing these essential skills. Repairs ofminiature, microminiature components and circuitswill then be discussed in Sections 5, 6 and 7.

d

ORIGINAL

L

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 SOLDERING TECHNIQUES

SECTION 4

SOLDERING TECHNIQUES

4-1 INTRODUCTION

The efficiency of electronics equipmentis dependent, to a very large degree, upon the qualityof workmanship employed and the type of materialsused in the soldering of its electrical connections.An appreciable portion of equipment failure can betraced directly to poorly soldered connections orjoints. Electronics equipments aboard ship are sub-jected to continual vibration and frequent shock.Therefore, it is imperative that all soldering be donewith the utmost care.

4-2 SOLDER TYPES

Solder is a metal alloy consisting of twoor more metals used in various percentages to form

I /

60140

Figure 4-1. TIN/LEAD

ORIGINAL 4-1

the solder alloy. The alloy most widely used in elec-tronics soldering consists of TIN and LEAD withoutspecial additives. The most common TIN/LEADsolder alloys are 60/40 and 63/37. TIN/LEAD solderalloys are always given as a percentage with the TINcontent listed first; that is, 60/40 solder consists of60% TIN and 40% LEAD. The TIN/LEAD fusiondiagram (Figure 4-1) shows a plot of various TIN/LEAD solder alloys versus temperature. Note thatat 361“F all TIN/LEAD solders (from 15/85 to 95/5)change from a solid to a plastic (partird liquid) stateexcept one. An alloy which has a single sharp meltingpoint and changes directly from a solid to a liquidwith no plastic state is called a EUTECTIC alloy.The only TIN/LEAD solder alloy with eutecticcharacteristics is 63/37, as the diagram indicates. The63/37 solder is known as Eutectic Solder. An overall

\ I

EUTECTIC POINT

Fusion Diagram

SOLDERING TECHNIQUES NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

4

evaluation of Figure 4-1 diagram reveals that differentalloys reach full liquid state at different temperatures.It also reveals that as solder is heated, it passes from asolid state through a plastic state and then into a liquidstate, with the exception of the eutectic point at whichno plastic state exists. The most critical area of concernduring a soldering operation is the time-temperaturerange during which the solder is in a plastic state. Whilein this plastic state the solder is a combination of liquidTIN/LEAD alloy with solid pure metal crystals ofeither TIN or LEAD. Any physical movement of thesolder itaelf, while cooling through the plastic state,will permanently damage the structure of the solderalloy, resulting in a fractured solder connection. Forthis reason, eutectic solder (63/37) is the best generalpurpose, high-reliability, electronics solder. Although60/40 solder is less acceptable for electronics soldering,it has the advantage of forming a slightly stronger jointthan does the 63/37 solder. It has, however, the dis-advantage of lying in the plastic range from 361 “F to370 “F, with the attendant chance of fractured solderconnections.

4-3 SO LDERIPJG FLUX

The purpose of soldering flux is toremove surface oxides from metals to be soldered. Allmetals oxidize when exposed to air. The process ofoxidation causes a thin film of oxide, which is non-metallic, to form on the surface of the metal. Goodmetal-to-metal contact must be obtained beforesoldering action may take place, but the oxide filmprevents this contact and must be neutralized orremoved. Soldering flux chemically breaks down sur-face oxides, causing the oxide film to loosen andcome free from the metals being soldered. Thesefluxes may be divided into three general types orclassifications:

1. Chloride (commonly called“acid”) type flux.

2. Organic type flux.3. Rosin or resin type fluxes.Each group of fluxes has characteristics

specific to that group. The chloride fluxes are inor-ganic salts and are the most active of the three fluxgroups. They are not suitable for electronics solderingsince they are highly corrosive, usually electricallyconductive, and are difficult to remove from tbeworkpiece. The organic fluxes are nearly as active asinorganic fluxes, somewhat less corrosive, but areunsatisfactory for shipboard electronics solderingbecause they must be removed completely to inhibitcorrosion. Rosin-type flux is ideally suited to

4-2

electronics soldering due to its unique characteristics.Inert at normal temperatures, flux becomes highlyactive at soldering temperatures. This characteristicmakes rosin totally noncorrosive, except at solderingtemperatures. Resin fluxes are rosin-based, with addi-tives that change some of the characteristics of thepure rosin flux. To attain highest reliability in makingelectronics solder joints, the use of flux is a necessity.Flux is available as both an external agent and as anintegral part of the solder. As an external agent, theflux is applied to the connection by hand prior tosoldering. Externsd fluxes range from a very thinliquid to a thick, heavy paste. Most paste fluxes con-tain zinc chloride as an activating additive. If zincchloride has been added, it will be so stated on thecontainer. (NOTE: Fluxes containing zinc chloride mustnever be used as they are corrosive.) Nearly all elec-tronics soIder in use today contains flux as an inte-gral part of the solder by making the solder with anintegral flux core. However, it is often highly desirableto use an external flux, even when also using a fluxcured solder. Two types are recommended:

1. Kester Solder Co., No. 1544with No. 104 thinner.

2. Alpha Metals Co., No. 711 withNo. 412 thinner.

Although solder forms an actual inter-metallic bond with solderable metals, it does not doso by fusion, as in brazing or welding, where all metalsto be bonded are molten and fused together. Thewetting action of solder lies in the degree of ease andcompleteness with which the solder spreads over thesurface of the metal being soldered. The complete-ness of the wetting action is measured by the tangentangle where the solder meets the surface of the metalbeing soldered. A very small angle is an indication ofthorough and complete wetting. A large angle formedby a sphere or bubble of solder (similar to a drop ofwater on a waxed surface) is an indication of poorwetting action and may involve an unsatisfactory“cold solder” joint. The completeness of the wettingaction is one of the prime indicators of quality andreliability when inspecting a solder joint.

4-4 METALLIC PLATINGS

It is the function of metallic platingsto protect the associated metal from oxidation, and toassure the solderability of normally non-solderablemetals. Non-solderable metals are used to closelymatch the thermal expansion of glass seals on capaci-tors, transistors, diodes and other electronic compo-nents. Plating on this type of lead is normally gold,

ORIGINAL


which is very porous, and is applied relatively thickly.Care must be taken not to remove the plating from thistype of lead.

4-4.1 CHARACTERISTICS A N DFABRICATION OF AQUALITY SOLDER JOINTThe physical appearance of a quality

solder joint shall be as follows:1. Smooth, shiny, mirror-like surface.2. Free of pits, protrusions, or other

blemishes.3. No base metal showing at any

point.4. Smooth, concave fillet at all points

of contact.5. Complete wetting action which

shall show no distinct inlets at the edge of the solderedarea.

Also the solder must wet and flowsmoothly over afl surfaces, with no sharp edge orridge at any point. The preferred quantity of solderforms a smooth, concave fillet from a point haff-wayup the side of the lead. The contour of the wire shouldbe clearly visible through the solder. (If stranded, theindividual strands must he visible. )

4-4.2 RECOGNITION AND CAUSESOF SOLDER JOINT DEFECTSCommon defects include: dirty solder

joint due to lack of good wetting; cold solder jointsdue to dewetting around all or most of the connec-tions; and small protrusion or tip of solder where thesoldering iron was removed. Fractured or disturbedsolder joints are usually semi-shiny with good wetting.A prime indication is a spiderweb or cracked, fissuredappearance. In an overheated solder joint, the surfaceis quite dull, with a rough, grainy appearance. A“dead” solder joint is crusty, wrinlded, and a very darkdull color.4-4.2.1 Causes of Common Defects

Dirty solder joints are caused by oxida-tion or other foreign matter interfering with the wet-ting action. Cold solder joints are caused by insuffi-cient heat or poor heat transfer to the joint. Fracturedjoints result from physical movement of the joinwhile the solder is in the plastic state. An overheatedsolder joint is caused by excessive heat for too long atime. Dead solder is due to extreme overheat and isgenerally only found on the tip of a soldering ironwhen the iron is not in use.

ORIGINAL 4-3

4-5 INSTALLATION ANDSOLDERING OF COMPONENTS

4-5.1 COMPONENT POSITIONINGProper positioning of a component on

the board is as follows:1. In repair, replacement components

should always be installed in conformance with theoriginal configuration.

2. Component bodies shall be cen-tered between the lead mounting points wheneverdesign permits.

3. Replacement components shall bemounted so as to make afl possible identificationmarkings readable without disturbing the component.

4. When a series of components aremounted in the same style and direction, they shouldbe placed so that all markings are all readable from asingle point, giving due regard to polarity requirements.

5. Any mounting hardware removedduring disassembly shall be replaced when installingnew components.

4-5.2 COMPONENT LEAD SHAPINGProper methods of shaping component

leads for mounting on a printed circuit board are asfollows:

1. Component leads shall always hestraightened and cleaned prior to bending.

2. Leads may be straightened by hand,using anything that will not cut or scrape the lead.

3. Erasure cleaning of leads is pre-ferred. Use an ink-type eraser (white), as other typeswill leave an oily film on the lead. After cleaningthe lead, the final cleaning step shouldbe to wipe thelead thoroughly with solvent to remove all residueleft during cleaning.

4. The minimum distance between theseal, where the lead enters the body of the component,and the start of the lead bend shall be not less than adistance equal to twice the diameter of the lead itself.

5. The minimum distance betweenany weld bead on the lead and the start of the bendshall be not less than a distance equal to twice thediameter of the lead itself and the bend shall notbe between the weld bead and the component body.

6. The minimum radius of the benditself (sharpness of the bend) shall be not less thana distance equal to the diameter of the lead, and thebend shall be 900 at all times, except when forminga stress relief bend.


4

—

7. After bending leads, and beforeinserting component on the board, always reclean theleads with solvent to remove skin oils and salts presentdue to finger contact.

4-5.3 CIRCUIT BOARDPREPARATIONThe first step in preparing for compo-

nent installation is to thoroughly clean the circuitboard. A white ink-type eraser will remove lightoxides. Always clean circuit board with solvent and aKimwipe after abrading. Never allow the solventto evaporate, but wipe up promptly with a clean dryKimwipe. Solvent type cleaning may also be done withan acid brush which has soft bristles and will notscratch the conductor surfaces. Wipe dry with aKimWipe.

4-5.4 PROPER SHAPINGTECHNIQUESThe next step in component installa-

tion involves bending and cleaning the componentlead, prior to insertion in the board, as follows:

1. A nylon rod or orangewood stickmay be used to bend component leads. Always holdthe component body immobile and bend only the pig-tail end of the lead with a smooth wiping motion ofthe finger.

2. When using round-nose pliers toform bends and stress relief loops, always cover suchjaws with masking tape to cushion them. Use extremecare not to dent the component lead.

3. The initial step in forming stress-relief loops is to make a standard 90” bend in the lead.

4. To finish the stress relief bend, gripthe lead just beyond the 90” bend and wipe the pig-tail end smoothly around the plier jaw, forming a180 “ 100P.

5. After bending and inserting thecomponent into the board, the next step is to properlyform the lead termination.

6. In forming a straight-through ter-mination, the lead is simply cut to proper length, usingflush-cutting pliers.

7. To form a semi-clinched termina-tion, grip the lead with pliers and bend in the direc-tion of a run to a 45” angle. Avoid pulling on the lead,as this will place unwanted stress on the componentbody.

8. After bending, cut the lead withflush-cutting pliers. The flush side of the cutter must al-ways be kept toward the board, butat900 with the lead.

4-4

9. For full clinched terminations, thebending and cutting procedure is the same as for semi-clinched leads.

10. An orangewood stick, which willnot damage the run or pad area in any way, may beused to fully clinch the pigtail down to the run sur-face.

4-5.5 COMPONENT LEADTERMINATIONComponent Lead Terminations are to

be made as follows: (refer to Figure 4-2)1. After installing the component on

the board, the proper lead termination must be madeprior to soldering.

2. Prior to shaping lead termination,excess lead may be cut off with a flush cuttingtool.

3. On clinched terminations the leadlength shall be not less than the radius of the pad andnot greater than the diameter of the pad.

4. Semi-clinched termination shallhave the same Ieadlength specifications as full clinched.

5. All clinched terminations must bebent in the direction of the run.

6. Clinched terminations must contactthe run surface and not overhang any part of the runedge.

7. The lead length on straight-throughterminations shall be not less than one lead diameterand not more than two lead diameters above the boardsurface.

4-5.6 SOLDER CONNECTIONCHARACTERISTICSThe characteristics of high-quality

printed-circuit solder connections are as follows:1. The solder area extends beyond

the cut end of full-clinch leads sufficiently to forma fillet.

2. Solder flows to the edges of the padin all cases.

3. If the run or pad is plated andplating has been removed, solder must have flowedover all exposed base metal.

4. On a single-sided board, the solderforms concave fillets between the lead with no internalvoids.

5. On a double-sided board withplated through-holes or flat-set eyelets, the soldershould completely fill the hole and cover the padson both sides of the board.

OR IGINA1.

GENERAL MAINTENANCE NAVSEA SEOOO

6. The soldered area of a funnel-seteyelet forms three separate solder joints: one on eachside between the outer flanges and the board, and onethrough the hole between the inside of the eyelet andthe lead.

7. The solder finish must exhibit asmooth, gleaming, mirror-like appearance, no pits orholes shall be in evidence, and all fillets must he concave.

4-5.7 HIGH-QUALITYSOLDERING TechniquesThe techniques for making high-quality

printed-circuit solder connections include the following:1. Correct application of proper flux.2. Only flux-cored solder should be

used, as it provides automatic application of flux tothe connection while soldering.

3. For large areas or rapidly oxidizingsurfaces, a quantity of external flux may also beapplied to the joint prior to soldering.

4. Proper heating can only be accom-plished with the correct soldering tool.

5. A typical soldering iron employedin high-reliability soldering has several tip styles whichare used for different masses to be soldered.

6. The tip is inserted into the bottomof the iron’s hole and the set screw tightened gentJybut firmly. Excessive force will cause the screw toheat-seize.

7. The soldering iron is voltage-controlled to more closely match tip temperature tothe mass to be soldered.

8. Upon completion of cooling,loosen and remove tip to prevent heat-seize caused byoxidation.

9. Normally, tips used in high-reli-ability soldering are clad, and should therefore becleaned only with a platers brush or crocus cloth ifheavily oxidized.

10. When the tip reaches solderingtemperatures, a quantity of solder is to be melted ontothe tip and then left there to prevent oxidation untilready to use.

11. Before using the soldering iron tomake a joint, all solder must be removed from thetip, using a brush and a Kimwipe.

12. After the excess solder has beenwiped off, thermal-shock the tip on a wet sponge toprovide a clean, dry tip for soldering.

13. To achieve proper heating of theconnection, the tip mass and tip temperature must becapable of rapidly heating the mass of the joint to besoldered to the melting temperature of solder.

ORIGINAL 4-5

-OO-EIM-160 SOLDERING TECHNIQUES

4-5.8 APPLICATION OF SOLDERBefore applying heat to a joint, a

thermrd shunt should be attached to component leadswhen dealing with heat sensitive components such asdiodes and transistors. When component leads do notprovide access for the thermal shunt attachment dueto the use of mounting hardware, EXTREME caremust be used to prevent heat damage. A solder bridgeis formed by melting a small amount of solder at thejunction of the tip and the joint. This allows maximumpossible heat transfer rate from the tip to the joint.After the prepared tip is placed in physical contactwith both the lead and the pad and the heat bridgehas been established, the solder is applied to formthe solder bond.

NOTE

Use only clean solder.

The iron or joint should not be movedduring the soldering operation, even on double-sidedboards, since cleaning and heating of the joint areawill allow the solder to flow through the hole andfrom the entire joint with a single application (exceptfor holes without metallic reinforcement). Solder isapplied to the connection by “painting” the solderinto the area to be soldered, using a circular motion.Start by forming fillets along the sides of the lead;finish by filling in the large flat area of the pad.

4-5.9 CLEANING AFTERSOLDERINGAfter soldering, all flux residues must be

removed by solvent cleaning. Two solvents areapproved for circuit board cleaning. The recom-mended, in order of their cleaning ability, are:

1. 99.5% puw ethyl alcohol (normallynot available); and

2. 99.5% pure isopropyl alcohol.

4-5.10 QUALITY INSPECTIONSTANDARDSAll printed circuit board soldered

connections should be inspected for quality of work-manship. The standards of acceptance and indica-tions to look for include the following:

1. Solder quantity:a. Concave filletsb. Lead contour visible

2. Solder finish:a. Bright, gleaming finishb. No pitx or holes


3. Wetting action:a. Smooth feather ing of a l l

solder edges.b. No bays or crevices in the

edge of the solder flow.4. Lead termination:

a. Proper lengthb. Proper positioningc. Pigtail properly flush-cut

5. Board, conductor and componentdamage:

a. Overheated boardb. Conductor delaminationc. Conductor nicks and scratchesd. Proper component installations

4-5.11 FINAL INSPECTIONA final inspection of the repaired

printed circuit board should include the followingstandards of acceptance and indications of reliability:

1 . Board res tored to i t s or ig ina lconfiguration.

2. No visible degradation to any partof the assembly.

3. Repair made with the same typecomponents and materials as used initially by themrmufacturer.

4. Repairs made should be nearlyindistinguishable by visual inspection, unless they areof a higher quality than the original work of themanufacturer.

4-5.12 CON FORMAL COATINGIDENTIFICATIONThe six basic types of conformrd coat-

ings and their specific characteristics are as follows:1. Epoxies:

a. Normally hardest of the sixtypes.

b. Application of heat at or nearthe solder melting temperatures causes the epoxy toovercure, resulting in its breakdown into a powderysubstance.

c. Epoxy forms the strongest sur-face adhesion bond of all the conformal coatings. Itwill not chip or peel, and may be considered nearlyunbreakable under physical stresses.

d. VeW few solvents will attackepoxy, and the destructive ones will also attac”k the oboard and ita components.

e. The texture of epoxy is nor-mai[y hard, smooth and non-porous.

4-6

2. Acrylic Lacquer:a. Acrylics are relatively hard and

similar in appemance to epoxies, but yield morereadily to scraping and cutting.

b. Heat readily softens most acry-lics; however, a gummy residue often results.

c. The adhesion of acrylics isusually a surface bond and will often chip and flake,although it is relatively strong.

d. Solvents such as 1.1.1, trichlor-ethane and xylene, readily attack and soften mostacrylics.

e. The texture of acrylics is nor-mally smooth, non-porous, medium hard with a glossyfinish.

3. Polyurethane:a. Some polyurethane coatings

have widely varying degrees of hardness which rangefrom an extremely hard type, similar to epoxy, to arelatively soft consistency which is similar to an RTVcompound.

b. Most polyurethane tend tosoften rapidly and exhibit a putty-like consistency ator near soldering temperatums.

c. Plastic solvents are generally theonly type that will attack polyurethane; they willalso attack the components and circuit board.

d. Texture is normally smooth,glossy and non-porous but may be dented or scratchedunder light pressure.

4. Varnish:a. The hardness of varnish will vary

with age: new varnish is relatively hard and tough, whileold varnish tends to be brittle and flakes very easily.

b. Heat, at or near soldering temp-erature, causes varnish to liquify and give off a verystrong odor of linseed oil.

c. Organic solvents such as alcoholand mineral spirits readily attack varnish, but tend toleave a gummy residue upon evaporation.

d. Varnish is often lumpy inappearance and has a semi-glossy look.

5 . RTV:a. RTVS have a rubbery, pliable

consistency.b. Heat, chemicals and solvents

have little or no effect on RTVS.6. Parylene:

a. Parylene is considered to be ahard coating, normally as hard as epoxy.

b . Nomldly, solvents have noeffect upon parylene.

ORIGINAL


c. High heat (approximately 480-500 “F) will remove parylene but will also probablydamage the workpiece.

d. Texture is smooth, dull andnormally clear.

4-6 RESOLDERING ANDREMOVING COMPONENTS

The resoldering and removal of compo-nents from printed circuit boards is just as critical as theinstallation and soldering of circuit board components.The following subparagraphs discuss the recognition,identification, resoldering methods, and procedures ofsolder joints as well as proper tool usage, cleaning, andinspection.

4-6.1 RECOGNITION OFSOLDER JOINT TYPESTo recognize the various solder joint

types, the board circuitry style, the lead terminationstyle, and the style of reinforcement must be consid-ered. Of the three considerations, the board circuitrystyle (Figure 4-2) is the easiest to recognize, namely:

1. The single-sided board which hasconductors on one side only;

2. The double-sided board which hasconductors on both sides; or

3. Multilayer b o a r d s , w h i c h h a v einternal conductor runs and runs on one or bothsides.

The degree of hole support is generallythe hardest to identify because it is often hiddenbeneath the solder. The various styles of support are:

1. No hole support; single-sided board.2. Plated-through hole; single-sided

board.3. Eyelet; single-sided board.4. Plated-through hole; double-sided

board.5. Eyelet; double-sided board.

Component lead termination stylesinclude:

1. Fully clinched lead; a commontype often used in machine soldering as well as handsoldering.

2. Semi-cl inched lead; easier toremove than a fully clinched lead.

3. Straight-through lead; these providethe greatest degree of reliability.

4. Offset pad termination which hasthe hole drilled outside of the pad area.

ORIGINAL 4-7

5. Crimped lead on the componentside, which provides component clearance forimproved solvent cleaning and air circulation. Thisalso provides clearance to prevent components withhigh operating temperature from scorching the circuitboard. (Note that this is NOT a lead termination,but is a component mounting method.)

6. A spaded lead termination in whichthe end of the lead is crimped after being passedthrough the printed circuit board. (Note that thisstyle of termination is easily hidden by the solderand that the lead must be cut between the compo-nent and the spaded portion before attempting toremove the lead from holes.)

7. Lap solder joint lead terminationis a form or style in which the component lead doesnot pass through the circuit board.

4-6.2 IDENTIFICATION METHODS

NOTE

More than one type of solderjo in t connec t ion may befound on a single circuitboard.

1. Welded leads:a. Welded leads have a fine black

line across the component lead.b. Do not attempt to remove this

type of joint. Take to the closest 2M station.2. Use the following means to identify

lead termination style:a. Inspect visually.b. Remove solder from joint to

determine if there are any hidden termination charac-teristics.

3. Use the following means to identifyhole support styles:

a. Inspect visually.b. Carefully remove all solder

from connection to determine hidden hole reinforce-ment characteristics.

4-6.3 RESOLDERING METHODSFOR PRINTED CIRCUITSOLDER JOINTS1. Removal by wicking. Solder

removal by wicking consists of carefully heating thejoint and using finely braided wire soaked in liquidflux. Capillary action draws the solder into the braidsaided by the increased wetting action of the heated flux.

SINGLE+IOED DOUBLE SIDED DOUDLE41DEDPLATEDTHllU HOLE

SOARD TYPES

SINGLE410ED DO&H~&DEYELEITEO

OOUBLE*loEoPLATED TMRU w/EYEL~

EYELETS IN DIFFERENT ~PE BOARDS

uSTRAIGHT-TNROUGH

uFULLY CLINCHED LEAO IN-STALLED IN EYELET

1

mio TERMINATIONS

L-JSEXLINCHED

u uFULLV.CLINCHEO SPAOEO IsIOEI YSPAOE IFRONTI

&jiij!)FUNNEL SET ROLL SET PLAIN PETAL SET

A N Y nYLE EYELETMAV BEOBTAINED IN SOTH HEAD TYPES

EYELET TYPESMAV OE FOUND IN ANY COMBINATION OF HEAD STYLES

(

FiWre 4-2. Typical Types of Circuit Board Lead Terminations

(


2. Manual vacuum extraction. Solderremoval by the manual vacuum method consists of amanually controlled and operated one-shot vacuumsource used in conjunction with heat to create avacuum air flow which pulls molten solder from thejoint. Manual vacuum usually has the advantage ofinstant vacuum rise-time, but may have one or more ofthe following disadvantages:

a. Extremely high vacuum levels,which may cause damage by lifting conductors fromprinted circuit boards, since the conductor bondingmaterial has greatly reduced strength at solder meltingtemperatures.

b. Several applications of thesoldering iron and extractor may be required forcomplete solder removal with the possibility of over-heating the printed circuit board.

c. There may be inability, in somecases, to apply the vacuum tip and the source of heatto the solder joint at the same time.

d. Short duration of vacuum, orphysical movement of the vacuum tip caused bymanual operation of the vacuum source, may causeincomplete solder removal.

4-6.4 SELECTION AND USE OFRESOLDERING TOOLSThe selection of tools and techniques to

be used in a particular resoldering operation will begoverned by the type of solder joint and lead termin-ation. A thorough physical examination must be madeto determine the solder joint characteristics, the mosteffective resoldering technique, and the tools to beused in applying these techniques. The tools andtechniques must be those least likely to cause damageof any nature. To avoid damage, the following factorsshould be considered:

1. Effect on the board materials.2. Effect on circuit conductors.3. Effect on the adjacent components.

NOTE

Testing and evaluation haveshown the following tech-niques have effective andreliable applications. Thetechnician must decide whichtechnique is the best for aspecific task, keeping in mindat all times the requirementof causing no damage.

ORIGINAL 4-9

4-6.5 INFERIOR METHODS OFSOLDER EXTRACTIONSolder removal methods which should

NOT be used or which have limited applications are asfollows:

1. Heat and shake method. This doesnot remove all the solder and causes solder splatter oncircuit board.

2. Heat and pull method. Thehidden lead terminations may cause damage when leadis pulled through the board.

4-6.6 WICKING PROCEDURESThe procedures for wicking solder

removal are as follows:1. Select wicking material which is

smaller than the area being resoldered.2. Spread the wicking with liquid flux

and place it on the area to be resoldered, taking care toensure that there is no overlap of wicking onto theboard material.

3. Apply a clean, heated, dry sol-dering iron tip to the braid using gentle pressure.

4. The wicking may be drawn acrossthe area to be resoldered after the solder melts andbegins to soak into the wicking.

5. If solder stops flowing into thewicking before it has all been removed, or if all the fluxis boiled away, the operation must be repeated aftercutting off the solder-filled portion of the wicking.

6. Better wicking action is afforded asthe number of strands increases and the size of thestrands decreases.

7. Ensure that heat is not excessive.Excessive heatwill boilawaythefluxandcause scorching.

8 . Ensure tha t wicking does notcontact board material. “Measles” (pitting) will resultfrom hot wicking overlapping the pad area and con-tacting board material.

4-6.7 MANUAL SOLDEREXTRACTION PROCEDURESThe procedures for solder removal

using a manual solder extractor are as follows:1. Simultaneously apply the solder-

ing iron tip and the extractor tip to the area to beresoldered. (Note that space may be a limiting factor.)

2. Upon observing a complete soldermelt, press the release trigger which creates a vacuumto extract the solder.

3. Hold extractor firmly to minimizerecoil and give better solder extraction.


4. This manual method may notremove all the solder and may even cause circuit padlifting due to high vacuum generated and movement ofthe extractor tip.

5. To maintain efficient operation,disassemble, clean and lubricate the extractorthoroughly on a regular basis.

4-6.8 COMPONENT REMOVALComponent removal procedures after

solder extraction are as foIlows:1. Straight-through terminations allow

the component to be lifted gently from nonconformalcoated boards.

2. The various clinched-style termina-tions may require the breaking of a sweat joint. Thismay be done by gripping the lead with pliers ortweezers and then rotating the clinched portionapproximately 300 parallel to the board.

3. After breaking the seat joint thelead may be lifted gently to a straight-up position.

NOTE

Do not attempt to lift orstraighten the lead until thesweat joint is broken.

4-6.9 FINAL RESOLDERINGINSPECTIONThe completed work should be in-

spected for damage to the circuit board or to theremaining components. With respect to componentdamage, inspect for cracked, broken, or heated com-ponents; deformed or broken leads; poor solder jointaand loose or splashed solder which may cause shorts.Additional inspection should be conducted for thefollowing damaged conditions:

1. Scorching or charring caused bycomponent failure or improper repair techniques.

2. The appearance of white spotaindicates small areas of the fiberglass strands havebeen exposed by heat, abrasion or solvent action.

3. Possible cracks or breaks in theboard material.

4. Missing pads or conductors.5. Nicked or cracked conductors.6. Lifted or delaminated pads or

conductors.

NOTE

If any of the above conditionsexist, deliver the board to a2M station for repair.

4-1o

4-7 SOLDERING OFWIRE TERMINALS

The most widely used terminals are theturret, hook and tab types. The identification, prepar-ation, and soldering of turret, hook, and tab terminakare described in the following subparagraphs.

4-7.1 TERMINAL TYPES,SIZES, AND USAGESThe three general types of terminrds

(Figures 4-3, 4-4) in common usage are the turret,hook, and tab. Turret terminals can be either singleor multiple sectioned, and are designed to protrudefrom one side of the mounting surface only, orprotrude from both sides (feed-through types). Themost common types of hook terminals used are the“J” style and “?” mark style. The most commonlyused tab terminal is the pierced tab eyelet type. Whenselecting terminals, ensure that the terminal size andconductor or component size are compatible. Con-ductors and components that are too large for a givensize terminal will place an undesirable stress on thatterminal. Turret terminals are used for interracialconnections on printed circuit boards, terminalpoints for pointto-point wiring, for mountingcomponents, and as tie points for interconnectingwiring. Hook and tab terminals are used to provideconnection points on sealed devices and terminalboards. Tab terminals on connector pins are normallymade end-on.

4-7.2 TERMINAL PREPARATIONFOR SOLDERINGPrior to soldering, all terminals must

be thoroughly cleaned to ensure a well-soldered joint.The initial cleaning may be accomplished by addingand then removing excess solder from the terminal.For old, used, or very dirty terminals, some abrasionmay be required to clean completely. Solvent cleaningis required after any of the other cleaning methods iscompleted. After completion of cleaning and prior tosoldering the connection, all terminals must be tinned.

4-7.3 CONDUCTOR PREPARATIONFOR SOLDERINGIn preparing the conductor end for

termination, first determine the length of insulationthat should be removed. Cut the insulation, usingthermal strippers (preferred) or non-adjustable factory-set strippers. Next, using the fingers, slowly removethe piece of cut insulation allowing it to turn andfollow the lay of the conductor strands. Do not changethe rate of twist of conductor strands when removinginsulation. Ensure there is no damage caused by

ORIGINAL

L


WRONG WRONG RIGHTBEND RADIUS

MINIMUM MAXIMUM WRAP MAXIMUM WRAP MINIMUMALLOWABLE FOR #24 ANO FOR #26 AND NORMAL

LARGER SMALLER

BOTTOM WIRE DIRECTLY BELOW

CUT END OF WIRE SHOULD BEEVEN WITH CENTER POST,DEND RADIUS SAME AS RADIUSOF POST (SNUG FIT)

RIGHT WRONG WRONG

WIRE MUST CONTACTPOST IN ALL DIMENSIONS

WILL WET OUT,CONCAVE SOLDERFILLET

//

1’

\\

‘ . — - /

I I m “oEv’EwmuBLE

LFigure 4-3. Turret Terminal Types and Wire Wrappings

O.RIGINAL........- 4-11

SOLDERING TECHNIQUES NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANcE

thi(ii! dI

90.MINIMuMALLOWABLE

RELAY LEAD POSITION

WRONG

g d ~m.-,so

WRONG RIGHT

270*

MAXIMUMALOWABLE

FILLETs

. . . .8EN0 RAOIUS

FO

KECLEa

I ISINGLE

CUT END OF WIRESNOULO ~ EXTENO ,ARALLELTOWRCUTMERE

MYOND PACE OFT E RMINAL

m

l--LOouus

I I

LL

I . .

PREFERRtoINSULATIONOISTANCE v‘\ j;;

;! \\<-- /~+/

WILL WET WTCONCAVE 50LDEFILLET

Figure 4-4. Hook and Tab Terminal Types and Wire Wrappings

4-12 ORIGINAL


L

stripping, such as cuts, nicks, or birdcaging. Any ofthese is cause for rejection. After completion ofstripping, the conductor must be tinned. Tinningis required to prevent damage incurred in the bendingprocess. The use of an antiwicking device is recom-mended to prevent capillary action from pulling solderunder the insulation. When tinning while using theantiwicking device, bring the clean, dry soldering ironin behind the conductor about one-half the distancefrom the antiwicking tool. Next, apply solder to junc-tion of iron and conductor, allowing solder to soakinto conductor strands. Move the iron and soldertoward the antiwicking tool, hesitating just enough toovercome heat-sinking and then move the iron andsolder hack down and off end of conductor. Ifproperly tinned, the individual conductor strands willstill be visible. The tinned conductor end may now bebent or shaped, using any method that does notdamage the conductor in any way. Typical bendingtools are round-nose pliers, nylon rod, orangewoodsticks, and dummy terminals.

4-7.4 ATTACHMENT OFCONDUCTORS TO TERMINALSAttaching the conductor properly to the

terminal prior to soldering is as important as the solder-ing operation itself. Figure 4-3 illustrates both correctand incorrect methods of attaching conductors to turretterminals in preparation for soldering. Figure 4-4 illus-trates both correct and incorrect methods of attachingconductors to hook and tab terminals prior to solder-ing. The following requirements should be followed toensure a good firm connection ready for soldering:

1. On turret terminals, the minimumwire wrap is 180” and the maximum is 2700 forAWG-24 and larger conductors, and 360” for AWG-26and smaIler conductors. The preferred wrap dimensionis 180”.

2. On hook and tab terminals the min-imum wire wrap is 90” with the maximum wrap being2700. The recommended wrap for hook terminals is120”, while the wrap dimension is 180” for tab term-inals. When the wrap is 1200, the wire is not cutstraight across but at an angle to form a flush surfacewith the terminal when installed.

3. The size of the bend shall be suchthat it will tit snuggly against the terminal.

4. On turret terminals, the conductorshould lie flat against the pad.

5. For multiple connections on turretterminrds, all conductors should be wrapped in the samedirection and trimmed to the same length. The conduc-tors should be positioned directly above each other.

ORIGINAL 4-13

6. On hook terminals, the conductorentry should be vertical. On tab terminals, the conduc-tor entry need not be vertical to the terminal mountingsurface.

7. For multiple connections on hookterminals all conductors should approach the terminalfrom the same direction, but the wrap is laid in alter-nating directions. If necessitated by conductor andterminal sizes, the conductors can be piggybacked.

8. The insulation gap shall be nogreater than two times the overlap diameter of theconductor, including the insulation. The preferreddistance is one conductor diameter.

4-7.5 SOLDERING OF CONDUCTORSTO TERMINALSWhen applying heat and solder to the

prepared termination, care shall be taken to preventwicking and damage to the insulation from excessiveheat. When soldering conductors to turret terminrds,the iron should not contact the conductor as it maycause displacement (See Figure 4.5). The majority ofthe heat must be on the pad, with transfer to theconductor through the solder heat bridge. This willalso decrease the chances of wicking. When solderingconductors to hook terminals, the iron must contactthe conductor for heat transfer (see Figure 4-6). Usecare to keep the iron from pushing against the con-ductor and causing misalignment. The completedsolder joint should have adequate solder coveragewithout spillage of solder over sides of the terminaland with the contour of the conductor strands visible.The solder should present a bright shiny surface andthere should be fillets at all points of contact.

4-8 ELECTRICAL WIRE SPLICINGAND HEAT-SHRINK TUBING

Wire splicing is frequently requireddue to poor maintenance practices or poor manu-facturing techniques which allow stress or vibrationto break wires. Three methods for splicing wire arepossible, as shown in Figure 4-7. In some digital typeequipment, splicing cannot be used because it maytend to change conductor characteristics and addnoise to signal. This type of wire must be rerun or aspare wire used. The size of replacement wire andits type of insulation must match the original wire.

4-8.1 TYPES OF SPLICESThe wrap splice is mechanically pre-

pared by laying two tinned wires across each other inan “X” pattern and wrapping them around each other


I 1


[ I

I

Figure 4-5. Turret Terminal Soldering UsingHeat Bridge (Thermrd Linkage)

(

WRONG

Figure 4-6. Hook Terminal Soldering UsingHeat Bridge (Thermal Linkage)

4

several times, using a twisting motion of the fingers.To give proper strength and reliability, both wiresmust twist (not one straight wire with the otherwrapped around it). The twisted portion should betight, with the cut end of the wire flush cut and notprotruding from the splice. The hook splice formsthe strongest mechanical connection. However, it isalso the largest diameter splice, which is often un-desirable. This splice also requires a relatively longsection of tinned wire. The splice is formed by makinga “J” bend in each of the two tinned wire ends, andthen linking the hooks together, with each wire thenwrapped back around itself. The cut end of the wire

4-14

must be flushed+ut, and must not protrude from thesplice. The mesh splice has the smallest diameter andis the most flexible splice, but it unfortunately pro-vides the least mechanical strength. This type of splicedoes not use tinned wires, a fact which is often anadvantage. To form the mechanical connection, thewires are first fanned out into a cone shape. The wiresare then pushed straight into each other so that thestrands interlace evenly and without bunching. Finidly,the wires are gripped gently with the fingers andtwisted in such a manner as to approximate the originalwire lay. (This type of splice cannot be used for doubletwisted wires as the center core of the wire is laidrevemed of the outer strands and therefore will notform the cone shape required.) The solder connectionis also important in making splices. The specificationsare the same as those for soldering any wire, namely:

1 . Smooth concave f i l le ts a t a l lpoints of contact.

2. Bright, shiny surface to the solder.3. Individual strands must be clearly

visible through the solder.4. No wicking.5. No heat darnage to the insulation.

4-8.2 HEAT SHRINK TUBINGThe use of some type of insulation is

mandatory if splicing of a wire leaves an uninsulatedarea. Heat shrink tubing provides the best material forinsulating this area. The size of tubing used should besuch that it will firmly seal over the original insulationwhen fully contracted, but not fit so tight that itwill present a danger of splitting when the wire isflexed. The sleeving must he placed over the wirebefore making the solder connection. The tubingshould never be positioned over the splice area untilthe solder connection has been thoroughly cleaned andinspected. The only reliable method of shrinkingtubing involves the use of hot air since other methods(such as a soldering iron tip or open flame) are verylikely to cause damage. When shrinking tubing, caremust be taken to keep the hot air source moving soas not to concentrate the heat in one place, as thiswould cause the tubing to lose some of its insulatingproperties.

4-9 SO LDERABLECONNECTOR PINS

There are two types of connector pins:solderable type, and crimp type. Crimp type connectorpins shall not be soldered, and solderable type connec-tor pins shall not be crimped. Electrical connector

ORIGINAL


L

STRIP AND TIN

&WRAP

MESH SPLICE

STIP AND SPREAD ENDS WRAP SPLICE

L

WORK ENDS TOGETHER EVENLY

RE-TWISTWORK ENDS IN EVENLY, SMOOTHLY

HOOK SPLICE

BLE TWIST WIREH STRENGTH, FLEXIBLE

CANNOT BE USEO FOR“MESH” SPLICES

Figure 4-7. Wire Splicing Methods

ORI.GINAL 4-15


pins designed for soldering are normally identified bya curve cut-out on one side of the solder cup of thepin, as shown in Figure 4-8. Coaxial connector pinsdesigned for soldering do not have the curved cut-out,but instead have a smafl hole at the base of the soldercup for solder injection. The shape of solderableconnector pins makes cleaning difficult, thereforetinning is the preferred method of cleaning. Aftercleaning, the connector pin should be prefilled byplacing the correct amount of solder in the soldercup so as to form a finished soldered joint. Whenprebilling, ensure that a flux pocket does not existat the bottom of the solder cup. The procedures andrequirements for preparing conductor ends for terminalattachment also apply to connector solder pins. Theconductor insulation should be cut back by using thepin solder cup as a gauge and the clearance betweencut-back insulation and edge of the pin top is oneconductor diameter. Insulated sleeving should beplaced over all soldered pin connections to preventpossible short circuits. Electrical connectors that haveinsulating rings as part of the assembly do not requirethe individual insulating sleeving. Insulated sleevingcannot be used on coaxial connector pins.

4-9.1 SOLDERING REQUIREMENTSThe following requirements are neces-

sary for obtaining quality workmanship when solder-ing electrical connector pins:

1. The conductor must be afignedexactly with the pin cup axis.

2. The conductor must be firmlybottomed in the solder cup to prevent flux or airentrapment.

3. Solder shall not extend beyondthe confines of the solder cup or spill down over thesides of the pin (see Figure 4-8).

4. Edges of the cutaway portion ofthe cup shall be visible beneatb solder, with no portionof the inhmal face of solder cup showing.

5. There shafl be a circular, concave fil-let around the conductor where it enters the solder cup.

6. There shall be no evidence of heatdamage to insulation.

7. There shall be no evidence ofwicking.

8. There shall be a bright shinysurface to the solder.

9. Soldering iron shall be of correctsize and shape to provide sufficient heat.

4-16

4-9.2 APPLICATION OF SOLDERIn connector pin soldering, the tin-

ned conductor is applied to the solder, rather thanapplying the solder to the conductor. The followingsteps are necessary to accomplish a properly solderedpin:

1. Place antiwicking tool on conduc-tor (preferably using antiwicking tweezers).

2. Apply soldering iron and observethe pin for solder melt. Position the iron as low aspossible on solder cup to assure boiling-out of flux andgasses from bottom of cup.

3. Immediately insert the tip of theconductor partially into the solder cup at about 700

angle. Hesitate long enough to allow heat-sinkingaction of the conductor to be overcome.

4. After the solder remelts, veryquickly move the wire to a full vertical position andthen bottom it in the solder cup.

5. Maintain a slight downward pres-sure on the conductor until the soldering iron hasbeen removed and the solder has solidified. This willaid in preventing formation of stress lines in solder.

6. Clean with a bristle brush andsolvent.

7. Apply heat-shrinkable sleeving.

4-1o SOLDERING TOOLSAND CONSUMABLES

Correct soldering iron tip temperatureis important, and can be controlled by varing thevoltage to the iron. This is advisable because, in per-forming high quality work, the tip temperature mustbe proportional to the mass of the piece to be soldered.Also, excessive heat can deteriorate wire insulation ordamage an “eye pad” on a printed circuit card. Com-mercial companies, such as PACE and WELLER, offerseveral voltage control models which can vary the tiptemperature of their irons. If none of these com-mercial controls can be procurred, a voltage-controlledoutlet box, such as depicted in Figure 4-9, can beconstructed by the technician, using the parts listed inTable 4-1 and performing the following steps insequence:

1. Split dark-colored side of recep-tacle (Figure 4-9).

2. Connect black wire from powercord and wire from switch (located on back of pot onvoltage control) to one dark terminal.

ORIGINAL

L

L

L


CONNECTOR CUp

FILLET FILLET

CONCAvESOLDERFLOW

-4zzJ LCOMPLETEDcONNECTOR CUp

IOTE : cONTOUR OF WIRETRANDS NOT VISIBLE


PRE-TI -

sOLDER CUp

PROPER SOLDER CUP TERMINATION

*.~—

IMPROPER SOLDER CUP TERMINATION

Figure 4-8. Electrical Connector Pin Solder Cup

4-17


.— — — — — —— — — — —=/ \

/ ,“–––‘––––––-L’YVARIABLE VOLTAGE \

I [

VOLTAGEC ONT R O L

1 \ ’\\

1 1 FIXED VOLTAG>}WH —— — —— — — ———/

GRN

I / BLK I

SAFETYPLUG

Figure 4-9. Voltage Control for Soldering Iron

Table 4-1. Voltage Control Parts List

ITEM NAME EST. PRICE STOCK NUMBER

Box, Electrical $0.43 5975-00-194-8878Cover, Box, Electrical 0.26 5975-00-281-0053Control, Voltage 5.74 6210-01-035-8680Receptacle, Duplex 0.94 5935-01-012-3080Cord, Power, Three-Wire 1.12 6150-00-431-8027Connector, Box, Electricrd 0.14 5975-00-152-1144Knob 0.44 5355-00-680-1357

3. Connect remaining black wire from 6. Voltage control will cover hole involtage control to remaining dark terminal. plate by moving it to one end of slot.

4. Connect white wire tolightt,errninal. Other recommended soldering tools and5. Connect green wire to ground accessories are listed in Table 4-2. Soldering con-

terminal. sumables are listed in ‘Table 4-3.

4-18 ORIGINAL


L

ITEM

123456789

10

11121314

15161718192021222324252627

FSCM

7182772827

330948134813102131021310219915

19915199151991502105

21325030510305134605346053460502105177948134881348789768134818876

ITEM ] FSCM

1 I2 813483 752974 335915 335916 800637 81348

Table 4-2. Recommended Soldering Tools

REF/DISCR

Clauss #AW-20Clauss #AW-22

613ZZEO061HS1HS2HS3MS54-5

DN-54LN-54RN-543108-s3

DS017SN63-20-1SN63-22-140-1-540-2-540-3-4Paragon 5011121-0131

GGGV41O8000RRC 001409177208-1

REF/DISCR

GGA616154490029005SCB9G203

ITEM NAME

Antiwicking tweezersAntiwicking tweezersBrush, acidDispenser, liquid, 2 oz.Dispenser, SLVTEraser, ink, whiteHeat-sinkHeat-sinkHeat-sinkPliers, dgl ctg, 4 inch(flush cut)Pliers, flt nose, medPliers, lng nose chn, 4-1/2 inchPliers, rnd nose, 4 inchSoldering iron(use advice code 2B)Solder removaf toolSolder, awg 20Solder, awg 22Solder, wick #lSolder, wick #2Solder, wick #3Tip, soldering 1/8 inchTip, soldering 1/12 inchTweezers, CraftsmanVice, work positioningHolder, Soldering IronCash box (tools storage)Wirestnpper, hand

Table 4-3. Consumable Supplies

ITEM NAME

Alcohol, isopropylApplicator-CTN TIPPEDFfux, solderingWiper, disposable (large)Wiper, disposable (smafl)Alignment tool/orangewood sticksHeat-shrink tubing

UI

EAEAGREAEAEAEAEAEAEA

EAEAEAEA

EALBLTEAEAEAEAEAEAEAEAEAEA

STOCK NUMBER

9G 3439-00-954-12699G 3439-00-954-12709Q 7920-00-514-24179L 6520-00-142-9039

9Q 7510-00-634-50359N 5999-00-677-98399N 5999-00-677-98499N 5999-00-677-98619Q 5110-00-596-7164

9Q 5120-00-234-19139Q 5120-00-541-40789Q 5120-00-126-20769G 3439-00-134-9202

9G 3439-00-132-13319QS3439-01-O08-75789QS3439-01-O08-75779G 3439-00-545-33969G 3439-00-403-53219G 3439-00-009-23349G 3439-00-525-73939G 3439-00-149-81979Q 5120-00-293-01499Q 5120-00-991-19079G 3439-00-045-6527

7520-00-281-59315110-00-542-4487

UI STOCK NUMBER

GL 9G 6810-00-286-5435PG 9L 6515-00-303-8250GL 9G 3439-00-752-8728HD 9Q 7920-00-543-6492BX (case) 9Q 7920-00-721-8884EXFT

L

ORIGINAL 4-19/(4-20 Blank)

L

L


SECTION 5

MINIATURE REPAIR

MINIATURE REPAIR

5-1 INTRODUCTION

Tools not ordinarily used in servicingthe conventional wired-circuit chassis are to be usedin servicing a modular assembly or printed circuitboard. Transistors and associated components used inthis type of assembly are extremely small and requirethe use of tools of greatly reduced size in order to copewith the limited space encountered with this type ofconstruction. In addition, special devices which extendthe vision, aid the reach, and sometimes act as a thirdhand are required. Some of the tools required in thistype of repair are shown in Figure 5-1. Many of thesetools may be obtained through the ship’s medical ordental officer. Others, if not carried in the normalsupply system, may be procured tbrough commercialsupply sources. All other tools normrdly required arestandard handtools and are listed in the ElectronicsTools Allowance List. The number of micro-miniaturetools should be held to a minimum compatible withthe actual maintenance needs.

5-2 REMOVING ANDREPLACING PARTS

The removing and replacement of apart without damaging the modular asembly orprinted circuit board and its associated parts requirethat the soldering tool and other handtools requiredbe used with precision and skill. Thought should begiven to the most appropriate procedure or method touse in the removal and replacement of the partinvolved. A part to be removed may be too close to aheat-sensitive semiconductor or other part to allowa hot pencil-soldering iron to be applied. A quick testto determine this safe distance is to place a fingerbetween tbe semiconductor (or heat-sensitive part)and the part to be removed. Place the hot solderingiron in the position it is to be used. If the heat is toogreat for the finger, it is too hot for the semi-conductor. After determining that the heat-sensi-tive parts are too close, place a shield between theparts before applying the hot soldering iron, andplace heat-sink clamps on all leads from the heat-sensitive part. Solid-state parts and their associatedcircuitry are extremely sensitive to thermal (heat)changes. Therefore, particular care must be takento prevent exposing them to heat. Heat-sinks andshunts must be applied with shields inserted to

ORIGINAL 5-1

protect the associated parts any time repair or removalof a part requires the use of a hot soldering iron.Solid-state parts and associated assemblies requirethe same care in handling and skill of repairing that isapplied to assemblies in equipment of unitized or mod-ular construction containing transistors, tantalumcapacitors, crystals, etc. Removal of an axial-leadpart that has been bonded to a printed circuit board(with epoxy resin or similar compound) may beaccomplished by breaking the defective part or byapplying heat to the bonding compound. The methodto use depends upon the part itself and its location.If the defective axial-lead part cannot be removed byheat, cut or break the part away from the bondingcompounds as illustrated in Figure 5-2. “A” and“B” of Figure 5-2 illustrate two different methodsof breaking the part away from the bonding compoundwhere the part is too close to the other parts to usecutting pliers. In some instances, the part to bereplaced is so closely positioned between other partsthat one lead must be cut close to the body of thedefective part to permit application of the pryingtool as illustrated in “A.” Wherever possible, cuttingthe defective part with end-cutting pliers or diagonals,as illustrated in “C, “ is the preferred method to use.Regardless of which tool is employed (round-pointedor spade-type), great care must be used in its appli-cation to prevent the printed circuit board or otherparts from being damaged or broken. Apply the pointof the tool against the bonding compound betweenthe part and the printed circuit board. Use the toolin such a manner that it works away the bonding com-pound from the part to be broken away until enoughhas been removed by the tool to exert pressure againstthe part. Keep the leverage surface area of the toolflat against the surface of the printed circuit board;this helps to prevent the tool from gouging or breakingthe board. BE CAREFUL – NEVER APPLY MUCHPRESSURE AGAINST THE PRINTED-CIRCUITBOARD. After the defective part has been removedfrom the bonding compound, remove the leads ortabs from their terminals on the printed circuit boardand clean the area thoroughly before installing thenew part. Do not remove the bonding compound lefton the board under the removed part unless its con-dition requires it. The mold left in the compoundshould be the same as for the new part; thus, insert-ing the new part in this mold helps secure it fromvibration. Install the new part and, after repairs have

MINIATURE REPAIR

UNGAR UNIVERSAL HANDLE

%

..%.

‘o

INTERCHANGEABLE TIPS

HEATING TIPS

~


THREAD-IN UNITSFOR SUBMINIATURE

SOLDERING

DESOLKXERING UNITS

SOLDER SUCKERATTACHMENT TIP CLEANER

KNIFE END

T W E E Z E R S \ ‘DENTAL PROBE

DRILL ORHOOK A TTACHMENT

SOLDERING AIDS

I SQUEEZE BULB

Figure 5-1. Miniature Tools

5-2 ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 MINIATURE REPAIR

L

A

d?’ Pld IN TO BREAKDEFECTIVE PART AWAYFROM BONOING COMPOUND

,,, I

,/SPADE END

~ A fDs;;~[~;GSCREW DRIVER

COMPOUND

/PUSH IN ANO TWISTTO BREAK DEFECTIVEPART AWAY FROMBONOING COMPOUND

~

CUT OEFECTlvEPART IN TWO -’!iL

-&GoNAL@

PLIERS

.— . —Figure 5-2. Removal of Defective l’arta

been completed and the circuit tested, spray thenewly soldered area with an insulating varnish(MIL-V-1137A or equivalent). Coat the new part orparta with a bonding compound (Epibond by Furane

ORIGINAL 5-3

Plastics or equivalent). To remove a proven defectivetransistor, first cut all of its leads, and then removeit from the assembly. Transistors are mounted oncircuit boards in many different ways; therefore, itis necessary to study how the transistor is mountedbefore attempting to remove it. A transistor withclamp-type mounting requires only a pointed toolbetween the clamp and the transistor to remove it.A transistor mounted in a socket may have a wirespring clamp. Remove the clamp before pulling thetransistor out of its socket. Where the transistor isbolted through the board, remove the nut and washer,and then remove the transistor. Where vibration is aprime factor, the manufacturer will mount the tran-sistor through the circuit board and bond it with epoxyresin or similar compound. For this type of mounting,a flat-ended round-rod-type tool (drift punch) of adiameter less than that of the transistor case isrequired. Before removing the transistor, ensure thatthe printed circuit board, on which the transistor ismounted, is secured in a proper device as illustrated inFigure 5-3 and in such a way that the pressure exertedagainst the circuit board will be relieved by a propersupport on the other side. Apply a hot-pencil solderingiron to the bonding compound and simultaneouslyapply the drift punch against the top of the transistor,exerting enough pressure to remove the transistorfrom the softened compound, and then on through andout of the circuit board as illustrated in Figure 5-3.After the defective transistor has been removed,remove the remaining pieces of the leads from theterminals on the board. Clean and prepare the term-inafs on the board before installing the new part.Before installing a new transistor, great care must betaken to prepare the new part for installation. Testthe transistor in a transistor tester (TS-1100/U orsimilar equipment) before installing. This precautionwill assure that the transistor is good before it isinstalled. Pre-shape and cut the new transistor leadsto the shape and length required for easy replacement.Use sharp cutte= and do not place undue stress on anylead entering the transistor. The leads are fragileand are therefore susceptible to excessive bending ortoo sharp a bend. Shape and bend as required in agradual curve, at least l/4-inch to 3/8-inch from thebase of the transistor. A safety measure which can betaken to ensure that the lead does not break off at thebase is to use two pairs of needle-nose pliers. Grasp thelead close to the transistor base with one pair of pliers,whife shaping the rest of the lead with the other pair.The above procedure and precaution is applicable to

MINIATURE REPAIR NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

r - l

&APPLY HANDPRESSURE

ONLYi

1, (! PENCIL TYPESOLDERING

w \OOWEL PINS

OR REQUIVALENT

Figure 5-3. Transistor Removal

any and all semiconductors, tantalum capacitors, andother miniaturized parts in equipment of modular orunitized construction. Where the defective transistorwas removed from a through-board mounting andbonded, care must be taken that the new transistorclears the hole before it is connected to its terminals.If the hole is too large, shim with a thin plastic sleeve(fabricated). If the hole is too small, ream it to acceptthe new transistor. Rebond the fitted transistor aftertesting the repaired circuit and it is proven to beoperative. DO NOT use heat to rebond semiconductors.To remove and replace a multi-lug part, such as atransformer, choke, filter, or other similar potted,canned or molded part, release the part from itsmounting before disconnecting or cutting its con-ductors. Before applying pressure to remove the part,carefully inspect it to be sure that the part is com-pletely free of all its connections to the printed circuit

5-4

board, and that all bent or twisted mounting lugs havebeen straightened; otherwise, it is possible to break theboard by applying undue pressure to it. Never wrenchor twist a multi-lug part to free it, because this willcause the conducting strip to become unbendedfrom the board. Work this type of part in and outin line with its lugs, as shown in Figure 5-4, whileapplying a hot-pencil soldering iron (using a bar-typetiplet adapter or resoldering tool). Whenever possible,cut the conducting leads and lugs of the defectivemulti-lug part on the mounting side of the board,~ shown in ‘<B>’ of Figure 5-4. Heat and straighten

the clipped leads with a hot-pencil soldering ironand a slotted soldering-aid tool (or slotted solder-ing iron tiplet adapter or similar resoldering tool)applied to the circuit side of the board; then pull theleads or tabs through with pliers as shown in “C”of Figure 5-4. When installing a new multi-lug part,

ORIGINAL


A—

TYPEPLET

auDuWI

B—

CUT WITHDIAGONALCUTTERS

,,

c—

PENCIL TYPESOLDERING IRON

;UT TAB \’.?EMOVEO

NEEDLE NOSEPLIERS

Figure 5-4. Removal of a Multi-Lug Part

be sure that all of the lead holes or slots are free andclean, allowing easy insertion of the part. If the partdoes not position easily, check and rework the term-inals and holes (or slota) until it does seat freely.

ORIGINAL 5-5

DO NOT force any part into position on a printedcircuit board. The board may break or may lift theprinted circuit strip and eyelet terminal. Considerablecare must be taken when replacing a defective partthat terminates on miniaturized standoffs, feedthroughterminals, and such. These small terminals breakeasily from applied pressure (too heavy an applicationwhen applying a tool or soldering iron), or they maymelt loose due to excessive heat produced by pro-longed application of the hot soldering iron.

5-3 SPECIAL SOLDERINGTECHNIQUES

Replacement of miniature and submin-iature parts found in modular assemblies requires moreconsideration than is normally given to parts in theservicing of other electronic equipment. Beforeattempting repair, maintenance personnel shouldbecome thoroughly familiar with the correct repairand soldering techniques, since servicing proceduresused differ in a number of ways. The compactness ofmodular assemblies makes it imperative that a small,low-wattage pencil iron be used. The soldering ironshould have a small tip so that heat can be applieddirectly to the terminal of the part to be removed orreplaced, without overheating the printed circuitboard or adjacent parts. practical soldering irons,with tips specially designed for soldering and un-soldering parts from printed circuit boards, have beendeveloped by a number of companies. The off-set orstraight-slotted tiplets will simultaneously melt thesolder and straighten the leads, tabs, and small wiresbent against the board or terminal. The bar tiplet willremove straight-line multiterminal parts quickly andefficiently. The cup-shaped tiplets, the triangle tiplet,and the hollow-cube tiplet are specially designed towithdraw solder from circular or triangular mountedparts in one operation. The most important require-ment for repairing modular assemblies and printedcircuit boards is for skill in the soldering and unsolder-ing of parts. Careless work creates damage. Take timeand be precise. When applying solder, remember thatthe iron must heat the metal to solder-melting temper-ature before actual soldering can take place. Thesolder-melting temperature is reached in a matterof seconds (5 to 10 seconds); therefore, the solderingiron and the solder strand must be applied simultan-eously. Make certain to apply the solder to the joint,wire, or contact to be soldered, not to the solderingiron. Before applying any solder to a part be surethat the terminal, or any portion of the part to besoldered, is properly cleaned and tinned before


positioning it for soldering. Do not tin printed circuitterminals; just clean any moisture, grease, or wax fromthe printed ribbon with a stiff-bristle brush and methylchloroform or alcohol. Be sure the cleaning solvent hasdried before applying the hot soldering iron.

CAUTION

Alcohol is flammable. Methylchloroform is not flammable,but heating it increases itstoxic hazard.

Use methyl chloroform only with ade-quate ventilation and avoid prolonged or repeatedbreathing of its vapor or contact with the skin.

5-4 PRINTED CIRCUIT ANDMICROELECTRONICSTECHNIQUES

Because printed circuits are small andcompact, it is essential that maintenance personnelbecome familiar with the special servicing techniquesrequired for this type of repair. In all instances, it isadvisable to first check the defective printed circuitbefore beginning work on it to determine whetherany prior servicing has been performed. Not all per-sonnel having access to this type of equipment havethe skill and dexterity required; hence, some preli-minary service may be necessary. Observing this pre-caution may save a great deal of time and labor. Thedefective part should be pin-pointed by a study ofthe symptoms and by careful and patient analysis ofthe circuit before attempting to trace trouble on aprinted circuit board. It must be ascertained whetherthe lands (conducting strips) are coated withia pro-tective lacquer, epoxy resin, or similar substance. Ifany of these protective coatings have been applied,they must be removed and the surface must be prop-erly cleaned before corrective maintenance can beperformed on the equipment.

5-4.1 REMOVAL ANDREPLACEMENT OFPROTECTIVE COATINGSMany manufacturers of equipments

used by the Navy apply protective coatings (also calledconformal coatings) to their equipment. Theseprotective coatings include epoxies, silicones,polyurethane, varnishes and lacquers. Most of the

5-6

coatings consist of a synthetic resin dissolved in avolatile solvent. When properly applied to a cleansurface, the solvent evaporates, leaving a continuouslayer of solid resins. After curing, this coating protectsagainst environmental stress, corrosion, moisture, andfungus. These protective coatings may be removed bychemical or mechanical means. The application ofchemical solventa is not recommended, however, asthey may cause damage to the printed circuit boardsby dissolving tbe adhesive materials that bond thecircuits to the boards. These solvents may also dissolvethe potting compounds used on other parts or assem-blies. Most polyurethane protective coatings can beremoved by applying heat to the area to be cleaned,then gently scraping the coating with an X-acto knife.Detailed procedures for the removal and replacementof conformal coatings by this method and the toolsand materials required are given in the following sub-sections.54.1.1 Tools and Materials

The tools and materials in the follow-ing list are required to remove and replace protectivecoatings. The FSN or manufacturer’s part number isgiven in Table 5-1.

Printed circuit card holderTeflon tapeSoldering ironBrush, nylonX-acto knifeCotton swabsAlcohol, isopropyl3X, 4X, and 12X viewersPolyurethane coating or

epoxy-resin compound

5-4.1.2 Removal of Protective CoatingTo remove the protective coating from

the printed circuit board the following procedure isrecommended:

1. Place the printed circuit boardin the card holder as shown in Figure 5-5.

2. Mask the area that is not to bestripped of the protective coating with Teflon tapeas shown in the figure.

CAUTION

Excessive heat may damagethe printed circuit board orsurrounding parts.

ORIGINAL


Table 5-1. Tools and Materials for Parts Removals

L

FSN or Manufactured byItem Quantity Mfg. Part No. or Equivalent

Part 1– Required Tools

Ungar Universal Handle 1 ’777 UngarThread-in Element, 23-1/2 Watts 1 535 UngarThread-in Element, 37-1/2 Watts 1 1235 UngarThread-in Element, 47-1/2 Watts 1 4045 UngarPencil Tip 1 PL331 UngarPencil Offset Tip 1 PL332 UngarChisel Tip, Long Taper 1 PL333 UngarTapered Needle Tip 1 PL338 UngarStepped Pencil Tip 1 7154 UngarUngar Hot-Knife Tip 1 4025 UngarOffset Slotted Tip 1 862 UngarStraight Slotted Tip 1 857 UngarHollow Cube Tip 1 863 UngarCup Tip, 5/8” Dia. 1 856 UngarCup Tip, 3/4” Dia. 1 855 UngarCup Tip, 1“ Dia. 1 854 UngarDesoldenng Tip (DIP) 1 859 UngarDesoldenng and Cleaning Tool 1 7800 UngarSoldering Iron Holder 1 8000 UngarKleen-Tip Sponge and Tray 1 400 UngarLow-Voltage Soldering Iron 1 6970 UngarPrinted Circuit Card Holder 1 371 Henry Mann Co.Steel Bench Clamp 1 356 Henry Mann Co.Miniature Vise 1 353 Henry Mann Co.Illuminated Magnifier, 3 Power 1 LFM-1 Henry Mann Co.Clip-on Lens, 4 Power 1 No. 1 Henry Mann Co.Desoldenng and Cleaning Tip, 0.33” 1 7812 UngarHemostat 1 8-907 Fisher Scientific Co.Hand Tool - lead trimmer

(TO type package) 1 Henry Mann Co.Resoldering and Cleaning Tip, 0.057” 1 7806 UngarDesoldenng and Cleaning Tip, 0.069” 1 7813 UngarHigh-Intensity Lamp 1 5975 TensorLead-Forming Tool 1 ATH-3260 Astro Tool Co.DIP Package Puller 1 6982 Ungar45 ‘Chain-Nose-Tip Cutter 1 A119 Henry Mann Co.Toothpicks, Round 1 BoxWooden Dowels, 1/4” x 6“ 10Triceps Tweezer, 8“ 1 T8 Henry Mann Co.

L

ORIGINAL 5-7


Table 5-1. Tools and Materials for Parts Removals - Continued

FSN or Manufactured byItem Quantity Mfg. Part No. or Equivalent

Part II – Required Materials

Insulating Varnish 1 pt 5970-280-4920Epoxy-Resin Compound 1 Kit 8040-777-0631Potting Syringes 12 E-602 FishmanEpibond 1 Kit H-1331 Furane PlasticsAcid Brushes 12Solvent Dispensers 4 613 Henry Mann Co.Polyurethane Coating 1 Kit CE-1155 Conap, Inc.Isopropyl Alcohol 1 pt TT-1-735Methyl-Ethyl Ketone 1 pt ‘IT-M-261Acetone 1 qt 6810-281-1864Copper Shim Stock .003”Aluminum Oxide Abrasive Paper 10 Shts/Box 5350-967-5080Cotton Swabs Johnson & JohnsonTeflon Tape - 1“ 1 Roll

Figure 5-5. Printed Circuit Card Holder

4

3. Heat a small area of the coating tobe removed by holding a soldering iron close to thesurface, but do not touch the board with the iron.

5

CAUTION

Do not apply excessive pres-sure during scraping as thismay cause nicks on the landsof the board or damage to theleads of other parts.

4. When the protective coatingsoftens, gently scrape it away from the surfacewith an X-acto knife.

5. Remove loosened particles of pro-tective coating by gently brushing. Assure that looseparticles of coating do not contaminate any movingparts.

6. Repeat steps 3 through 5 untilall coating has heen removed from the area exposedby the mask.

7. Cleanse the area with a cotton swabthat haa been dipped in alcohol to remove all looseparticles of protective coating that remain afterbrushing.

8. Remove the mask and clean thearea with a cotton swab and alcohol to ensure that noloose particles of coating remain on the perimeter ofthe stripped area.

9. Using a 12X viewer, visuallyexamine the cleansed area to assure that the area isclean and that no darnage was done during the clean-ing operation.

-8 ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-OO-Ell’>q -160 MINIATURE REPAIR

L

L

5-4.1.3 Replacement ofProtective CoatingTo replace the protective conformal

coating on the printed circuit board the followingprocedure is recommended:

CAUTION

Protective coatings may affectthe capacitance (air dielectriccapacitance between leads)and the Q of inductors inRF assemblies. Refer to theappropriate maintenance pro-cedures in the equipmenttechnical manual concerningalignment procedures andthe proper use of protectivecoatings for RF assemblies.

1. Using a 12X viewer, visually inspectthe repaired board for foreign particles.

2. Clean area to be coated with acotton swab that has been dipped in alcohol.

3. Allow the printed circuit boardto dry thoroughly. Drying time will depend on thecleansing agent used (alcohol is recommended).

4. Mask the area that is not to becoated as shown in Figure 5-5. The unmssked areashould be large enough to rdlow some overlapping withthe old coating to assure adequate protection.

5. Spray the exposed area with threelayers of protective coating material, allowing suffi-cient time for curing between successive coats. Severalthin coats are more effective than one heavy coat.If the coating material has a tendency to porosity,it is unlikely that the pinholes will occur in exactlythe same positions on successive coats.

6. Remove the mask and inspect thereworked area, using a 12X viewer, for any voids orpinholes. If any voids or pinholes are observed, addanother coat of protective coating.

5-4.2 REPAIR OF PRINTEDCIRCUIT BOARDSPrinted circuit assembly wiring patterns

are formed in three basic ways: by painting, chemicaldeposit, and as stamped or etched metal foil. Shipboardrepair of painted and chemically deposited printedwir ing pa t te rns i s not recommended becausethe necessary specialized equipment is not alwaysavailable. The metal foil printed wiring patterns consistof a thin metal foil bonded to a nonconductive base.The wiring pattern is produced by stamping the foilbefore bonding it to the base, or by chemically etching

ORIGINAL 5-9

away unwanted portions of the metal foil after bondingto the base. Because metal foil is the most readilyrepairable and most commonly used type of printedwiring board, the repair techniques described in thesubsection apply to metal foil printed circuits only.The major cause of printed circuit board failuresattributable to maintenance actions is mishandlingduring fault isolation and replacement ofparts. It is important, therefore, that care be exer-cised in performing maintenance. After isolation of afault to a printed circuit board, the board should bevisually examined to determine the possible cause ofthe fault. If the cause is not readily apparent, the landson the boards should be checked for continuity, usingan ohmmeter and needle probes. Place the probes ateach end of the land. If the land is open, remove oneprobe along the board until continuity is observedon the meter. Then locate the break in the landwith the aid of a 12X viewer. The three major typesof circuit failures are caused by cracks, voids, orpeeling of the lands. During the visual examination,it may be observed that the copper laminate used forthe contact fingers has separated or peeled away fromthe board. This type of damage can be repaired byfollowing the procedures described in the followingsubsections.

5-4.3 VOID REPAIRSTo repair a void in a land, the following

procedure may be used:1. If the land has been covered with a

conformal coating, remove it in accordance with theprocedure outlined in 5-4.1 above.

2. Using an X-acto knife, trim eachend of the broken land at a 45-degree angle as shownin Figure 5-6(a). Ensure that the remaining end of eachland is firmly attached to the board.

3. Strip the insulation from a smallpiece of AWG 22 hook-up wire. Lay the stripped wireon the board and solder as shown in Figure 5-6(b).

CAUTION

Excessive heat may cause theends of the conductor to liftfrom the board.

4. Clean the soldered areas withcotton swabs that have been dipped in alcohol.

5. Using a 3X viewer, visually inspectthe area for solder flux and solder splashes and removeany residue.

6 Check repaired area for continuity.7. Replace the conforrnal coating as

described in 5-4.1 above.


REMOVE ENDS

\.A./( ,

LAND

45° 450

1

!\

PCB

(a)

(b)

Figure 5-6. Void Repair Procedure

4

5-4.4 LANDS REPAIRSTo repair cracked lands, the following

procedure may be used:1. If the land has been covered with

a conforrmd coating, remove it in accordance with theprocedure outlined in 5-4.1 above.

2. Flow-solder the cracked sectionstogetber as shown in Figurw 5-7.

5-1o

CAUTION

Ensure that solder does notflow over the edges of the landas this will reduce the spacingbetween lands and affect theelectrical performance char-acteristics of the board.

ORIGINAL

b tl’d tK/+L WIA+IIN I CINAIVUE l\H V>EA >Evuu-uu-r I WI- I vu

SOLDERINGIRON

IVI I IV IM I u n E n =r MI n

\

CONDUCTORSTRIP

\

SOLDER

/ ’PCB CRACK TO BE

REPAIRED

Figure 5-7. Lands Repair Procedure

3. Clean all residue from the boardwith a cotton swab that has been dipped in alcohol.

4. Using a 3X viewer, visually inspectthe area for solder flux and solder splashes and removeany residue.

5. Replace the conformal coating asdescribed in 5-4.1 above.

5-4.5 PEELED CONDUCTORSTo repair peeled conductors, the follow-

ing procedure may be used.1. If the land has been covered with a

conformal coating, remove it in accordance with theprocedure outlined above.

2. Using an X-acto knife, trim each endof the land at a 45-degree angle. Ensure that the remain-ing end of each land is firmly attached to the board.

3. Use a length of AWG 22 hook-upwire with teflon insulation that will span the void inthe conductor. Strip both ends and tin.

4. Position the wire as shown inFigure 5-8 and solder ends to terminals.

ORIGINAL 5-11

5. Pot the wire togeneral-purpose adhesive to preventhandling of the board.

the board withbreakage during

6. Using a 3X viewer, visurdly inspectthe area for solder flux and solder splashes and removeany residue.

7. Check for continuity.8. Replace the conformal coating as

described in 5-4.1 above.

5-4.6 LOOSE CONNECTOR TABSThe repair of loose connector tabs may

be done in the following manner:1. Place the edge of an X-acto knife

between the board and the loose tab, lifting tab asshown in Figure 5-9.

CAUTION

Do not allow the tab to curlor form right-angle bends asthis will damage the tab.


PEELED LAND

PEELED LAND

STRIP END ANDSOLDER TOTERMINAL

Figure 5-8. Peeled Conductor Repair

4

d

4

2. Place a piece of teflon on the toppart of the tab and clean the underside of the tabwith aluminum oxide sandpaper until it is a brightcopper color.

3. Remove all old adhesive fromthe board by gently scraping with an X-acto knife.

4. Gently wipe the underside of thetab and board with cotton swabs that have beendipped in acetone.

CAUTION

Acetone is flammable,

5. Using potting syringe, apply ad-hesive to the tab and board surfaces.

5-12

6. Place teflon on top of the taband clamp both to the board with a “C” clamp, asshown in Figure 5-9(a).

CAUTION

Do not move teflon orrotate clamp while tighteningclamp. Such movement mayresult in improper orientationof the tab.

7. Allow adhesive to cure in accor-dance with the manufacturer’s specifications.

8. Remove clamp and teflon.9. Gently scrape the board with an

X-acto knife to remove excess adhesive.10. Clean tab by wiping with a cotton

swab that has heen dipped in acetone.11. Assure that” the repaired contact

fits into the connector.12. Check continuity.

5-4.7 BROKEN CONNECTOR TABSThe repair of broken connector tabs

may be done in the following manner:1. Using an X-acto knife, cut off the

rough edge of the broken tab by making a 45-degreeangle cut as shown in Figure 5-9(c).

2. Ensure that the undamaged sectionof the tab is still bonded to the board.

3. Clean the board by scraping off anyresidue and wipe with a cotton swab that has beendipped in acetone.

4. Cut a replacement cwntact from apiece of copper foil stock 0.002-inch thick of the samedimensions as the tab to be replaced, allowing l/4-inchfor a lap-joint at the point of contact with the existingcopper land.

5. Clean the replacement contact byhoMing it with tweezers and dipping in acetone. Placethe cleaned contact on a clean piece of paper.

6. Using the potting syringe, prepareadhesive in accordance with manufacturer’s directionsand apply to the board.

7. Using tweezers, align the replace-ment contact and press flat.

8. Using an X-acto knife, scrape offexcess adhesive, leaving a thin film on the board.

9. Place a piece of teflon over thereplaced tab and clamp with a “C” clamp as shownin Figure 5-9(d).

ORIGINAL

L

L


CAUTION

Do not move teflon or rotateclamp while tightening. Suchmovement may result in im-proper orientation of the tab.

10. Allow adhesive to cure in accor-dance with the manufactumr’s specification. Todecrease curing time, place a lamp (60 to 100 watts)approximately 5 inches from the board.

11. Remove clamp and teflon.12. Solder at the point of overlap

between the new and original circuitry, using aminiature low-voltage soldering iron.

13. Using a smrdl, flat file, bevel theedge of the tab at a 45-degree angle to conform to thebevel of the board, as shown in Figure 5-9(e).

14. Gently scrape the board with anX-acto knife to remove excess adhesive.

15. Clean contact and solder joint bywiping with cotton swabs that have been dipped inalcohol.

16. Assure that the repaired contactmates evenly with the proper connector.

17. Check continuity.

5-4.8 REMOVAL ANDREPLACEMENTOF FLAT PACKSBecause of their small size, extreme

care must be exercised in soldering and unsolderingflat-pack leads. Careless work may cause damage tothe mounting surfaces and/or the circuits. Orienta-tion of the flat pack with respect to the mountingsurface is also of major importance. Afl flat packshave index points, usurdly located in one corner oron the package centerline. Before removing any flatpack, the board to which it is attached should bemarked or a sketch made of the location of the indexpoint so that the replacement device may be properlyoriented as shown in Figure 5-10.5-4.8.1 Tools and Materials

The tools and materials in the follow-ing list are required to remove and replace flat packs.The FSN or manufacturer’s part numbers are given inTable 5-1.

45-degree chain nose tip cutterDesoldenng and cleaning tool (solder sucker)Low-voltage soldering ironSolder suckerX-acto knifePrinted circuit card holder

Teflon tapeEpoxy resin compound3X, 4X, and 12X viewersAlcohol, IsopropylCotton swabsTricep tweezersLead cutting and forming tool

(or wooden form)Potting syringe

5-4.8.2 Removal and Replacementof Soldering-In Flat PacksUpon completion of subsystem check-

out and the localization of the defective flat pack,the following removal and replacement procedure isrecommended:

1. Insert the printed circuit boardin the card holder with the flat pack face up, as shownin Figure 5-10.

CAUTION

Solvents and abrasives maydamage the board or sur-rounding parts and are notrecommended for shipboardmaintenance. They should beused only under controlledconditions.

2. If the flat pack has been coveredwith a conformal coating, remove the coating inaccordance with procedures given in 5-4.1 above.

3. Mark board to show the location ofthe index mark on the flat pack, as shown in Figure 5-10.

4. Using a pair of sharp chain nosetip cutters, cut the flat pack leads hrdfway betweenthe soldered joints and the body of the flat pack,as shown in Figure 5-10.

5. If thermally conductive adhesivehas been used between the flat pack and the board,hold the device with tricep tweezers and place theheated blade of an X-acto knife between the flat packand the printed circuit board on one side of the flatpack and gently move the knife back and forth in acutting motion. Repeat this process on all four sidesuntil the flat pack has been loosened.

CAUTION

Do not tap board to removeexcessive solder as this maycause bridging of lands onother parts of the board.


LOOSE CONNECTOR TABI

(a)

CUT HERE

— —

— DAMAGED TAB

(b)

f \

CONNECTOR

\ / Im \/ 133~KEMENT

“C” CLAMP

(d)

‘jEDGE BEVELEDAT 45° SOLDERED

~ /

OVERLAP

{

DAkW3ED TAB

\pcB

(c)

Figure 5-9. Peeled Connector Tab Repair/Replacement

5-14

(e)

ORIGINAL


INDEX MARKALTERNATE INDEXMARK

\ 111

I i I-r Ol-r

t

1

I

t

1

-i t-1 I

t JJ J

MARK ON BOARDCORRESPONDINGTO DEVICEINDEX MARK

45° CHAIN NOSETIP CUTTERS

Figure 5-10. Removal and Replacement of Flat Packs

6. Unsolder the remaining leads, oneat a time, using a resoldering iron and solder suckerattachment to remove excess solder.

7 . Af ter removing the f la t pack,remove mask and visually examine the printed cir-cuit board with a 12X viewer. Remove all residue(conformal coating, solder flux, and solder splashes)and clean the board with a cotton swab that bas beendipped in alcohoL

CAUTION

Assure that cleaning solventhas dried before applying ahot soldering iron. Alcoholis flammable.

8. Examine the replacement devicefor signs of damage. Review applicable circuit specifi-cations and test circuit in accordance with the appli-cable technical manual.

9. Remove the flat pack from thehandling container. If a suitable lead cutting andforming tool is not available, place the flat pack ona wooden form and cut the leads to the proper length,one at a time, with a sharp X-acto knife, as shown inFigure 5-11.

ORIGINAL 5-15

CAUTION

Make certain that the replace-ment flat pack circuit isproperly oriented withrespect to the index markprwiously scr ibed on theprinted circuit board. Incor-rect positioning of the pack-age will result in destructionof the circuit and have adeleterious effect on systemperformance.

10. Using the potting syringe, applyepoxy resin compound to the underside of the flatpack and place the package in position, using tnceptweezers.

11. Allow the adhesive to cure inaccordance with the manufacturer’s requirements.

CAUTION

Use a miniature low-voltagesoldering iron. Excessive heatwill damage the flat pack and/or the printed circuit board.


Figure 5-11. Flat Pack Lead Cutting Procedure

12. Flow-solder the flat pack leads tothe board, one at a time, using a miniature low-voltagesoldering iron, as shown in Figure 5-12.

13. Using a 12X viewer , v isual lyexamine the area surrounding the replaced device forbad solder joints, bridging of solder between the leads,flux residue, or excessive adhesive.

14. Clean all residue from the leadsand printed circuit board, using a cotton swab that hasbeen dipped in alcohol.

15. Place the printed circuit boardin the system, if the system is available, for finaltest and checkout. If the system is not available,the proper inputs should be duplicated in accor-dance with specified test procedures and the outputmonitored using bench test equipment and proce-dures described in the appropriate equipment test andcheckout manual.

16. Replace conformal coating as de-scribed in 5-4.1 above.

5-

5-4.8.3 Removal and Replacementof Welded-In Flat PacksWelded-In flat packs are removed and

replaced by following the procedure given forSoldered-In flat packs except that the portions of theleads remaining on the printed circuit board, afterremoval of the package, are clipped as closely aspossible to the welded joint to facilitate the solderingof the lapped joint of the replacement leads.

5-4.9 REMOVAL ANDREPLACEMENT OF DIPsBecause of their smallness, extreme care

must be exercised in soldering and unsoldering DIPleads. Careless work may damage the mounting surfaceand/or circuits. Orientation of the DIP with respectto the mounting surface is also of major importance.All DIPs have index points, usually located in onecorner or on the package centerline. Before movingany DIP, the board to which it is attached should be

16

L

L

MINIATURE REPAIR

/

SOLDERING IRON

1/4” LAP SOLDER JOINT

L

FLAT PACK LEAD

~ FLAT PACK


~pcEj

LAND 2

Figure 5-12. Flow Soldering Technique

L

45-degree chain nose tip cutterResoldering and cleaning tool

(solder sucker)Low-voltage soldering ironSolder sucker attachmentX-acto knifePrinted circuit card holderTeflon tapeEpoxy resin compound3X, 4X, and 12X viewersAlcohol, isopropylCotton swabsTweezem, straightInsulating varnishDIP package pullerToothpicks

marked or a sketch made of the location of the indexpoint so that the replacement device may be properlyoriented, as shown in Figure 5-13.5-4.9.1 Tools and Materials

The tools and materials in the followinglist are required to remove and replace DIPs. TheFSN or manufacturer’s part numbers are given in Table5-1.

ORIGINAL 5-1

5-4.9.2 Removal and Replacementof DIPs on Boards WithConformal CoatingUpon comple t ion of subsystem

checkout and localization of the defective DIP, thefollowing removal and replacement procedure isrecommended:

1. Insert the printed circuitboard in the card holder as shown in Figure5-3.

2 . Construct a tef lon tape maskover the circuit board, exposing the DIP to beremoved as shown in Figure 5-3 and remove con-formal coating in accordance with procedure given in5-4.1 above.

3. Mark board or make a sketchindicating location of the index mark on theDIP.

4. Using a pair of 45-degree chainnose tip cutters, cut the package. leads, one at a time,as shown in Figure 5-14(1).

5. Lift the portion of the leadsattached to the package, one at a time, withtweezers, bending the leads upward, as shown inFigure 5-14(2).

7

MINIATURE

DIP

REPAIR

INDEX

NAVSEA SEOOO-00-EI M-1 60

MARK

\ MARK ON PCB

\ Al

GENERAL MAINTENANCE

CAUTION

.4?%

Figure 5-13. DIP Orientation for Repair

c) CUT

@ :X&ATED@ ::~HEADs

TO LOOSENCONFORMAL TWEEZERSCOATING ANDREMOVE DIP

\,..$.q+l~yy#

( b )

Figure 5-14. DIP Lead and Coating Details

5-18

Do not apply a prying or lift-motion with the X-acto knifeas th is may damage theprinted circuit board.

6. Using a heated X-acto knife blade,loosen the conformrd coating beneath the package andgently lift the package.

7. Remove conformal coating remain-ing on the board in accordance with the procedurepreviously described.

8. Remove solder from each leadremaining in the board, using a soldering iron andsolder sucker and heater. Simultaneously removeleads with tweezers.

9. Clean holes in the printed circuitboard, using a toothpick.

10. Remove all residue (conforrnaJ coat-ing, solder flux, and solder splashes) and clean boardwith a cotton swab that has been dipped in alcohol.

11. Examine the replacement device forsigns of damage. Review the applicable circuit speci-fication and test circuit in accordance with applicabletechnical manual.

12. Upon satisfactory completion ofthe visual and electrical tests, align the circuit pins.

CAUTION

Assure that the circuit isproperly oriented. Improperpositioning of the packagemay result in destruction ofthe circuit and have a dele-ter ious effect on systemperformance.

13. Insert DIP in the board and solderleads individurdly, using low-voltage soldering iron.

14. Using a 12X viewer, visually inspectthe area surrounding the replaced device for badsolder jointa, bridging of solder between leads, andflux residue.

15. Clean all leads andsurroundingareaswith a cotton swab that has been dipped in alcohol.

16. Place the printed circuit board inthe system, if the system is available, for final test andcheckout. If the system is not available, the properinputa should be duplicated and the outputs monitoredusing bench test equipment and procedures in theappropriate equipment test and checkout manual.


L

L

L

,., ,,‘,

.

5-4.9.3 Removal and Replacementof DIPs on Boards WithoutConformal CoatingUpon completion of subsystem check-

out and localization of the defective DIP, the followingremoval and replacement procedure is recommended:

1. Mark the printed circuit board orsketch the location of the index mark on the DIP.

2. Heat the solder at each lead, indi-vidwdly, and remove the molten solder from top ofboard with a solder sucker or wicking tool.

CAUTION

Do not apply twisting orprying forces as this maydamage the printed circuitboard or break DIP pinswithin the board.

3. Using a DIP package puller, illus-trated in Figure 5-15, grasp the DIP as shown. Heat allleads simultaneously, using the solder sucker attach-ment. Gently pull the DIP away from and perpendic-ular to the board. The DIP should be easily freed fromthe printed circuit board.

4. Clean holes in the printed circuitboard, using a toothpick.

5. Remove all residue (solder flux andsolder splashes) and clean board with a cotton swabthat has been dipped in alcohol.

6. Examine the replacement device forsigns of damage. Review the applicable circuit specifi-cation and test circuit in accordance with the appli-cable technical manual.

7. Upon completion of the visual andelectrical tests, align the circuit pins.

CAUTION

Assure that the circuit isproperly oriented. Improperpositioning of the packagemay result in destruction ofthe circuit and have a dele-terious effect on systemperformance.

8. Insert DIP in the board and solderleads individually, using low-voltage soldering iron.

9. Using a 12X viewer, visually inspectthe area surrounding the replaced device for bad solderjoints, bridging of solder between leads, and flux residue.

ORIGINAL 5-1

Figure 5-15. DIP Package Puller

10. Clean all leads and surroundingareas with a cotton swab that has been dipped inalcohol.

11. Place the printed circuit boardin the system, if the system is available, for final testand checkout. If the system is not available, theproper inputs should be duplicated and outputs mon-itored using bench test equipment and proceduresin the appropriate equipment test and checkoutmanual.

5-4.10 REMOVAL ANDREPLACEMENT OFTO-TYPE PACKAGESThe TO-type packages containing inte-

grated circuits are available with 8 to 12 leads. Theleads are usually arranged in a symmetrical pattern

9

MINIATURE REPAIR NAVSEA SEOOO-00-E 1 M-160 GENERAL MAINTENANCE

d

-

and mounted directly to lands on the printed circuitboard. Two of the most common mounting techniquesare the embedded and the plug-in. The procedurescurrently used to remove and replace transistor TOpackages are also applicable to modified TO packagescontaining integrated circuits. The major differencebetween the two packages is that the number of leadson modified TOS is greater and the space betweenleads is less than on standard TOS, thus limiting thespace available for lead clipping, resoldering, andsoldering. The smaller packages also require greatermanual dexterity on the part of repair personnel.Other constraints, such as spacing of lands on theprinted circuit board, removal of conformrd coatingsand such, present additional problems to the mainte-nance technician. Protective conformal coatingscontribute to the difficulty in unsoldering leads,removing devices from the mounting surface, andpreparing the mounting surface for device replacement.Subsection 5-4.1 of this handbook contains procedureson removal and replacement of conformal coatings.After the protective coating has been removed, deviceleads must he disconnected and the device removed,but the procedure to be followed in removing the TOwill depend on the mounting configuration. If thepackage to he removed is embedded or plugged inwithout a spacer, the leads should be clipped and thepackage removed before those segments of the leadsremaining in the board are unsoldered. If this is notpossible (as would be the case with packages thatare flush mounted or plugged-in with a spacer) allleads should be heated simultaneously to allow packageremoval. Procedures for removing embedded, plug-in,and flush-mounted packages are given in the followingsubsections. Replacement TO circuits should be elec-trically tested in accordance with the applicabledetailed specifications and subsystem operatingrequirements.5-4.10.1 Tools and Materials

The tools and materials in the followinglist are required to remove and replace TOS. The FSNor manufacturer’s part numbers are given in Table 5-1.

Teflon tapeResoldering and cleaning tool

(solder sucker)Low-voltage soldering iron45-degree chain nose tip cutterLong-nose pliersPrinted circuit card holderToothpickHemostatAlcohol, isopropyl

5-20

Cut tipCotton swabs3X, 4X, and 12X viewers

5-4.10.2 Removal and Replacementof Embedded TOS and TOSWithout SpacersUpon comple t ion of subsystem

checkout and localization of the defective TO, thefollowing removal and replacement procedure isrecommended:

1. Place the printed circuit board inthe card holder as shown in Figure 5-16. If the boardhas been covered with a conforrmd coating, maskall portions of the board except for the TO thatis to he removed.

CAUTION

Excessive heat may damaget h e T O p a c k a g e a n d / o rprinted circuit board.

2. Remove coating from the terminalareas and area where the package is inserted into theboard. This can best be accomplished by holding asoldering iron close to the board and gently scrapingthe conformal coating with an X-acto knife.

3. Using a 45-degree chain nose tipcutter, clip the leads near the TO package.

4. Apply pressure to top of TO pack-age with a wooden dowel to remove TO from theboard, as shown in Figure 5-16.

5. Heat terminals with a resolderingiron and remove molten solder with a solder suckerattachment.

CAUTION

Do not forcibly pull or applytwisting motion to leads.This may damage terminals.

6. Remove those segments of leadsremaining in the board by applying the resolderingiron to the land on the board and gently pull down-ward on the lead, using long-nose pliers.

CAUTION

Wait until alcohol has driedbefore using soldering iron.Alcohol is flammable.

ORIGINAL


b

L

Figure 5-16. TO R

8

CLIP LEADS

PUSH OUT TO-5 WITH DOWEL

~ UNSOLDER LEADS

~ PULL OUT LEAD ENDS WITHLONG-NOSE PLIERS

7. Clean all terminal areas with acotton swab that has been dipped in alcohol.

8. Using ,a 12X viewer, inspect termi-nals for loose solder, solder flux residue, and damageto terminals.

9. Visually examine replacementdevice for damage; review applicable circuit specifica-tion; and test replacement circuit in accordance withrequirements of the appropriate operational specifica-tion and MILSTD-883.

10. Align leads and insert tested TOpackage into the printed circuit board.

11. Solder leads individually with aminiature low-voltage soldering iron, using long-nosepliers as a heat sink.

12. Inspect repaired area with a 12Xviewer and remove any solder splashes or foreignmaterials with a cotton swab that has been dippedin alcohol.

13 . I f requi red by the equipmentmaintenance manual, apply conformrd coating inaccordance with details in 5-4.1 above.

ORIGINAL 5

emoval Procedure

14. Place the repaired printed circuitboard in the system, if the system is available, for finaltest and checkout. If the system is not available, theproper inputs should be duplicated and the outputsmonitored using bench test equipment and followingprocedures in the appropriate equipment test andcheckout manual.5-4.10.3 Removal and Replacement

of Flush-Mounted TOS andPlugged-In TOS With SpacersUpon comple t ion of subsystem

checkout and localization of the defective TO, thefollowing removal and replacement procedure isrecommended:

1. Place the printed circuit boardin the cad holder, as shown in Figure 5-5. If theboard is covered with a conformrd coating, mask allportions of the board except for the TO that is to beremoved.

2. Heat each lead individually andremove molten solder from the board with the soldersucker attachment.

-21


=- HEMOSTAT

, T O P A C K A G E1 - (

T

\ PCB\

CUP-TYPE TIPLET

(7F?, SOLDERING IRON

l-J

Figure 5-17, Resoldering Iron WithCup-Type Tiplet Adapter

CAUTION

Do not apply twisting motionto TO package. This maydamage the printed circuitboard or terminals.

3. Heat all leads simultaneously withthe cup-type tiplet adapter to the resoldering iron asshown in Figure 5-17. Using hemostats, gently graspthe package and remove from the printed circuitboard.

CAUTION

Wait until alcohol has driedbefore using soldering iron.Alcohol is flammable.

4. Clean rdl terminal areas with acotton swab that has been dipped in alcohol.

5. Using a 12X viewer, inspect terrn-imds for loose solder, solder flux residue, and damageto terminals.

6. Visually examine replacementdevice for signs of damage. Review applicable circuitspecifications and test circuit in accordance withrequirements of the appropriate operational specifi-cation and MIL-STD-883.

7. Align leads and insert new TOpackage in printed circuit board.

CAUTION

Excessive heat may destroythe terminrd or the replace-ment circuit.

8. Solder leads, one at a time, usinga miniature low-voltage soldering iron.

9. Using a 12X viewer, inspect therepaired area and remove any solder splashes or foreignmaterials with a cotton swab that has been dippedin alcohol.

10. If required by the applicable equip-ment maintenance manual, apply conformrd coatingin accordance with subsection 5-4.1 above.

11. Place the printed circuit board inthe system, if the system is available, for final testand checkout. If the system is not available, the properinputs should be duplicated and the outputs monitoredusing bench test equipment and following procedures inthe appropriate equipment test and checkout manual.

5-22 ORIGINAL

.— - ----- . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . ---- . . - -. . . . . . . . . . - .-- .-. . ..,. . . -. . . . . . . . . . . ,. . . . . . . . . . . . . . . . .--- . .—. . . . . .

SECTION 6

MICROMINIATURE REPAIR

L

L

6-1 INTRODUCTION

The complexity of modem militaryelectronics systems has made the use of micro-electroniccircuits a necessity. The widespread use of such micro.circuits has given rise to a major maintenance problem.The average electronics technician can no longer employthe familiar basic hand tools to effect microminiaturerepairs. The technician must now learn how to useentirely new repair techniques and specialized tools.The term “micro-electronics” refers to that area ofelectronics technology associated with extremely smallcomponents. Micro-electronics includes extremely smallcircuits having a high equivalent circuit density, and areconsidered as a single part or entity, composed ofinterconnected elements mounted on a single substrateand designed to perform a specific electronic circuitfunction. This technology includes all types of “FlatPacks,” “Dips,” and “TOS.” Micro repair proceduresinclude all techniques covered in the miniature repairsection of this publication including, but not restrictedto, the following component repair and installation:

1. multilayer printed circuit boards2. small, complex, and very dense

printed circuit boards3. flexible printed circuit boards4. installation of special connectom,

eyelets and terminals.

Repairs to such entities may involve electroplatingtechniques, microsoldenng (using a stereo microscope),and/or the complete rebuilding of a printed circuitboard (PCB) (refer to Table 6-1 on microminiaturetools and equipment for repair of electronic equipment).

6-2 REMOVING AND REPLACINGMICROMINIATURE PARTS

One of the major problems in the repairof electronic assemblies and modules is the removal andreplacement of coatings that were applied during originrdmanufacture. Use of the terminology “Coatings,” insome instances, is erroneous since the thickness of thecoating that some manufacturers apply is well beyondthe point that could normally be considered a coating.There are several basic ways in which liquids that havebeen formed into a flexible plastic (rigid, solid or

ORIGINAL 6-1

foamed state) are used to support, seal and insulateelectronic parts, sub-modules, modules and assemblies.Some of these are defined as:

1. Impregnation – A method usedfor sealing porous materials, securing coil windings andother parts. Impregnation is accomplished by spraying,dipping or vacuum processing with very thin liquids.

2. Encapsulation – The process ofcoating the surface of an object with a viscous materialto establish a continuous thick protective layer whichusually conforms to the shape of the object beingencapsulated.

3. Potting – When a part and its con-tainer or housing are made integral by filling the con-tainer with a material which sets-up so as to preventshifting of the part within the container. Potting alsoprevents the entry of moisture or dirt.

4 . Embedding – This is similar toPotting except that the container is a temporary moldwhich is removed after the material sets-up.

5. Coat ing – A relatively thin pro-tective layer which covers the surfaces of the objectand is sometimes referred to as a “ConformaI Coating. ”

The following procedures will be concerned primarilywith coating and encapsulation in the repair ofmodules, since the potting and embedding techniquesare usually associated with items requiring less frequentrepair. Both the coating and encapsulation techniquescan be combined into the overall category of coatings,since the basic differences between them is thickness.

6-2.1 REASONS FOR COATINGCoatings are used for various protective

and functional purposes including: humidity, fungus,mechanical shock and vibration, electncd insulation,mechanical pentration and abrasion, heat sinking andbonding. To meet the specific usage for one or moreof these reasons, the coating material selected by themanufacturer may require the following characteristics:

1. Good thermal conductivity to carryheat away from the components.

2. Low shrinkage factors during appli-cation and cure to prevent the coating from applyingstrains or stresses to the components, their leads ortheir serds.

MICROMINIATURE REPAIR NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

Table 6-1. Tools and Equipment Microminiature Electronic Repair

Microminiature Tools and Equipment for repair of electronic equipment – 2M Microminiature Repair ProgramSupport Equipment/Tools are to be provided only to those activities that have a minimum of two properly trained

and certified personnel on board

FSCM

(81343 )GGA616(81343 )GGBO0821

(81343 )GGBO0821

(81343 )GGBO0521

(81348)GGBO0821

(81348)GGBO0821

(81348)GGBO080(81348) GGHO080

(81348)GGHO080(81348) GGH80

(02105)105146(02105)105143

[81348) HBO064-3TYPE2CL1SZ1

(17794 )SX11O-81[17794)1127-0002[18037 )BR-416

[89630)E112

[81348) 11BO0681[17794 )SX11O-83

[17794)1127-006

[08807) 15R14SC/FL

:08807 )15R14SC/SP:81348) GGBO0821:81348)GGBO0821

:81348)GGBO0821

:81348)GGBO0821:81348)GGBO0821

:18037)11-4/0

:81348) GGBO0821:81348)GGBO0821:81348) GGBO0821

“81348)GGBO0821

“81348)GGBO01275

Item Name

Applicator, Disposable

Ball Mill, No. 2Ball Mill, No. 4

Ball Mill, No. 6

Ball Mill, No. 8

Ball Mill, No. 1/2

Blade, Surgical Knife, Sz. 11Blade, Surgical Knife, Sz. 15

Blade, Surgical Knife, Sz. 20Blade, Surgical Knife, Sz. 25

Blade, Thermrd Scraper, ShortBlade, Thermal Scraper, LongBrush, Acid Swabbing

Brush, Bristle

Brush, Dental

Brush, Replacement

Brush, TypewriterBrush, Wire

Bulb, Flood

Bulb, SpotBurr, Ball, Latch, #1/2

Burr, Ball, Latch, #2

Burr, Ball, Latch, #4

Burr, Ball, Latch, #6Burr, Ball, Latch, #8

Burr, Dental #1/4 (Straight Handpiece)

Burr, Inverted Cone, #33-1/2Burr, Inverted Cone, #35

Burr, Inverted Cone, #37

Burr, Inverted Cone, *9Burr, Needlepoint, Interproximal

NSN

9L 6515003038250

9L 65200100322699L 65200100322709L 6520010032271

9L 6520010033131

9L 6520010033132

9L 6515006600010

9L 6516006600008

9L 65150004419219L 6515002998055

9G 34390104503169G 34390104503159Q 7920005142417

9Q 7920000187052

9L

9Q 5120010288462

9Q 75100055084469Q 7920000187091

9G 6240010291113

9G 6240010295988

9L 65200050330009L 6520010032274

9L 65200100322759L 6520010037703

9L 6520010032276

9L

9L 65200050410009L 65200100322729L 6520010035346

9L 65200100322739L 6520002999677

4

6-2 ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 MICROMINIATURE REPAIR

L Table 6-1. Tools and Equipment Microminiature Electronic Repair (Continued)

FSCM

(18037)R-4/O(81349)MILB36179(27552) 101-OOOA(81348)GGCO01265(81348)GGCO01265(81348)GGCO01265(81348)GGCO01265(17794)1265-0003(19204)12000647-15(81348)GGT555(75206)520(19204)7540802(81348)GGCO01433(81348)GGCO01433(81348)GGCO01433(81348)GGCO01433(81348) QQC576(81348) QQC576(19915)GA54(81348)GGPO0468(75347 )D209-5C(30879 )1127AS200(81348)GGDO0426(81349)MILD36456(81349)MILD36256(81349)MILD36256(33092)613NOREF(81348)GGD751[17794)6010-0013[19204)12000647-16(04347)0151(81348)ZZEO0661(89630)E111(73685)812(81348)GGEO0916(81348)GGEO0916(04264)CME36B(04264 )CME44

Item Name

Burr, Round, Latch Type, #1/4Burr, Trimming, RoundCable, FlexCarver, Cleoid, Discoid No. 89-92Carver, Hollenback #1/2Carver, Hollenback #3Carver, Tanner No. 5TChamber, Solder Extractor

Chest, Tool

Chisel, Dental, Black #81

Chisel, Dental, Black #84Chisel, Dental, Black #36Chisel, Wedelstaedt #42Copper Foil .004Copper Sheet .005Cutters, Angled, FlushCutters, Diagonal

Dies, Eyeletting, Sizes 2,3, and 4 (set)Disc, Abrasive, Silicon CarbideDisc, Abrasive, 150 GritDisc, Abrasive, 280 GritDisc, Abrasive, 80 GritDispenser, AlcoholDispenser, Liquid, 2. oz.Drill, Long No. 30Element, Solder Extractor

Epoxy Resin, SyntheticEraser, Rubber, PencilEraser, FiberglassEraser, Ink, BlockExplorer, No. 6Explorer, No. 23EyeletEyelet

NSN

9L 65200093572499L 6520000768683IRW513001 024 5071TX9L 65200093572549L 65200093571519L 65200051154509L 65200093572529G 3439001498190

9Q 5140003195079

9L 65200053639059L 65200053640259L 65200053641259L 65200051515509Z 95350026895719Z 95350050671019Q 51100076448019Q 5110005421350

9L 65200052321509L 65200022605719L 65200022605739L 65200022605769G 34390055293099L 65200014290399Q 51330059588509G 3439008081806

9Z 80400006183039Q 75100063450359Q 51200102842859Q 75100028128019L 65200052800009L 65200052810009Z 53250105772569Z 5325010308486

L

ORIGINAL 6-3


Table 6-1. Tools and Equipment Microminiature Electronic Repair (Continued)

FSCM

(04264 )CME33(04264 )CME23(81349MILF36733(81348)GGGF331TYPE18CL1T0 12(24123 )AA928(75297)1544

(24123 )AA932

(81348)GGG531

(81348)GGHO080(81349) GGHO080

(30879 )1127 AS162

(02105)105142

(30879 )1127AS161

(30879)02611-1(27552) 555CA

(30879) 1127 AS160

(30879 )02610-1(27552)79D

(30879) 1127AS156

(30879) 02605-1(27552)330

(30879 )1127 AS1O5

(30879) 02604-1(17794 )SX200(13102)HS1(18876)11066463-001

[13102)HS2(13102)HS3[18876)11066463-003[24123 )AA935A

[08292)K24M

[08807)308338[06175)31-26-18

[81348)GGMOO1O8

[81348) GGMOO1O8(11915 )MS54-5:19915 )DN-54:50172) PL281

Item Name

EyeletEyeletFile, Bone, Seldin No. 11

File Set, NeedleFilter, Felt

Flux, Rosin

Gasket, Pump Filter

Goggle, IndustrialHandle, Surgical Knife #4

Handle, Surgical Knife, Sz. 9Hand Piece, Thermal Scraper/

Lap flow SolderingHandpiece, Rotary Drive,

Contra-Angle

Handpiece, Rotary Drive, Flexible

Handpiece, Rotary Drive, Large

Handpiece, Solder Extractor

Heat Sink

Heat Sink

Heat Sink

Jar, Filter

Kit, Tool, Miniature, No. XK24MLamp, Drill PressLens, 0.5X Supplementary

Mandrel, Screwtype, 64 T.P.I. Latch

for Cutting DiscMandrel, Straight for Cutting DiscPliem, Diagonal Cutting, FlushPliers, DuckbillPliers, Duckbill, Microminiature

NSN

9Z 53250009765279Z 53250102908169L 6520005285050

9Q 51100020426859C 43100088253369G 3439007528728

9Z 5310002914104

9G 4240000423776

9L 65150034478209L 6515003447920

9G 34390104503171RM513001 0207944 TX

1RM513001 0207943 TX

1RM513001 0245073 TX

9G 34390080821449N 5999006779839

9N 59990067798499N 5999006779861

9C 43100086955909Q 51800005298859G 62400075635249 0 6 7 6 0 0 0 9 9 9 3 5 6 79L 6520009268845

9L 65200092688469QS511O 0095865079Q 51200192809379QM512001 0287102

4

6-4 ORIGINAL



FSCM

(81348)GGP471TYPE11 CL1STYLEB(19915 )LN-54(81348) GGPO0471

(50172)PL286(19915 )RN-54(50172) PL291

(81348) GGPO01278

(81348)GGP831

(81348) GGGP831

(79687)1400

(81348)GGGS278TYPE2CL6

(O21O5)375Q

(17794 )SX1.75-61 “(81348) DDM440

(81348) QQS571(81348) QQS571

(81348) QQS571

(02105) 3108-S3

(34605 )40-1-5

(34605)40-2-5

(02105 )40-3-5(81348) GGSO0590

(30119)45-181

(02105)10517(81349 )MILT23594

(17794)1121-0213(17794)1121-0214(17794)1121-0215

(17794)1121-0217

(02105)105147(17794)1121-0131

(O21O5)PARAGON5O3(O21O5)PARAGON5O1(O21O5)PARAGON51O

(02105)105134

(02105)10542(02105)10529(80063)SCB98203

(81348) GGT870TYPE4CL1STYLE1

Item Name

Pliers, Long Nose

Pliers, MuIt. Tongue and Groove

Pliers, Needlenose, MicrominiaturePliers, Round NosePliers, Round Nose, Microminiature

Plugger, Woodson No. 2

Punch Drive Pin, 1/4”

Punch, Drive Pin, 5/32”

Respirator, DustScissors, Electricians

Screw, Set, S.S. Slotted, Short

Seal, Rear, Solder ExtractorSlab, Dental Mixing

Solder, Eutectic, AWG-22 (.025)Solder, Eutectic, AWG-20 (.032)

Solder, Multicore, Eutectic, AWG-28 (.013)

Soldering Iron, 25-WattSolder Wick #l

Solder Wick #2

Solder Wick #3Spatula, Dental No. 324Stripper, Wire, Mechanical

Stripper, Wire, ThermalTape, Insulating, TeflonTip, Extractor .018”Tip, Extractor .025”Tip, Extractor .036”

Tip, Extractor .061”Tip, Lapflow Soldering

Tip, Soldering Iron,Chisel 1/16”

Tip, Soldering Iron, Chisel 1/8”

Tip, Soldering Iron, Cone

Tip, Tweezers, Resistance, Micromin.Tips, Resistance Soldering

Tips, Thermal Wire StripperTool, Alignment, Elect. Equipt.Tweezers, Curved Point, Smooth

NSN

9Q 5120005414078

9Q 51200027803509Q9QS5120 0012620769QM512001 0274907

9L 6520005365405

9Q 5120002406083

9Q 5120002406104

9Q 51100025504209Z 5305010290653

9G 34390001425579L 65200055620009G 3439002013866

9C 3439007703949

9G 34390077042339G 3439001349202

9G 3439005453396

9G 3439004035321

9G 34390000923349L 65200055680009Q 5110007683797

9Q 51200102871429G 59700081273879G

9G 3439001477258

9G 3439001498197

9G 34390052573939G 3439001498196

9GS343901 03757739G 34390104457499GS343901 03724959Q 51200029320819Q 5120002889685

ORIGINAL 6-5



FSCM Item Name NSN—

(02105)10541 Tweezers, Resistance Heating 9G 3439004063047(71827 )AWG20 Tweezers, Antiwicking 9Q 5120009541269(71827)AWG22 Tweezers, Antiwicking 9Q 5120009541270(71827 )AWG24 Tweezers, Antiwicking 9Q 5120009541272(71827) AWG28 Tweezers, Antiwicking 9Q 5120009541276(02105)105133 Tweezers, Resistance, Micromin. 9Q 5120010287145(81348)GGGT870TYPE5CL2 Tweezers, Self-Locking 9Q 5120002930149(81348)GGGV41O Vise, Work Positioner 9Q 5120009911907(81348)GGW239 Wheel, Abrasive, Ball, 1/8” 9L 6520005468000(17794)1129-0008 Wheel, Abrasive, Bullet, Coarse 9Q 5130001723418(86297)8C(86297)8XF Wheel, Abrasive, Bullet, Extra Fine 9Q 5130001650929(17794)1129-0007 Wheel, Abrasive, Bullet, Fine 9G 3460002251955(86297)8F(81348)GGW239 Wheel, Abrasive, Doughnut, 1/4” x 3/32” 9L 6520002034620(81348)GGW239 Wheel, Abrasive, Knife Edge 3/16” 9L 6520005477160(86297)5XF Wbeel, Abrasive, Knife Edge, Ext. Fine, 1“ 9Q(86297)SF Wheel, Abrasive, Knife Edge, Fine, 1“ 9Q(81348)GGWO0253 Wheel, Abrasive, Rubber 7/8” x 1/8” 9L 6520005686150(81348)GGWO0253 Wheel, Abrasive, Rubber, Knife Edge 3/8” 9L 6520005231115(81348) GGWO0253 Wheel, Abrasive, Rubber, Knife Edge 5/8” 9L 6520005231120(81348)GGW239 Wheel, Abrasive, Tapered Cyl. 3/32” x 1/4” 9L 6520005480010(81348)GGW239 Wheel, Abrasive, Square Edge 3/8” x 1/16” 9L 6520005483010

REPAIR STATION MAJOR ASSEMBLIES

(30879) 1127AS1OO Solder Extractor Unit 6RX513001 0241482 TX(30879) 1127AS124 Tool Chest 6RX513001 0273418 TX(30879) 1127AS125 Power Supply-Hand Tool 6RX613001 0258811 TX(30879) 1127AS141 Mechanical Drive Unit 6RX513001 037 8695TX(30879) 1127AS158 Work Handling System IRM494000 9148427(30879) 1127 AS164 Optical Magnifier IRM6650 01025 8803TX(55055)221217 Lamp, High Intensity 9G623001 0332081

ANCILLARY EQUIPMENT

(30879) 1127AS165 Drill Press – Eltr Pwr Sup 6RX513001 0241677 TX(30879 )1127 AS166 Microscope – Stero Zoom 6RX665000 8977051 FA(30879) 1127AS167 Plating System 6RX513001 0241493 TX(30879) 1127AS168 Drill Press – Eltr 6RX513001 0258105 TX

6-6 ORIGINAL


L

L

3. Resilience, hardness and strengthcharacteristics to properly support and protect thecomponents to meet their loading conditions.

4. Low moisture absorption.5. Inorganic materials so as not to feed

fungus growth, etc.6. Electrical insulation qualities.7. Other characteristics, as required.

6-2.2 TYPES OF COATINGSThe general types of electronics coating

materials in present day use include:

1. Varnishes2. Two-Part Epoxies3. Polyurethane4. Acrylic Lacquers5. Silicone Varnishes6. Various types of Room Temperature

Vulcanizing (RTV) Silicone Rubbers.

The primary methods for applying these coatingmaterials include: brush on, spray on, dipping, andspread or pour on. The particular method of applyingthe coating is a primary factor for determining the thick-ness and uniformity of coating in the end product.Dipping and pouring of coatings wilI result in relativelythick coatings. Spraying and bmshing will usually resultin thin coatings. One of the great paradoxes in the useof coatings is that the type and extent of coating usedwill vary from manufacturer to manufacturer. Somemanufacturers whose equipment is used in the sameelectronics system and environmentrd location may notuse any coatings at all. The question which then arisesis why any coating was selected and used by a givenmanufacturer? It all seems to be related to the preroga-tives of the original designer and manufacturer and hisspecific technical analysis. Conformance to specificationmay also be a factor. It will be found that in someassemblies only one side of the board is coated. Hereagain, the designer may reason that certain penetra-tion or abrasion conditions may occur and relate to oneside only, or that the mechanical stability of the com-ponent side of the board is critical and, therefore, astabilizing coating must be used on that side. To assurethe continuity of a coating used for electrical insulationor moisture resistance over a given surface, some pro-ducers include a tracer in the coating material itself.Thus, ultra-violet light detection will indicate an}7 dis-continuities of surface coverage. Specifications on theinspection of coatings, as defined by various manufac-turers, may run the full extreme from allowing air

ORIGINAL 6-7

bubbles and pin holes within the coating, as determinedby inspection under a source of ultra violet light. Theextent to which this inspection is earned out is usuallydictated by the individual producer. It is of interestto note that some producers make their coatings opaque.Transparent or translucent coatings would permit therepairman to observe what is below the coating. Thisis not possible with opaque coatings,

6-2.3 IDENTIFICATION OF COATINGWhen a complete set of drawings and

technical data is made available from a given manufac-turer, and assuming he has used the same coatings onall his assemblies, the technician would thus be aware ofthe coating used on a specific assembly. However, insome cases a manufacturer may inconsistently use asmany as four or five different kinds of coatings. Thisresults in never knowing for sure which particularcoating was used on the specific assembly at hand.Under such circumstances it becomes valuable toestablish a uniform means for identifying any varietyof coating that may be used on any module. Certainphysical characteristics are available to establish coatingidentification (refer to Table 6-2):

1. Is the coating hard or soft, orsome place in between?

NOTE

This may be determinedby a penetration-type test,simply pushing a pointedobject against the coatedsurface.

2. Is the coating opaque, transparentor translucent?

3. Is the coating thick or thin? Thecriteria for thick or thin is nominally established as.010 to .015 being a thin coating, and anything overthat thickness as being a thick coating. Thick orthin determinations are related to the methods ofremoval, as described in another section of thisdocument.

4 . The volubi l i ty of the coat ingmaterhd is another characteristic that may be identi-fied. Almost all coating materials are soluble in somesolvent. The problem is to assure that the solventwhich removes or breaks down the coating will notdarnage the circuit board or its associated componentparts. The very nature of solvent removrd techniques

MICROMINIATURE REPAIR

Coating I Hard ] Soft

AcrylicLacquer

EpoxyResin

VarnishSilicone

VarnishPoly-uRTV

x

xx

.x— L

———xxx


Table 6-2. Identification of Coatings

Thick Thin Transparent

x x x

x x x— x —

x x xx x xx — —

Translucent

—

—x

——x

GENERAL MAINTENANCE

Opaque

—

xx

——x

Soluble

x

——

x——

Strippable

——

—

x

NOTE: Identifiable characteristics are relative and not absolute; i.e., gradations from hard to soft can exist for manycoating materials; variations from transpwent to opaque may exist in the same coating, etc.

COLOR OF COATINGS

NOTE: Color variations by addition of tracer dyes (ultra-violet indicators, etc.) and fillers can provide a wide varietyof coloration in the same coating material.

Acrylic Lacquer Clear - may have dye tracers.Epoxy Resin Clear - Amber - may be opaque by dyeing and fillers.Varnish A m b e r - B r o w n .Silicone Varnish Clear - may have dye tracers.Poly-u Clear - may have dye tracers.RTV Translucent to Opaque - may also be colored.

also relates to whether all the coating is to be removedor whether only spot-removaf is required for a givenrepair. Coating removal by solvent is described inthe “Coatings” section of this manual.

5. One other criteria for coating identi-fication is its “stoppability.” A classification of coatingscalled “stnppable” is cafled out in MIL specifications.Removal of this (strippabIe) type of coating shouldmerely require “slitting through” and peeling it off thesurfaces, leaving the clean surface behind. Unfortu-nately, this type of coating is extremely rare since oneof the primary criteria for the selection of a given coat-ing is that it act as a heat sink, thus requiring it toconduct heat from the component part into the base-board and atmosphere. If the coating is stnppable,it can be inferred that either an air space, pcmr adhesion,or a release agent film exists between the coating andthe work surfaces, thus creating a thenmd barrier. Thisresults in a contradiction that if the coating isstrippable, it would not be as effective a heat sink asone that is not stnppable.

6-8

6-2.3.1 Relative Hardness of CoatingsThe relative hardness or softness of a

coating can be determined by a simple penetrationtest using a pointed instrument applied to the surfaceof the coating in a non-critical area.6-2.3.2 Transparency of Coatings

A coating may be transparent,translucent or opaque. Means of determining this isobvious, and its importance relates to not only aid inidentifying the coating but indicates a factor in diffi-culty of removal. An opaque coating does not permitobservations of underlying elements during coatingremovaf, hence, placing such items in jeopardy.6-2.3.3 Thickness of Coatings

The relative thickness of a coating can bedetermined by visual means. A thin coating will showvery sharp outlines of the components and almost nofillet at points of intersection of part leads to circuitboard. Thick coatings, conversely, reduce the sharpoutlines of components and show discernible tlletsat points of part or lead intersections with board.

ORIGINAL


L

6-2.3.4 Volubility of CoatingsMost all coatings are soluble; however,

the solvent required to dissolve the specific coating mayafso attack the board and/or the components. Therefore,the volubility test and use of solvents should be limitedto using only xylene and trichlorethane or equal. Testthe coating with either of these materiafs in a non-cnticaf area by brushing on a smafl quantity of thesolvent and observe the volubility action.6-2.3.5 Strippability of Coatings

The stoppability of a particular coatingcan be determined by carefully splitting the coatingwith a sharp blade in a non-critical area, and thenpeeling the coating from the module surface. It shouldbe noted that so-called strippable coatings are nottruly strippable due to their intrinsic adhesion quali-ties and entrapment under part leads. Adhesion quafi-ties are essential in selecting coating materials in orderto provide heat dissipation characteristics.6-2.3.6 Comparing Coating Characteristics

Table 6-2 listed the various physicalcharacteristics associated with the generic types ofcoatings. Note that in many cases the difference in onlyone distinctive characteristic will distinguish one coatingfrom another.

6-2.4 COATING REMOVAL METHODSOnce the specific type of coating has

been generally identified, the appropriate removafmethod can be employed. The need to remove all theconformal coating from the connections to be un-soldered (and resoldered) is based first on the fact thatunless it is removed, it creates a heat barrier whichmakes it difficult to melt solder joints. Second, the

Material

Acrylic LacquerPoly UrethaneEpoxy ResinSilicone Rubber (RTV)VarnishSilicone Varnish

* Hard type only.

Table 6-3. Coating R

ThermalParting

xx

x

MechanicaAbrasion

xx

**X

*x

** Freon TF used to soften and expand.

ORIGINAL 6-9

conformal coating may cause solder joint contaminationwhen resoldering. The better a board is cleaned ofcoating at the beginning of a replacement procedure,the easier it will be to restore the board to a serviceablecondition. In most instances, only a spot-removzd ofthe coating is necessary to suit the required repairaction. There may be a few cases where removal of afl ofa specific type of coating, by solvent means, can beperformed on a production basis as easily as spot-removal. Five coating removal methods are recom-mended: 1) solvent, 2) stripping, 3) thermal parting,4) abrasion, 5) hot jet. Tbe specific removal methodto be employed is based on: 1) the generaJ type ofcoating, 2) the specific condition of the coating, and3) the critical nature of the parts and the circuit board.Table 6-3 relates coating material type to its recom-mended removal method. It should be noted that insome cases two or three removaf methods are shownfor a single coating type since variations in coatingconditions require such diversity.6-2.4.1 Solvent Method

Mild solvents, such as xylene or trichlor-thane (or equal) may be used to remove specific soluble-type coatings on a spot basis by brushing or swabbingthe local area a number of times, using fresh solventuntiI the area is free of coating. If warranted, afl of asoluble-type coating can be removed from the assemblyby immersing and brushing the entire circuit board whileimmersed in a series of tanks containing mild solvent,starting with a high contamination tank and progressingsequentially to a final, fresh solvent tank. Alternately,a single step means for removing all coating may beutilized by providing a continuous flow of fresh mildsolvent with a flow-off of contaminated solvent.

emoval Methods

lSolvent

x

x

x

Hot Jet

xx

x

MICROMINIATURE REPAIR NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANcE

CAUTION

In using the solvent methoddetermination must be on amodule-by-module basis, ofhazards to parts, etc., byshort-term immersion in, orent rapment of , solvents.Rapid solvent dry-off throughforced evaporation, as wellas neutralization, if required,should be utilized.

CAUTION

Chloride-based or other harshsolvent must not be utilized.Extreme care must be exer-cised to prevent damage tobase laminates and component parts.

When removing RTV materials (primarily by stripping)a pre-soak in Freon TF will soften and expand the RTV,thus permitting a simplified stripping procedure.6-2.4.2 Procedure for Solvent Removal

1. To remove solvent, dip the end of acotton-tipped applicator in the solvent and apply asmall amount to the coating around the soldered con-nections of part to be replaced. Because various sub-stances have been used as conformal coatings, the timerequired for a given coating to dissolve will vary. Repeatthis step several times, as the solvent evaporates veryreadily.

2. Rub the treated surface carefullywith a bristle brush or the wood end of the applicatorto help dislodge the conformal coating.

3. Abrade the exposed solder connec-tions and brush away the residue.

6-2.4.3 Stripping Method

{

Stripping is practical only under spe alcircumstances. For example, in removing RTV sili ematerials, a pre-soak in freon TF will soften and ex andthe RTV silicone. This will loosen the bond between theboard and RTV, which can then easily be slit and peeledoff.6-2.4.4 Thermal Parting Method

“Thermal parting” employs a controlled,low temperature, localized heating method for removingthick coatings by over-curing or softening. This method

6-10

permits the removal of any thick coating material fromwork surfaces, as well as the release of bonds betweencomponent parts and circuit boards. Various shapedtemperature-controlled tips, without sharp edges, areavailable in a variety of configurations to suit workpieceaccess. The thermal parting method does not bum orchar either the coating or circuit board.

CAUTION

Do not use soldering irons forcoating removal as their highoperating temperatures willcause the coatings to char, aswell as possibly delaminatethe board materials. The useof thinned-down solderingtips or solder-iron-heated thincutting blades are not recom-mended since they do notprovide controlled heating orsufficient capacity. They alsopresent dangerously sharpedges to the workpiecesurface.

6-2.4.4.1 Thermal Parting Procedure

1. To separate a coating, first selectan appropriate thermal parting tip to suit the work-piece configuration. Set the nominal tip tempera-ture, using the manufacturer’s recommended pro-cedure.

2. Apply the thermal parting tip to thecoating, using a light pressure. The coating mater-ial will either soften or granulate (Epoxy coating willgranulate and Poly-U will soften.) The tip temperatureshould be regulated to a point where it will effectively“break down” the coating but without scorching orcharring.

3. The coating thickness around thecomponent body should be gradually reduced withoutcontacting the board surface. As much coating as pos-sible should be removed from around component leadsto allow easy removal of the leads. Pre-clip leads ofcomponent parts that are known to be faulty shouldbe pre-clipped, thus permitting removal of the partbody separately from leads and solder joints. Lowpressure air or a bristle brush should be used to removewaste material during the parting process. This willallow good visual access and inhibit inadvertent damageto the board.

ORIGINAL


4. With only a smafl bonded jointbetween the part body and board, heat the comp~nent body with the thermal parting unit or smafl solder-ing iron to weaken the bond beneath the component.Lift the component body free of the circuit board.

5. Once the component body has beenremoved from the board surface, the remaining coatingmaterial can be removed by additional thermal partingor by the miniature machining abrasive method. Theremaining leads and solder joints are then removed asdescribed in the “Parts Removaf” section.6-2.4.5 Mechanical Abrasion Method

Several important facto= must be con-sidered when using abrasion techniques for the removafof coating materials. A powered miniature machiningsystem will permit fingertip control while providinglow RPM at a high torque to facilitate manipulationand the handling of gumming type coatings. In addition,

,a wide variety of rotary abrasive materiafs and shapes,as well as cutting tools, will be required, includingbafl mills, twist drills, rotary brushes, etc., to suitremoval of the various coating types and configura-tions. In principle, the powered mechanical abrasivecoating removal method permits consistent and pre-cise removal of coatings by the average technician with-out causing mechanical damage or dangerous heating.

CAUTION

Do not use high RPM rotarysystems as they will causedangerous frictional heating,and normally do not havesufficient torque to removethe softer, gumming typecoatings.

6-2.4.5.1 Abrasive Removal of Thin CoatingsRubberized abrasives of the proper grade

and grit are ideafly suited to removing thin hard coatingsfrom flat surfaces. They must not be applied for softcoatings removal since these would cause the abrasiveto “load” with coating material and thereby becomeineffective. Rotary bristle brushes are better suitedthan rubberized abrasives for use on contoured orirregular surfaces, such as soldered connections, etc.,since the bristles will conform to surface irregularitieswhile removing hard or soft coatings. When usingminiature machining abrasive techniques, the abrasivetool should be moved about in a circular motion tominimize localized heating and avoid causing damageto underlying materials by abrading through the coating

O.R IGINAL 6-11

too quickly. The procedure for thin coating removafis as follows:

1. Apply appropriate rotating abrasiveto the coating using various degrees of pressure andapplying the degree of pressure which best suits theconditions. It may be necessary to begin with a coarseabrasive to remove the bulk of the coating, then changeto a finer abrasive or bristle brush to “clean up” thearea.

2. When afl coating has been removedfrom the desired area, the area should be cleaned withan appropriate solvent to remove any remaining con-taminants. The cleaned area can now be studied todetermine which solder extraction technique to use.

NOTE

The abrasive method is pr-imarily suited to the circuitside of the boards because itpermits ready access of rotat-ing devices without danger ofdarnage. The thermaf partingand hot jet methods shouldbe used on the componentside of the board.

6-2.4.5.2 Abrasive Removal ofThick CoatingsThe procedure for removing thick

coatings is primarily to reduce their thickness to athin coating, and then to remove the remaining thincoating by the previously described thin coatingremovaf procedure. Use the miniature machining tech-nique with bafl mills to rouhout thick coatings, usingvarious sized mills to enter smafler areas.

CAUTION

Do not attempt to removecdl of the coating or reach

T

the board or part surfacesby this method as the cuttingaction will cause damage.The intent here is merely tothin the coating down.

The design of a bafl mill is such that ita most efficientcutting area is on the side of the ball rather than at theend. To prevent damage to the base material of thePC board, periodically remove the waste coatings


4

by brushing or using low pressure air to aflow visuafinspection of the work surface. Once the coatingaround the selected component has been reducedto a relatively thin condition, use the abrasive or hot jetmode for thin coating removal. Remove the solder jointszs per the appropriate solder extraction method. Thisabrasive method is only suited to thinning down thickcoatings on the circuit and component sides of theboard. Use the thermal parting and hot jet methods torelease the bonds between components and circuitboard.

CAUTION

Do not a t tempt mechan-ical abrasion betweenclosely spaced componentpart bodies as this actioncan easily darnage thepart.

NOTE

Both the thermal parting andhot jet methods are alsoideally suited for the removalof thick coatings.

6-2.4.6 Hot Jet MethodIn principle, the hot jet method uses

a controlled jet of temperature regulated air to eithersoften or break down the coating. By control of thegas temperature, flow rates and jet shape, the hot jetcan be applied without damage to afmost any workpiececonfiguration on both the circuit and component sidesof the board. Due to the application of heat via the hotjet, there is no direct physical contact with the work-piece surfaces. Thus, extremely delicate work can behandled in this manner while permitting direct obser-vation of the heating action.6-2.4.6.1 Hot Jet Procedure

for Coating Removal

1. Set up hot jet apparatus per manu-facturer’s instructions to provide minimum-sized jet.Adjust flow rate and temperature to suit specific coatingremoval application.

2. Apply jet to work area. With the aidof a relatively soft, non-marring edged tool (i. e., teflon,nylon or orange wood), use light prewure to removesoftened or over-cured coating. All coating around indi-vidual leads, solder joints and component bodies canbe removed in this manner.

6-12

CAUTION

Never set the hot jet toheating levels that will causescorching or charring of thecoating material.

3. When coating has been removed,use appropriate solder extraction method to removelead solder.6-2.4.7 Non-Recommended Coating

Removal Methods

CAUTION

Burning the coating off witha soldering iron is not recom-mended since this will causecharring of the coating andheat damage to the base-board. Scraping coatings frommodules by using sharp-edgedmetal blades must not beattempted because of dangerof board damage.

The technician does not usually have sufficient hand-control sensitivity to work to the close tolerances thatare necessary to prevent damage to materials directlyunder the coating. It must be remembered that a thincoating is usually .010 inches or thinner. Hand-scrapingcoatings from circuit areas with hard metallic, sharpedged blades can result in damage to the extremelythin circuit plating and may even cut through thethin, soft copper circuit itself.6-2.4.8 Replacement of

Conformal CoatingTo replace conformal coating on printed

circuit boards the following recommendations shouldbe followed:

CAUTION

Conformal coatings mayaffect the capacitance and the“Q” of inductom in “RF”assemblies. Refer to theappropriate maintenance pro-cedures in the equipmenttechnicaI manual concerningalignment procedures and theproper use of protectivecoatings for “RF” assemblies.

ORIGINAL


L

-.

1. Use a magnified viewer to visuallyinspect the repaired board for foreign matter.

2. Clean area to be coated, using acotton swab that has been dipped in alcohol.

3. Allow the cleaned printed circuitboard to dry thoroughly. Drying time will depend onthe cleansing agent used.

NOTE

When possible, use the samecoating material as originallyemployed. This will assurecompatibility and meet func-tional requirements.

4. All coatings should be applied verythinly, not only for ease of removal, but more impor-tant, to prevent stress cracking in solder jointa. Thespray or brush method should be used to ensure uniformthickness.

5. Before curing the applied coatingby the approved method, inspect the coating with amagnified viewer for voids and pinholes. If any suchare detected, application of another coat will benecessary.

6. After curing, reinspect with the mag-nified viewer for any existing defects. Reinstall repairedPCB in equipment.

6-3 REPAIR OF PRINTEDCIRCUIT BOARDS

Repair procedures for microminiaturePCBS are basically the same as for repair of miniaturePCBS except that the relative size of the componentsand component density will require the use of specialtools and techniques, such as those listed in Table6-1. One type of repair that should be left up to themicroelectronic repair technician is the repair of multi-layer boards.

6-3.1 REPAIR OF MU LTILAYER PCBSMultilayer board repair should always

be performed with the utmost care and using the bestpossible techniques. Only standard repair procedures,good workmanship practices, and fully qualified per-sonnel, who have been trained in advanced solderingtechniques, should be utilized in making repairs.Several very basic rules must be followed. One ofthe most important of these which cannot be over-stressed is, of course, avoidance of excessive heat.

ORIGINAL 6-13

Avoid applying excessive heat and make it a habit toapply the least possible heat to do the job properly.The following defects can arise from excessive heat:

1. Damage to the PTH.2. Board could be scorched.3. Electrical resistance of the epoxy

glass can be lowered, making the epoxy more susceptibleto a voltage breakdown.

4. Epoxy binder material may flow intoa hole and cause contamination.

Another essential point to keep in mind while solderingor resoldering — do not apply heat to the same terminalarea (pad) immediately if not successful on the first try.Allow the connection to return to room temperaturebefore a second application of heat. When replacingmulti-lead components, avoid working on an adjacentterminal area (pad) immediately. Most of the cost ofan expensive assembly may already have been spent,but with care and patience, most of this investmentcan be salvaged. Removal of conformal coating isanother very important point too frequently consideredonly lightly. All conformal coating should be carefullyremoved from both leads and terminal area (pad) priorto the application of heat. Any remaining conformalcoating will deter solder removal and will make theresolder operation very difficult since it will contami-nate the hole being soldered. The few extra minutesspent on removing all conformal coating could verywell prove the best time spent on a particular repair.Urethane resin strapping is normally used to hold largecomponents against the board and thus protect themfrom the effects of vibration. The removal of suchstrapping is accomplished by the careful use of a thermalparting tool for this especially tough materkd and isvery difficult to remove. Refer to paragraph 6-2.4.4for details. In addition to utilizing trained personneland the use of proven techniques, the latest availableequipment sould be employed.6-3.1.1 Repair of Damaged Holes

in Multilayer PCBS

1. Clean surface to be repaired, using astiff bristle brush dampened in perchloroethylene.Rinse with isopropyl alcohol.

2. Special care must be taken to keeprework area localized. Mask and/or plug adjacent holesto prevent the possibility of filling.

3. Select the proper bonding materials(resin and catalyst) and mix as recommended by manu-facturer.


4. Mixinfiberglass #128 and stir untilall fibers are wet.

5. Cure as recommended by manufac-turer, then abrade flush.

6. Small plates coated with releaseagent may be clamped on the filled area to minimizeamount of abrading required to flush.

7. Redrill hole per applicable drawing.

6-3.1.2 Repair of Internal Shorts6-3.1 .2.1 Non Connector Area

1. Make a series of resistance readingsand/or continuity checks. Record the data. Determine,if possible, the exact location of short or shorted holesbefore attempting any drilling.

2. Drill-out barrel of suspected holeor holes, slightly larger than the barrel O.D.

3. Examine hole carefully (using magni-fier viewer) to be sure the entire barrel has been com-pletely removed.

4. Repeat resistance and/or continuitychecks to verify removal of short.

5. Clean hole or holes with isopropylalcohol and mask area around hole.

6. Fill hole with epoxy and cure.7. Abrade flush to surface of board

and clean with alcohol.8. Hard-wire, externally, all circuits

removed by drilling and solder with rosin core solder.Care must be taken in routing external strappings toprevent “Cross Talk. ”

9. Remove all flux residue, usingcotton-tipped applicator and alcohol.

10. Install conformal coat over externalwires.

11. Cement all external wiring to boardsurface (if required) or if board is not conformal coated.

NOTE

Tack external wiring downwith cement in one-inch in-crement, each tack beingapproximately 1/4” in length.

6-3.1 .2.2 Connector Area

NOTE

It is assumed that the boardin question has been testedand a record made of theshorted pins.

6-14

CAUTION

Make certain of the amountof current board will stand.

1. Connect power supply and digitaJvoltmeter leads in parallel with the power supply set at1 Vdc and with the current limited to 5A.

2. Probe shorted pins to ground circuituntil the pin with the greatest voltage drop (leastindicated voltage reading) is located.

3. Using the drill press and trepanningtool, remove all board material from around shorted pin.Good workmanship practice must be used to preventtool from becoming plugged and thereby damagingconnector/pin, After material has been removed, checkas in step 2 to ascertain that short has been removed.

4. Install insulating sleeve over connec-tor pin, not to extend above the bored surface. Fillboard with epoxy and cure.

5. Using acceptable soldering procedureand continuity chart, replace the internal circuit byhard-wiring on the board surface. Epoxy the wire tothe board surface as required. Check electrical circuitfor proper routing and design specifications. Retestboard for shorta. If the short occurs at a hole whereno pin is installed, use drill-bit just large enough toremove the plated barrel from the hole. (It is advisableto check the artwork to see what internal circuitry isbeing removed by drilling, if any.) Fill hole with epoxyand cure. Hard-wire externally all circuits removed bydrilling. Follow same procedure outlined in paragraph6-3.1.2, steps 8 through 11.

6 4 REPLATING

6-4.1 INTRODUCTIONThe technician will need to replate

a printed circuit board whenever it has become impaireddue to physical damage or neglect. Uneven, thin,scratched or blistered gold plating on contact bars maybe replated if the scratches do not reduce the bar cross-section by more than 2W0 or by less than 2W0 of thecontact area. When replating, potentially dangerouschemicals must be used, therefore, only a qualifiedmicro-repair technician should attempt to do the work.The following safety precautions are to be observedin addition to applicable standard safety precautions:

1. Rubber gloves should be worn toavoid possible skin irritation and prevent circuit boardcontamination.

2. Wash gloved hands thoroughly inmild soap and water prior to removing the gloves.

ORIGINAL


k

4. Before putting on rubber gloves,check carefully for holes or other defects that maypermit toxic chemicals to come in contact with the skin.

5. When repairing boards with installedcomponents, be sure that the plating current will not passthrough any of the component. Mask any adjacent cir-cuits or conductors to ensure against inadvertent contact.

6-4.2 SPOT PLATING (TYPICAL)

NOTE

Use manufacturer’s recom-mended solutions and pro-cedures.

STEP I

1. Prepare the stylus in accordancewith the directions. Prior to use, the stylus shall besoaked in the gold solution.

STEP II

1. Use abrader on the area until the sur-face is smooth and atl defective gold plating is removed.

2. Rinse area with deionized water.3. Brush on a solution of Anionic sur-

face active agent for 10-30 seconds to clean the exposedcopper.

4. Rince with deionized water for 30-60seconds. A suitable clean surface can be identified bythe absence of “water breaks. ”

5. Dry the board, using dry gas or air.

STEP III

1. Mask areas only where necessary toprevent component damage.

2. Mount board in a suitable holder.Tilt to prevent the plating solution from running ontothe board.

3. Position return probe to the contactbar at joint near the area to be plated. Take care not todamage bozud or components with sharp point of probe.

4. Plate at approximately five (5)volts for 20-30 seconds at between 40 to 80 Ma. Ifthe area to be plated is large, plate each small area for20-30 seconds. The stylus must be kept moving toprevent “burning” the gold.

5. The stylus shall be dipped into thegold solution before plating each contact bar.

6. Rinse the plated board in deionizedwater.

ORIGINAL 6-15/(6-16

7. Dry board, using dry gas or air.8 . Buff contac t a rea l ight ly unt i l

similar in luster to others.

STEP IV

Perform tape test per IPC Acceptability Guide Lines(A-600-A) as follows:

1. Place a strip of cellophane tape3/8-inch wide (approximately) over contact bars thathave been repaired. Tape shall conform to Type 1,Class A of Federal Specification L-T-90. Use tape thathas been manufactured within the previous 6 months.

2. Apply uniform pressure to the tape.3. Rapidly pull the tape off perpen-

dicular to the board.4. Examine the tape and the board

for evidence of removed plating.5. If there is evidence of removed

plating, repeat the cleaning and plating operations.6. Remove tape residue using iso-

propyl alcohol, or equivalent.

6-4.3 ALTERNATIVE PLATINGREPAIR PROCEDURES

6-4.3.1 Solder on Gold Plating

1. Remove excess solder by vacuumingor by wicking with fluxed end of braided wire. Applyheat only so long as required to melt and remove thesolder.

2. Remove any remaining solder withan electric eraser or similar abrader.

3. Clean with alcohol.4. Replate in accordance - with spot

plating procedure.

6-4.3.2 Thin or Missing Gold Plating

1. Remove all gold using an abrader.2. Clean with isopropyl alcohol.3. Replate in accordance with spot

plating procedure.

6-5 MAINTENANCE OFMI CROSTATION

The microelectronic repair technicianusually has access to some of the most sophisticatedtools an electronic oriented technician could want, con-sequently the proper maintenance of the station willgreatly enhance its capabilities. The micro-electronictechnician should maintain his work station and equip-ment as outlined in Section 5 of this publication.

Blank)

L

L

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 DIGITAL TROUBLESHOOTINGTECHNIQUES

SECTION 7

DIGITAL TROUBLESHOOTING TECHNIQUES

7-1 DIGITAL TESTINGTECHNIQUES

In order to accurately test today’sadvanced digital equipment, the technician must learnhow to use some veW unusual technical troublesho-oting aids. These aids will make the technician’s jobeasier, faster and more accurate. The technician wholearns to use the logic clip, logic probe, logic pulserand current tracer will acquire a good understandingof digital testing techniques.

7-1.1 LOGIC CLIPThe logic clip is designed for logic

level determination only on TTL and DTL logic con-ventions. The clip can test flip-flops, gates, counters,buffers, adders, shift registers, etc. It will not testICS with non-standard input levels or expandable gates.By means of the logic clip the logic levels at all pinsof a dual inline IC will be continuously displayed. Allinput pins are buffered to minimize circuit loading.The clip uses Light-Emitting Diodes (LEDs) to display“high” and “low” levels. The clip automatically locatesthe Iogic chip Vcc and ground pins of the chip, thereby

eliminating any external power supply requirements.To use the logic clip the technician squeems the thickend of the clip to spread the contacts, and then placesthe clip on the IC to be tested. The LEDs on top of theclip will indicate the logic levels at each connected ICpin (the clip may be turned either way). There are nooperating controls on the logic clip.7-1.1.1 Theory of Operation of Logic Clip

The foIlowing refers to the logic clipblock diagram (Figure 7-l). Each pin of the logicclip is internally connected to a decision gate network,a threshold detector, and a driver amplifier connectedto an LED. The decision gate network finds the IC Vcc

pin (power voltage) and connects it to the clip powervoltage bus, activating an LED. The network finds alllogic High pins and activates corresponding LEDs. Allopen circuits are found and corresponding LEDs areactivated. Finally, the clip finds the IC ground pin andconnects it to the clip ground bus, blanking the cor-responding LED. The decision gate network uses thefollowing flow diagram (Figure 7-2). The thresholddetector (refer to Figure 7-1) measures the inputvoltage. If the voltage exceeds the threshold voltage( ~ +2 VDC), the LED is activated. If the voltage isless than the threshold voltage ( ~ +.8 VDC), the LED

ORIGINAL 7-1

is not activated. An amplifier at the output of thethreshold detector drives the LED. If the operationof the logic clip is suspected to be faulty, the operationof each pin network should be tested with relation tothe others. For correct operation the logic clip musthave at least one Vcc pin and a ground pin. Logic clippins not connected to any circuit will indicate a high.A five-volt battery can be used to check each logicclip pin network for correct operation. Connect fivevolts across two pins; the remaining 14 LEDs and the+ Vcc LED should then glow. Ground each pin one ata time (except the Vcc); each LED that has a groundshould not glow. Use an adjustable low voltage powersupply to check the threshold of each log clip pin.

7-1.2 LOGIC PROBEThe standard logic probe will detect

and indicate valid logic levels. It will also indicate thepresence and polarity of single pulses of IO-nanosec-onds or greater in duration. In addition, it will detect“bad” logic levels, such as an open input on a TTLgate, and open circuits, such as an open collector out-put, without pull-up resistors. The input loadingcharacteristics are similar to a low power TTL gateinput: is therefore compatible with almost all TTL andDTL circuitry. The logic level indicator lamp will givethe technician an immediate indication of the logicstates, both static and dynamic, which exist in thecircuit under test. Figure 7-3 shows how the logiclevel indicator lamp responds to voltage levels andpulses. The lamp has three possible states: off, dim andbright. The lamp is normally in its dim state and mustbe driven to one of its other two states by voltagelevels at the probe tip. The lamp is bright for inputlevels above the logic one threshold, and goes off forinputs below the logic zero thershold. The lamp isdim for voltage levels between the logic one and zerothresholds and for open circuits. The indicator willflash on and off at about ten times per second forpulse train inputs larger than 10 Hz. Typical logicprobe specifications are listed in Table 7-1.7-1.2.1 Logic Probe Theory of Operation

The Logic Probe Schematic Diagramshown in Figure 7-4 is used for the following Theoryof Operation explanation. At the probe input, R1 andCR “A” and CR “B” protect the probe from inputoverloads. At the power input connector, CR 1 andCR 3 protect the probe from reversed power con-nections. All input signals are applied to the two

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCETECHNIQUES

~ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -— --- - - -I

I 1

Vcc I iDECISION LOGIC

GATE SIGNAL

NETWORK I vCtdn i Ttii$~i-jOR%y,)1 l-) i“,. W

1 UC I a +udP I,1

1 4 0 J---- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - J

130 —

120 —

110 —

100 —

90 —

Bo—

70 —

60–

50 —

4 0 — l - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ,I

30 +iI

I I, \ ,afi I

ICC3US

2 0 —i ‘bb1

“ LOGICI S I G N A L

10 4’;, GND

THRESHOLD IDET ~ AMP I

I III

I I OF 16 SECTIONSI

L_- -- ------ -- -!

— ---- ---— --- _ --- .------— -------- 1 1

Figure 7-1. Logic Clip Block Diagram

d

,GROUNDBUS

7

parallel detectors. Both detectom compare the inputsigrd to internal reference voltages. If the probe’sinput signal is more positive than the reference voltageof the logic One threshold detector, the detector’soutput will go High. Some hysteresis is injected toprevent instability, should the input voltage be equal tothe reference voltage. The output of gate A is normallyhigh (whereas gate G output is normally low). Theresultant low from gate B sets the SR flip-flop therebyplacing a high on the output of gate C. Coincident withthis event, two things take place: 1) QA lights the logic

7-2

level indicator lamp; and 2) the high outputs from gateC and the One delay causes the output of gate E to golow. This disables gate F and prevents the indicatorlamp from turning off, should the input signal dropto zero during this pulse-stretching time. This cross-coupled disabling characteristic is responsible for thelamp’s 10 Hz flash rate when the input is a high-fre-quency pulse train. Once the high from gate Cpropagates through the One delay ( ~ 50 ins), a lowon the R input of gate D attempts to reset the flip-flop.The flip-flop, however, will reset only if the input

ORIGINAL

.— ------ . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . ---- ,. --- . . . . . . . . . --- . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . . . . . . . . . . . . . . . .TECHNIQUES

CONNECT

:11

HIT IS AUTO- ~N~CONNECTED

LED IS

TO VCC BUSACTIVATED

I I I

IT IS AUTO- LED ISCONNECTED + NOTTO GND BUS ACTIVATED

Figure 7-2. Decision Gate Network Flow Diagram

voltage drops below the logic threshold level. Theindicator lamp turns on to full brilliance when gate Coutput goes high. This occurs when the probe’s inputlevel reaches the “l” threshold. When the probe’svoltage is below the “O” threshold, the SR flip-flopin the zero channel is set high and thus prevents gateJ from lighting the indicator lamp. The high from theflip-flop and the high from the Zero delay preventthe One flip-flop from setting. When the probe voltageis not positive enough to activate the One channel orlow enough to activate the Zero channel, both flip-flopsare low. Both low outputs become connected to gate J,which turns QB and the lamp ON. Diode CR “C”provides an added diode voltage drop in the emitter

ORIGINAL 7-3

circuit and causes the lamp to glow at only half itsbrightness. If the probe input is continuously Highthe One channel flip-flop output and the logic lampwill be High (the lamp will be ON) continuously.A single fast positive pulse, 5-10 nanoseconds orslower, will actuate the ONE channel flip-flop toproduce a 50-millisecond bright logic lamp flash.The delay circuit stretches the pulse. A positivepulsating signal with a frequency even slightly greaterthan 59 MHz will cause the lamp to flash on forabout 50 milliseconds at a rate of 10 times per second.The delay circuit stretches the pulses. Negative levelsor pulses will cause the lamp to switch off for about50 milliseconds.


INPUTSIGNAL

LOJ;C

[ J2 . 2 - - - - - - - - - - - - - -THR&H&LD 2 . 0 — ‘ - - ‘- - – -- - – --

+.8 – - - - - — - –- - – - -

BAD LEVELOR OPEN CRT ‘“ - ‘ -- -- - I

I I 1I I I

I I

BRIGHT - – -- - - - –[– --- –

+II I

.05SEC -D

I

.

10 NANOSECONDSINGLE PULSE

Figure 7-3. Logic Level Lamp Indication with Probe Input Voltage Levels

.

ULSES UP TO0 MHi CAUSEIGHTT 10-

0 BLINK{z

1

7-1.2.2 Operational ChecksNo adjustments or preventive main-

tenance procedures are required for the logic probe.IIowever, operational checks can be made to ensurethe probe is operating correctly. With the logic leveltest setup shown in Figure 7-5, the technician shouldset power supply B to +5 V ? 1~0 and power supplyA to give a probe voltage of +1.5V. The probe lampshould now glow dimly. Adjust power supply A untillamp glows at full brilliance/prohe tip voltage shouldnow be 2.0 V ~.2V. Adjust power supply A downwarduntil lamp glow is extinguished; probe tip voltageshould now be .8V ?.2 - .4V. If the probe powersupply is not +5 V, the 1ogic thresholds will change.The change is approximately .3 volt-threshold increaseper volt of power supply increase. When using the posi-tive pulse test setup (Figure 7-6), set power supply Bto +5V. Set pulse generator to give a positive-going10 nanosecond pulse. Set the repetition rate to aboutone pulse per second. The probe lamp should flashat a once-per-second rate. With the negative pulse testset (Figure 7-7), set power supply B to +5V and power

7-4

supply A to 10V. Set pulse generator output polarityto negative. Adjust the pulse geneator to give waveformat the probe tip as shown in Figure 7-7. With a repeti-tion rate of one pulse per second, the probe lampshould flash off once per second. Table 7-2 shows therecommended test equipment for performing thesetests.7-1.2.3 Troubleshooting with

a Logic ProbeWhen using the logic probe, a DC supply

can be obtained from either the circuit under test orfrom a separate +5 VDC supply. If a seperate supplyis used, the circuit under test and the power supplygrounds must be connected together. A ground clipis provided to improve pulse width sensitivity and noiseimmunity. The ground clip’s use is optional. The logicprobe is ideal for detecting short duration pulses andlow repetition rate pulses that would otherwise be verydifficult to observe on an oscilloscope. Positive pulsesto 10 nanoseconds or greater in width trigger the lampon for 50 milliseconds or longer. Negative pulses causethe lamp to momentarily go off. Several logic circuit

ORIGINAL


Table 7-1. Typical Proke Specifications

Positive Logic Threshold VoltagesLogic “l”: 2.0 f .2 voltsLogic “O”: .8 ~ .2 -.4 volts

[nput ImpedanceGreater than 25,000 ohms

Pulse Width Sensitivity10 Nanoseconds

MAX PRFGreater than 50 MHz

Input Overload Protection? 70 VDC Continuoust 200 VDC Transient

120 VAC for 30 seconds

Power Requirements+ 5VDC @ 60 milliamps-15 VDC

Operating Environmento ‘c - 55“c

analysis techniques lend themselves for use with logicprobes. One technique is to run the circuit under testat its normal clock rate while monitoring for variouscircuit control signals, such as reset, start, stop, shift,transfer, or clock signals. Questions such as “Is thecounter working?” are easily resolved by noting ifthe probe indicator is flashing on and off, whichindicates that pulse train activity is present. Anotheruseful technique is to replace the normal clock signalwith a very slow clock signal for a pulse generator, orto single-step the clock input with a logic pulser (thepulser will be discussed later). The changes in logicsignals should now occur at a rate slow enough thatthey can be observed on a real time basis. This realtime analysis technique, coupled with the ability toinject logic level pulses anywhere in the circuit with thelogic pulser and the ability to detect logic state changeswith the logic probe, contribute to rapid trouble-shooting and accurate fault tracing in digital circuits.7-1.2.4 Logic Test Probe

All modern electronic equipmentinvolves the use of some digitrd circuits to performvarious functions. It is therefore necessary to devise amethod of easy troubleshooting for locating faultyintegrated circuits or logic output cards. A simple

ORIGINAL 7-5

and quite reliable method employs the logic testprobe. Since the output of a digital circuit employseither a 1 or O (zero) condition, the logic test probecan, at a glance, indicate the circuit’s present state.The input(s) can then be verified by the same method,and a study of the circuit under test can determineif the correct output is present. (Refer to the digitaltroubleshooting methods section of this publicationfor a more detailed procedure for determining theproper output state of a logic circuit. Various logictest probes are available through the Naval SupplySystem and in the commercial market. Considerationsmust be observed when selecting a probe for a specificintended use. These considerations are:

1. Frequency Response2. Minimum Pulse Width Response3. Circuit Loading4. Power Versatility

7-1.2.4.1 Frequency ResponseThe frequency response of the probe

must be greater than that of the circuit under test.This allows the logic probe time to correctly identifythe circuit’s output condition and then reset for thenext output indication while continuously monitor-ing a particular logic train. The probe divides this logictrain down to a rate in which the LED can be notice-ably gated on and off, and not appear to be constantly“on” for a high frequency series of one-state-logicpulses. Probe response frequencies will range from2 MHz to 100 MHz, depending on the one selected.Typical high quality probes are of the 50 MHz variety,with 10 MHz being quite acceptable.7-1.2.4.2 Minimum Pulse Width

CharacteristicsPuke width characteristics are a prime

consideration when dealing with high-speed logiccircuits. Many logic probes employ protection circuitsto prevent them from being falsely triggered by noiseor by power source variations. Selecting a probe thatwill identify pulse durations in the nanosecond rangeis mandatory for testing modern logic equipment.Typical quality probes range from 10 to 100 nano-seconds.7-1.2.4.3 Circuit Loading

As with any electronic test equipment,the amount of additional load that the test equipmentprovides to the driving circuit must be considered inorder to avoid possible fake indications. The additionalload of a logic probe on an integrated circuit may, insome cases, prevent a logic circuit from changing its

GENERAL MAINTENANcE NAVSEA SEOOO-00-EIM-160 DIGITAL TROUBLESHOOTINGTECHNIQUES

I

1-—

4

y“t-

7 - 6 ORIGINAL


L

+;K3V-i-&’i‘

+5VA DCVM

P..s

//

/‘PROBE~

1000c-1 , “ 1

7’------- -v ------- --v

-- ‘K~6 ii6iD LEADS SHORT

Figure 7-5. Logic Level Test Setup

SCOPE

c +5VP. s.

( B/

PULSEGEN - - - - - - - - - - -- - -

- - - - - - - ‘- -- ‘iiE;-iROUND LEADS SHORT

:fid-%IPPS

Figure 7-6. Positive Pulse Test Setup

L

state. A “grey area” exists in logic equipment whichallows for additional errors. This is known as the“Indeterminate Region.” In the “IndeterminateRegion,” the exact response of a logic circuit cannotbe predicted. Safeguards have been included in circuitdesigns to ensure correct input and output levels ofintegrated circuits and that these levels will always lieOutside the “grey region” for either state. Figure 7-8shows that during time frame “A” a constant “l” stateof logic exists. A logic test probe would show a l-statelamp illumination. Time frame “B” shows a O (zero)logic state, and the logic test probe would show the

ORIGINAL 7-7

“l-state” lamp being extinguished and, if provided,an “O-state” lamp illuminated. Time frame “C” in thefigure indicates two pulses of tbe l-logic state. Thelogic prohe lamp would now flash twice. If an “O-state”lamp is provided, it would not be illuminated becausethe negative excursions of the pulses did not cross theO-state threshold. Time frame “D” indicates two pulsesof O-state logic, therefore the O-state lamp would lightup for two flashes. However, the l-state lamp wouldnot have illuminated because the positive excursionsdid not cross the l-logic threshold. Time frame “E”indicates an alternating “O” and “l” state. The leading

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-00-EIM-160TECHNIQUES

F+ IovP.s.A

4

Iouf

GENERAL MAINTENANCE

5/+5VPSI.B

PULSEGEN

-‘- il~[; 6iouND LEADs S H O R T1 1

I I

I SCOPE I

Figure 7-7. Negative Pulse Test Setup

Table 7-2. Recommended Test Equipment

1.2.3.4.5.

6.7.8.9.

0-20 V O-1A power supply0-10 V O-1A power suppIyDC VOM ammeter 1% accuracyPulse generator 0-1 ms pulse widthOscilloscope

.3 Hz -10 MHz repartition rate250 MHz bandwidth10 mv/div sensitivity, vertical1 ns/div sweep, time base500 MHz active probe

2- 100!2resistors1 -.1 pF capacitor2-10 #F capacito~1-1 k~resistor

and trailing edges of the pulses are seen as clearlycrossing the thresholds of both the O and the 1 states.This would cause an alternating flash between theO and 1 lamps on the logic test probe. The logicihreshold exists at roughly J 1.3 volts and ~ 1.9volts. Many logic probes have a wider threshold area(~ .7 volts and <2.15 volts). Within these areas theproper operation of the circuit under test and/orthe logic test probe will be questionable. This problemis common when using a probe not properly designedfor CMOS integrated circuits. The application of thelogic probe tip to a circuit test point loads the circuitto a point where the signal present falls within thegrey area. This causes the circuit to malfunction

d

7-8

by imposing an excessive load on the driving circuit,leading to possible failure of that particular drivingcircuit. A malfunction may afso be due to simplyloading the signal to within the grey area, causing thefollowing circuit not to respond. Impedance of logictest probes range from 5K ~ to over one half megohm.7-1.2.4.4 Power Versatility

Most logic test probes operate from apositive or negative five volt power source with a tenpercent tolerance. Logic probes can have accessorieswhich allow the probe to operate from sources toi 30 volts and protect the probe from damage fromvoltage sources. Input signal levels to the probe tipare normally on the order of f 5 volts, although somelogic circuits use a high-level logic of f 15 volts.Input signal levels from a failed chip may reach theapplied source voltage of that chip. A logic probe maytherefore be damaged if the probe design does notallow for overvoltage protection at the probe tip.This protection is usually achieved by inserting asubminiature fuse in the tip circuit.7-1.2.4.5 Construction of a

Simple Logic ProbeA simple functioned logic probe can

be fabricated using materials commonly stockedthroughout the fleet. Three such probes will be shown,and all are acceptable for TTL, DTL and RTL circuits.Good workmanship is as essential in probe fabricationas in afl projects requiring precision. Figure 7-9 showsa probe constructed from common parts normal]yavailable and is the simplest of designs. This probe

ORIGINAL


,

. ILO(3C ITFH3ESHOLD

L

IINfXITERMINATEGREY REGION

L= 0THRESHOLD

—

— 1 — — t — — + – +OVOLT—

L

Figure 7-8. Logic Threshold and Pulse Conditions

+ SW

10-20 4K * \ I

[

INPUT

I01 + 270

+al

2N42SS L4.7K

MLED 50 J - 1 ’

m

PARTS L 1ST

QI - 2N4265 OR EQUIV.

UI - 7400 quad NAND

cl - .01 Uuf

MINATURE LED - MLED50

.- LEO SPDTn

&---

ll@E?han

-m”./L- SCREW ON TIP&R#lWURE L “~RT OF OLO

9COPE PNOIME 9ALLIGATORCLIPS

---- - .._——

Figure 7-9. Construction of a Simple Logic Probe

has a memory for detecting a pulse that occurs onlyoccasionally over a period of time, and a single flashof the LED might be missed by the observing techni-cian. If such a pulse occurs, the LED will light andstay lit until the memory disable switch has beencycled. Another feature of this design is the presenceof a polarity switch for working with either negativeor positive logic. The limitation of this probe is thatit is primarily designed for troubleshooting circuits

ORIGINAL 7-9

whose states are not constantly changing. A singlepulse will cause the LED to light and stay lit whileholding the memory disable switch in its “on”position. A train of pulses will cause the LED to light,but only at half brilliance. The second of three probes(Figure 7-10), features a very versatile design which isthe superior of the three designs presented here.Construction time by a technician is approximatelythree hours. This logic test probe will detect pulse

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-00-EIM-I 60 GENERAL MAINTENANCETECHNIQUES

=

R5+

LI , 6

R6 //‘ 2 9 IC2

R7 ‘z L3 , 0

12

A3 4 1 2 9 5 1 4Icl I

d10 II 7

+ =

1

K,: SI

4 7

5

cl

3RY

PARTS LISTDI-D2 IN914QI 2N404Q2 2N706Icl 741211C2 7475RI, R2 IOKflR3,R4 I KnR5-R7 150nCl 50uf(ldv.) IOVDCSI SPSTLl LED(PULSE)L2 LED( LWtf)L3 LED(HIGH)ALL RESISTORS ARE 1/4 WATT 50/0

Logic Probe Circuit
Figure 7-1o.
widths of 50 nanoseconds and has a frequencyresponse in excess of 10 MHz. In operation, LED L1flashes to show that the input is changing and is of asufficient level to cause the test probe to show either a1 or a O (zero) state. This is known as a pulse“Stretcher/Detector” operation. The LED L2 lightafor a logic O state, whereas LED L3 lights for a logic 1state. The probe can be mounted in a coin collectortube or in a suitable plastic pill container obtainedfrom the medical supply system. A toothbrush case ofsoft plastic is best for rough conditions where probebreakage may otherwise occur. The IC chips aremounted back-to-back for compactness. The probetip is the shaft of a miniature screwdriver cut tolength. Insulate aU but the shaft tip with heat shrinkable

7-1o

tubing. A miniature SPST toggle switch, such asfound in many AIMS/IFF equipment, can serve asthe memory switch. Eighteen-inch-long leads ofstranded wire with covered alligator clips were usedfor connecting the probe to a power source. The thirdlogic probe design (Figure 7-11) provides for a readoutof logic state, and is also a pulse stretcher/detectorthat cycles itself off after 300 milliseconds. The caseinto which it is mounted is a 5/8 inch O.D. x 3-3/4-inch plastic tube.

7-1.3 LOGIC PULSERA “logic pulser” stimulates TTL and

D1’L logic circuitry. Table 7-3 lists typical logic pulserspecifications. The pulser requires +5 VDC to operate.

ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 DIGITAL TROUBLESHOOTING

PROBETIP

TECHNIQUES

8 DSIi MODIFIED

+5V?

+ 5V

?

1470rl

PARTS LIST

Q1- 2N3904 OR EQUIV.D1-1 N914D2-IN914DSI-PINLITE DIP-630 OR650UI -7402U2-74121RESISTORS AS MARKED ARE1/4 WATT

II Y+5V

PULSE STRETCHER

4,7uf TANTALUM

/PULSE

INDICATOR

loon MV-50

Figure 7-11. Modified Logic Probe

The input power should normally be taken from thecircuit under test. If it is not possible to thus use thetest circuit, then a separate +5 VDC supply may beused for power. However, in the latter case, the powersupply common return must be connected to theinstrument under test. The purpose of the logic pulseris to generate one Low and one High pulse each timethe associated probe is triggered. Triggering is ac-complished by depressing a micro-switch located onthe probe body. The state of the test node is of noconcern to the technician due to the fact that the logicunder test will be driven either from a high to a low,or from a low to a high. The high source and sinkcurrent capability of the pulser can override IC circuitoutput points, onginafly in either High or Low states.l%e output pulse width of 0.3 I-& limits the amount ofenergy delivered to the device under test, therebyeliminating the possibility of destruction. The pulserhas a tri-state output. In its “OFF” state the probe’shigh output impedance ensures that circuit operation isunaffected by probing until the pulse switch is pressed.

ORIGINAL 7-11

Pulses can be injected while the circuit is operating andno disconnections are needed.7-1.3.1 Theory of Operation

of Logic PulserWhen the pulser switch is activated

(refer to Figures 7-12 and 7-13), the timing sequencestarts by resetting the R-S flip-flop. The F-F “out”terminal (pin 8) goes Low from High (when the pulseswitch is released, the flip-flop sets, and pin 8 goesHigh). Before the pulse button is pressed, UIB (Pin 3)is normally at 2.9 volts (a logic High). The Low pulsefrom UIB (pin 9) is differentiated by C3, R2, andR g. The output of UIB (pin 2 goes High when theinput goes Low. When the input voltage at UIB (pin3) uses the switching threshold, the output of UIBswitches back to Low. The UIB positive output pulsetime is approximately 0.3 microseconds. This time iscontrolled by C3, R2, R9 and the switching thresholdof UIB. The positive pulse from UIB (pin 2) is appliedto both the High pulse output channel and the Lowpulse output channel. The positive pulse at the input

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCE

Table 7-3. Typical Logic Pulser Specifications

Sensitivity:

Frequency response:

Rise time:

Power Supply Requirements:

voltage:input current:

max ripple:overvoltage protection:

1 ma to 1 A

light indicates single step currenttransitions; single pulses >50 msin width; pulse trains to 10 MHZ

~ 200 ns @ 1 ma

4.5 to 18 VDC< 75 ma~ 500 mv above 5 VOC~ 25 VDC for one minute

UI PINNUMBER

8

3

2

12

14

9

10

BUTTON BUTTONPRESSED RELEASE

H - - 4 4L /(11 )J

iH -L

-.3 MICROSOUND.—I

P ‘- -NEGATIVE PULSE CHANNELI

H - -L

Hi

L - -

I

H:-—

L — POSITIVE PULSE CHANNEL

Figure 7-12. Logic Pulser Timing Diagram

of the logic low pulse output channel (UIF) is invertedat the output (pin 12). The pulse is amplified and in-verted to a positive pulse by Q2. This pulse is appliedto the base of Q4 and drives the transistor into satura-tion. The collector is clamped to the common returnfor the duration of the pulse. The logic High pulseoutput channel (UIA) inverts positive pulse fromU1 pin 2. The negative puke at U1 (pin 14) is dif-ferentiated by C2 and R 1. The positive going dif-ferentiated puke at pin 9 (Figure 7-13) is inverted byby UIE and a delayed, negative pulse is produced atthe output of UIE (pin 10). This pulse starts thenthe original UI (pin 2) pulse stops. The negative pulse

7-12

from UI (pin 10) switches Q1 on for the pulse time,producing a positive pulse at the collector. The positivepulse from the collector of Q1 switches Q3 on thusproducing the positive output pulse. Capacitor C5supplies current for the High pukes. Capacitor C6provides a low impedance path for the output pulseand protects the pulser from any DC voltages thatmay be inadvertantly applied to the pulsers’ outputprobe tip. Resistance R8 supplies a discharge pathfor C6. The prohe is protected by CR1, DS1, and Clfrom overvoltage being applied to the power supplyleads. Reverse polarity protection is provided by CR1,and DS1. Capacitor Cl filters power suppIy spikes and

ORIGINAL


r–- -----1

II

;

II

II

I

I

-- — ——- ---

III

II

II

I

L

ORIGINAL

0

7-13

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-00-EIM-160 GENERAL MAINTENANCETECHNIQUES

LOGIC n PROBE BLINK OFFPROBE GATE OK

HTEST

L GATE

n- l - rLOGICPULSER

Figure 7-14. Logic Gate Testing

LOGICPROBE nv

LOGICPULSER Q

l-i

L

PULSER IS ACTIVATED, PROBELIGHT DOES NOT CHANGESTATE : LINE IS SHORTEDTO VCC OR GROUND.

Figure 7-15. Testing for Shorts

R 7 protects the output channels from damage due toovervoltage or from reversed power supply connections.7-1.3.2 Troubleshooting with

a Logic PulserThe technician can use the logic pulser,

logic probe and logic clip jointly to throughly testa logic gate. For example, a logic gate may h testedby pulsing the gate’s input while monitoring the outputwith the logic probe (refer to Figure 7-14). The logicpulser generates a pulse opposite to the state of theinput line and thus can change the output’s state. Thisensures that the output of the gate is not clamped inits state by another input; for example, a High on theother input of an OR gate. If the pulse is not detectedat the output, pulse the output line (refer to Figure7-15). If the output is not shorted to Vcc or the com-mon return, the logic probe should now indicate apulse. If not, check for external shorts before removingthe IC. The logic pulser may also be used inconjunction with a logic probe to verify the operationof inverter-amplifiers. By pulsing the input to the inver-ter-amplifier (refer to Figure 7-16) and placing thelogic probe on the output the technician shouldobserve a pulse on the output line. If no puke isdetected the output line should be checked for shortsas described above (refer to Figure 7-15) prior toreplacing integrated circuits. When testing counters,flip-flops and shift registers, the following proceduresmay be used. These devices typically have several out-put pins where data must be monitored when testing.The logic pulser, when used as a manually-controlledclock, allows the logic clip to simultaneously examineall output data at rates convenient for viewing. Whenthe logic clip is placed on an IC, the LEDs on the clipindicate the logic state of each pin. As the puker clocksthe input, the indications on the clip can be comparedto a “truth” table.

7-1.4 CURRENT TRACEROne of the more recent state of the arts

took designed for use by digital technician is called a“Current Tracer.” The device is a hand-held probewhich enables the precise localization of low-impedancefaults in digital systems. Basically, the probe sensesthe magnetic field generated by a pulsating currentinternal to the circuit or by current pulses supplied byan external stimulus, such as a logic pulser. The techni-cian will receive a visual indication of the presence ofcurrent pulses by the excitation of an indicator lamplocated near the probe’s tip. Adjustments of the

7-14

probe’s sensitivity over its working range (1 milliampto 1 amp) is accomplished by a sensitivity controllocated near the indicator.7-1.4.1 Theory of Operation of

Current TracerFor the theory of tracer operation, refer

to the probe schematic, Figure 7-17. The currentstep sensor comprises a pickup core and winding and

ORIGINAL


LLOGICPROSE

NO STATE CHANGEINVEKTER FAULTY

H

L

n l - r

GATE

LOGICU PULSER

Figure 7-16. Verifying Operation of Inverter-Amplifiers

an eddy-current shield. The signal to be traced is sensedby the pickup winding and core. The variable-gainpreamp consists of Q1 and peripheral components. Thesignal from the current-step sensor is fed directly to thebase of Q1 and the output of Q1 is taken direct toU1. The gain of the variable-gain preamp is controlledby an ac-coupling of the emitter and collector of Q1(via capacitors C4 and C5) to the current-controlledvariable resistance presented by diode pairs CR4-CR6and CR5-CR7. Each end of each diode pair is returnedto signal ground or one of the ac-grounds formed bycapacitors C6, C7, and C8. Diodes CR1, CR2 and CR3determine the value of control current for the diodepairs. The gain control network adjusta the gain ofthe variable-gain preamp from -40 dB to +20 dB withan essentially constant high bandwidth. U1 serves toincrease the output of the variable-gain preamp. Inter-state ac-coupling of U1 is effected via R12 and C1O.The output of the fixed gain amplifier is ac-coupIedthrough C12 to amplifier U2, which provides addi-tional gain. The output of amplifier is internallycoupled to a bipolar peak detector (paM of U2) wherea pulse of either polarity results in rapid charging ofcapacitor C14. This charging signal, a positive stretchedvers ion of the input, with an amplitudeproportional to the input, discharges through R20. Theoutput of the bipolar peak-detector is fed into anotherpeak-detector consisting of an operational amplifier(P/O U3), with an additional stage in the feedbackloop (P/O U2). When the signal imposed on C14 ispositive, C15 becomes rapidly charged by U2 untilthe inputs to the operational-amplifier becomeequalized. The charge on C15 then slowly dischargesthrough R18, stretching the input pulse for sufficienttime to light the indicator lamp DS1. (Refer to Figure7-17.) The signal at C15 is de-coupled to the dcamplifier, which consists of an operational-amplifier

n= I@ I ml A I 7-1 K

(P/O U3) and series-pass transistor Q3. The gain isset by R25 and R27; C19 is provided to suppress oscil-lations.7-1.4.2 Troubleshooting with

a Current TracerTbe current tracer operates on the prin-

ciple that whatever is driving a low impedance faultmode must also be delivering the most of the current.Tracing the path of this current thus leads directly tothe fault. Problems that are compatible with this

diagnostic method are:1. Shorted inputs of ICS.2. Solder - bridges on PCs.3. Shorted conductors in cables.4. Shorts in voltage distribution net-

works. (Vcc - to grid - shorts)5. Stuck logic data bus.6. Stuck wire - AND structure.

The desirability of current tracer use is usuallyindicated when conventional troubleshooting revealsa low-impedance fault. The technician then aligns themark on the probe tip along the length of the printedcircuit trace at the driving end and adjusts the sen-sitivity control until the indicator load barely lights.The probe is then moved slowly along the trace orplaced directly on the terminal points of the nodes (orIC pins), while observing for brightness of the indicatorlight. This method of following the path of the currentleads directly to the fault responsible for the abnormalcurrent flow. If the driving point does not providepulse stimulation, then the node may be drivenexternally by using a logic pulaer at the driving point.One of the most difficult problems encountered introubleshooting ICS is imposed by a stuck wire - ANDnode. Typically one of the open-collector gates maycontinue sinking current even after it has been turnedoff. Refernng to Figure 7-18, the technician shouldplace the current tracer on the gate side of the pull-upresistor. He must then align the mark on the probe tipalong the length of the printed-circuit trace, and adjustthe prohe’s sensitivity control until the indicator isjust fully lighted. If the indicator will not light, thenhe must use a logic pulser to excite the line. When thetracer tip is placed on the output pin of each gate onlythe faulty gate will cause the indicator bulb to light.When a low-impedance fault exists between two gates,the current tracer and logic pulser, when used in com-bination quickly pinpoint the defect. In Figure 7-19,gate A output is shown shorted to ground. Place thepulser midway between the two gates and place thecurrent tracer tip on the pulser pin. Pulse the lineand adjust the current tracer sensitivity control untilthe indicator bulb just lights. First place the currenttracer tip next to gate A and then to gate B, while

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-00-EIM-160 GENERAL MAINTENANcETECHNIQUES

q-+

I

I

#I

-D

I

E.“

k

d

7-16 ORIGINAL

GENERAL MAINTENANCE

FAULTY GATE~J1 - - - - - - ~H

NAVSEA SEOOO-OO-EIM-160 DIGITAL TROUBLESHOOTINGTECHNIQUES

—

TRACER WILL LIGHT

Figure 7-18. Wire AND-node Fault

-1MOST OF THE PULSE *CURRENT FLOWS INTOFAULTY GATE A

Figure 7-19. Gate-to

L

ADJUST TRACER HERE

~— - - — - - - fH

H

LFigure 7-20. Solder Bridge

ORIGINAL 7-17

continuing to excite the trace. The tracer will lightonly on the gate A side, since gate A (the defect)is sinking most of the current. When checking printedcircuit traces which may be shorted by solder-bridgesor by other means, start the current tracer at the driverand follow the trace. Figure 7-20 shows an exampleof an incorrect current path due to a solder bridge.As the tracer probe follows the trace from gate A to-ward gate B, the indicator bulb remains lighted untilthe tracer passes the bridge. This is an indication thatthe current has found some path other than the trace.Visuafly inspect this area for solder splashes, etc. Thesetechniques also apply when troubleshooting shortedcable assemblies. Another type of IC model structureis the one-output, multiple-input configuration. Figure7-21 shows this type of circuit being pulsed by a signalon gate A’s input. In this case, p[ace the currenttracer’s tip on the output pin of gate A then adjust thesensitivity control until the indicator light just comeson. Then check the input pins of gates B through E.If one of the input pins is shorted, that pin will be the

-Gate Fault

in Printed Circuit


E=EDH

Figure 7-21. Multiple Gate Inputs

only one to light the indicator. Should the indicatorfail to light when placed next to gate A’s output, it isa valid indication that gate A constitutes the problem.Troubleshooting CMOS and ECL circuits is performedin the same manner as for TTL circuits; the only dif-ference being in the voltages availabe for the currenttracer’s power supply connections. Table 7-4 shows thevoltage range from each.

Table 7-4. Typical Voltage Ranges forCMOS, ECL, TTL Logic

CIRCUIT

CMOS

ECL

TTL

TYPICAL RANGE

3 VDC to 15 VDC

-5.2 VDC to O VDC

O VDC to 5 VDC

7-1.5 LOGIC COMPARATORAnother device that merits considera-

tion is known as a “logic comparator.” The comparatoris an IC troubleshooting tool that electrically comparesa reference IC to an IC under test. The reference ICshares the power and input signals with the test IC.When comparing the output of the two ICS, any leveldifference existing for 0.2 pa or more will light anLED on the comparator, thereby indicating a faultexists. The logic pulser allows incircuit stimulation, sothat test pulses may be introduced at circuit nodes.Thus, reset or synchronizing pulses may be injected toreset the comparator IC to the same initial state asthat of the test IC. This allows both the referenceand test ICS to start at the same initial reference point.

7-1.6 LOGIC ANALYZERSMinicomputer system users can txmefit

from a better knowledge of debugging and trouble-

7-18

shooting procedures which use logic analyzers. Thebest way to obtain an overview of what a logic analyzeris and how it is used with minicomputers is to examinesome of the common uses. The following techniquesare also applicable to microprocessors and largercomputers.7-1.6.1 Software Diagnostic Techniques

Problem solving in a minicomputer isusually a complex task. A typical system can consistof a computer and many peripheral units. One ormore of these peripheral units can also be considered“intelligent” with respect to the minicomputer. Asvarious systems have been developed, sets of trouble-shooting programs have been developed which arecalled “program (software) diagnostics.” Softwarediagnostics are used to troubleshoot the CentralProcessing Unit (CPU) and units on memory and input/output (1/0) buses. A well-designed software diagnosticcan usually identify a specific faulty module, but can-not always identify the cause of malfunction. Softwarediagnostics have several major limitations when solelyused for troubleshooting, namely:

1. To use the diagnostic effectively,the system must be running at a minimal level.

2. A dead system or hung-up bus can-not be troubleshot with software.

3. Intermittent problems are difficultto find using diagnostics.

4 . Diagnos t ics wi l l normal ly notidentify software problems.For a full set of troubleshooting tools, softwarediagnostics must be joined with instruments whichmonitor system lines, activity, and timing in terms ofreal time. For troubleshooting minicomputer systemseffectively the real-time analytical capabilities of alogic analyzer are needed.7-1.6.2 Limitations

Microprocessor-controlled logic analy-zers provide a powerful measurement tool capableof testing complex minicomputer systems. To be usefulin troubleshooting, the logic analyzer must be able tocollect, store and display information, perform func-tional measurements, and interface with other mea-surement devices.7-1.6.3 Data Acquisition

Logic analyzers monitor minicomputersystems when running at their normal speeds. Twoquestions arise because of this: 1) how is the dataacquired; and 2) what does this data represent?7-1.6,3.1 Data Channels

A typicaf minicomputer has 16 or18 bits of address; some may have as many as 32.This article primarily addresses a 16-bit unit for data,plus two control lines (18 total). Consequently, even

ORIGINAL

GENERAL MAINTENANCE NAVSEA SEOOO-00-EIM-160 DIGITAL TROUBLESHOOTINGTECHNIQUES

early models of logic analyzers accommodate aminimum of 16 input channels plus two or more inputsfor control lines or external signals. Units having32 inputs can employ four or more auxiliary inputchannels.7-1.6.3.2 Trace Specification

The data collected by a logic analyzerand shown on the display is called a “trace, ” just likethat on an oscilloscope. This trace provides a “window”on the data flow state of the minicomputer. The pro-cess of determining where to place the window is called“trace specification.” The simplest trace specificationis a single pattern trigger. For simple in-line programflow, a particular state is set on the analyzer. Whenthat state appears for the first time, it acts as a triggerfor the logic analyzer memory, and the subsequentstates are stored. Programs in minicomputer systems,however, are rarely simple, therefore a more sophisti-cated trace specification is needed. Consider now aprogram with many complex branching networks(Figure 7-22). A sequential trigger, such as shown inFigure 7-22 permits a trace to be obtained for a uniqueprogram path selected from several different paths.Sequential triggering can also be used to pick upparameters entered early in program flow for use insubsequent subroutines. The logic anafyzer then dis-plays these parameters first, just ahead of the tracelisting of the subroutine.7-1.6.4 Multiple-Occurence Trigger

A multiple-occurent trigger provides avaluable trace specification for unraveling nestedloops in program flow. For example, a program maysample many peripheral units sequentially (majorloop), receive data from each peripheral unit (minorloop), and then format data from each transmission(subminor loop). The combination of a sequentialtrigger and a multiple occurrence trigger could focusthe analyzer window such that it views only thesixth data format of the third data transmission fromperipheral unit three. Two trace specifications whichhelp to monitor the clock and contxol lines are: theORed trigger and the ANDed trigger. one anafyzer (HPModel 1615A) has a glitch trigger which initiates atrace if interference of a specified magnitude occurson a designated signal line. These trace specificationsprovide quicker and more effective analysis of mini-computer systems. They allow the technician to checkonly state flow that is pertinent to the problem, andfocus more quickfy on hardware of software that maybe malfunctioning.7-1.6.5 Data Storage

Trace specification is a selective trace,hence only the states of interest are stored in the logic

ORIGINAL 7-19

analyzer. Data thus stored for analysis can be restrictedto a particular operation, specific activities, or to a cer-tain range of addresses. To capture every state activitywould require excessive memory capacity, and wouldtax the technician’s time by forcing him to studylarge amounts of output data in order to locate singlemalfunctions. A selective trace provides the dataneeded, and omits activities that are of no importanceto the situation under investigation.7-1.6.6 Data Display

After the desired data has been stored,it must be displayed in a meaningful format foranalysis. Logic analyzers offer a variety of formats,which fall into three general categories: 1) list displays,2) timing diagrams, and 3) overall system overviews.7-1.6.6.1 List Display

The most frequently used format is alist display (Table 7-5) which is a convenient formatfor detailed analysis of software execution. Freedomto specify the format will vary with the particularlogic analyzer used. The two logic analyzers used forexamples here will be the HP 161OA and the HP 1615 A.The technician can choose clock slopes, logic polarity,numerical bases, and group inputs under differentlabels.7-1.6.6.2 Timing Diagrams

The model HP 1615A Logic Analyzerprovides an 8-channel timing diagram (Figure 7-23).Figure 7-23 timing display shows activity on controllines for a typical bus data transaction as a displaymode. Timing diagrams show the actuaf time relationbetween control lines; these diagrams facilitate investi-gation of “handshake” and control state problems. TheHP 1615A can display timing phenomena that occurprior to a trigger point, make single-shot multichannelmeasurements, and detect and trigger or glitches.7-1.6.6.3 System Overview

The graph mode (Figure 7-24) providesa convenient display feat~!re which is available on theHP 1610 Logic Analyzer. A selected parameter, i.e.,address, is plotted with magnitude on the Y-axis, andthe sequence of its occurrence is plotted on the X-axis(Figure 7-24). With this form of display, the techniciancan quickly identify irregularities and breaks inprogram flow. Figure 7-24 graph shows the overallsystem activity during a program loop.7-1.6.7 Functional Measurements

Common functional measurementsinclude elapsed time of program execution for twosystems; elapsed time of execution for two programson the same machine; and an event-count for aparticular routine. These and similar measurementsprovide quantitative information as to the comparative

DIGITAL TROUBLESHOOTINGTECHNIQUES

Find in sequence: 024114Then: 024124Then: 024130Start: 024156

(Restart) on: 024160


AII

!;II

/’ I 02410FATH NO. I ‘“ //’ //

/’ /. / ’

/6;4112. “~.- , /

‘ii l

p41601,,

TFigure 7-22. A Complex Program With Branching Network

merit of instruments, efficiency of a software code andlikely sites of malfunction.7-1.6.8 Interaction with Other

InstrumentsWhen troubleshooting it is usually

convenient to use analog measurement tools inconjunction with the logic analyzer. Many logicanalyzers provide some form of trigger output based ona defined state of timing condition. The trigger outputis also useful for gating clocks, interrupting the systemactivity, triggering circuits, or halting the system atbreakpoints to permit static debugging. A commontroubleshooting technique is to pinpoint a faulty pieceof hardware through state flow analyses and then usethe trigger capabilities of the log analyzer to trigger anoscilloscope to study the waveform at that particularpoint.

7-1.7 MINICOMPUTERSMinicomputers basically fall into two

groups by virtue of operation: asynchronous and

7-20

synchronous. Asynchronous operation transmits signalsunder control interlocked “handshake’-’ (interrupt)signals. In synchronous operation, sequence oftransmissions is controlled by equally spaced cIocksignals.7-1.7.1 Asynchronous Operation

Typical of asynchronous systems is aDEC PDP-11 which uses a single 56-line unibus forcommunication between the CPU, memory, and anyperipheral devices. Communication between devices isdefined by the sequence of states on a set of inter-locked unibus lines, termed the “handshake” (inter-mpt) sequences. A priority of “handshake” (interrupt)sequence sets the master-slave relationship at anygiven time and specifies what type of informationis being passed, and where. Another asynchronoussystem is the DEC LSI-11. While the PDP-11 unibushas separate address lines, the DEC LSI-11-Q-BUSmultiplexes address and data on the same lines. Figure7-25 is a typical example of a system which operatesasynchronously.


L

L

L

——.TECHNIQUES

Table 7-5. List Display Data Format

.----------------------------------------------------TRACE------------LIST------------------------------------TRACE----------C OMPLETE --------------------------

LABEL A D F TIMEBASE OCT OCT BIN DEC

-09 01010 177777 1 .3 u s-08 01004 027003 0 1.3 u s-07 01002 037001 0 1.9 u s-06 01010 177777 1 1.0 us-05 01010 000000 0 .4 u s-04 01004 103501 0 1.5 us-03 00000 000000 0 2.3 us-02 01007 001300 0 1.0 us-01 01006 027000 0 2.9 us

CENTER 01000 103601 1 2.6 us+01 00000 000020 0 1.3 u s+02 01000 063010 0 1.3 us+03 01010 100000 0 1.0 us+04 01002 073011 1 .9 us+05 01010 100000 0 1.1 us+06 01002 037011 0 1.2 us+07 01010 100000 1 1.0 u s+08 01010 100001 1 .4 us+09 01004 027003 0 1.2 us+10 01002 037011 0 2.0 u s

7-1.7.2 Synchronous OperationSystems that opera te synchronously

employ a system-timing generator. These usually con-sist of two buses: a higher speed memory bus, and aslower speed INPUT/OUTPUT bus for peripherrdequipment. An example of a synchronous system (theHP 21 MX) is shown in Figure 7-26. As withasynchronous systems, signal path is determined by thesequence of states on the control lines, but the time ofdata transmission is set by defined cycles of time.

7-1.8 SETTING UP THELOGIC ANALYZERThe first step in viewing activity on a mini-

computer equipped with a logic analyzer is connect-ing the system to the analyzer. The technician has theoption of connecting 24 to 36 individual leads, butthis procedure ‘is time-consuming and is prone to error.A much more convenient way to connect the systemand the analyzer is to use a dedicated interface. Mostcompanies offer interfaces for the more popularminicomputers, such as the PDP-11. Some companiesalso offer a general purpose probe interface, such as theHP 10277. The prolxe interfaces include interchange-able wire-wrapped boards that allow the technician to

7-21

choose the address, data and/or control lines he wishesto monitor. It is desirable, and sometime necessary, toprocess signals to the logic analyzer. The PDP-11unibus, for example, does not have a distinct clock-signal associated with address or data lines, thereforeit operates asynchronously using “handshake” (inter-rupt) signais. A dedicated interface, the HP 10275APDP-11 unibus interface derives a logic analyzer clockwith decoding circuits or interrupt signals. Some signalpreprocessing is accomplished directly on the interfaces.

7-1.9 STATE FLOW ANALYSISState flow measurements illustrate tech-

niques for monitoring a complex program execution interms of rerd time. For the examples that follow,the measurement analyzer combines a HP 161OA LogicAnalyzer with the DEC PDP-11 Minicomputer con-nected with two interfaces: the HP 10275A unibusinterface and the HP 10277A Opt 001 General PurposeProbe Interface.7-1.9.1 Basic State Flow Measurement

The simplest measurement involves col-lecting and displaying an in-line code during programexecution. The analyzer display is called a “tracelist.” A line-by-line comparison of a HP 161OA trace

ORIGINAL

DIGITAL TROUBLESHOOTINGTECHNIQUES

MSYN

SSYN

HLTRo

I NIT

B8sY

BR4

TIME DIAGRAM

EXPAND INM2NT)RGLITCH DISPLAYMN3NlFlCATK)N


❑ TRACE ABORTED

❑5NS /CLKIUS/ DIV

El mElEl n n n r-l r–ElEl rElEl u u u

~TRIGGER EVENT-1

Figure 7-23. Timing Diagram

‘---- ----TRACE GRAPH --------------- -- ------–----------TRACE COMPLETE

OFF SCALE DATA

U P P E R L I M I T ~ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -~;

, ,’,

i ’t !’

/’/“

/, ,, /’,’ ,’ ,, I,,’

/ ,’ ~ ,’/’ ,’ “ ,f,, ,’,’, ,{ .’ ,/’

,’

LCMER L I M I T ~ ’ - - - - - - - - - - - - - - - -_ - - - – - - - - — _ _ _ - - - - - — - - -

@zl

Figure 7-24. Graph Mode Display

list and the program assembler listing will show any-thing inconsistent between what is expected and whatactually occurs. The appropriate variables are set inthe Format and Trace Specification menus (Figures7-27 and 7-28) to produce a simple trace list, begin-ning at the start of the start-up routine of Figure7-29. The resultant trace list (shown in Table 7-6)begins with the initial address 20008, and containsthe next 63 states in program execution. Twenty lines

7-22

of state flow are shown on the analyzer at a time;the roll keys are used to view the other states of thetrace list that are contained in the logic analyzer mem-ory. A comparison of the trace list and the programlisting will confirm that the program is executingproperly. HP 161OA Logic AnaIyzer Format Specifica-tions selected for monitor the PDP-11/04 sets 16channels for address and 16 channels for data, all inoctal base (Figure 5-27). Figure 7-28 is the Trace

ORIGINAL

L

L

GENERAL MAINTENANCE NAVSEA SEOOO-OO-EIM-160 DIGITAL TECHNIQUESTECHNIQUES

I I FMRALLELCPU MEMORY INPUT/OUTPUT

IUNIBUS 56 LINES TERMINATOR

I I

d=l : ‘MEMORY SERIALINPUT/OUTPUT

+ ●

Figure 7-25. Example of an Asynchronous System

E!El&lem+l—

d s-Bus *

C P UCH%kEL

PORT

I N P U T / O U T P U T B U SCONT~LER

* >

E&l&le of a Synchronous System
Figure 7-26. Examp
Specification for making a simple trace beginning at

address 0020008, and listing 64 sequential states.Using the trace specification shown in Figure 7-28for the start-up routine of Table 7-6 results in a simple,in-line trace list of the program execution.7-1.9.2 Graph Overview

Another method of viewing programexecution on the HP161OA Logic Analyzer is thegraphic display. Figure 7-29 is the graphic display ofthe first 64 addresses of the startup routine (Table 7.6).Each point of the graph represents one of the sixty-four addresses (iabel a). Notice that the limits of thegraph have been Set at 20008” and 30008, the limitsof the addresses used in the routine which makes

ORIGINAL 7-23

viewing and interpreting easier. The points cor-responding to the twenty states shown in Table 7-7 areintensified in the graphic display mode. Figure 7-29is an example of the HP 161OA in graphic displaymode when used with the startup routine defined byTable 7-6. Reading from left to the first twenty pointscorrespond to twenty states displayed in Table 7-7and these points are intensified. In actual practice itis not always possible to specify in advance the sixty-four consecutive states that contain a subtle faultthat causes a program to fail or get lost, a larger over-view is needed. This can be done by viewing a sampleof every single, every second, every fifteenth state orany state selected. As an example, Figure 7-30 is

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-00-EIM.160TECHNIQUES

GENERAL MAINTENANcE

–- --- -FORMAT SPECIFICATION---- - .TRACE ABoRTED - - - - - — - - — — -

CLOCK SLOPE ~(+-)

LABLE ASSIGNMENT(A, B, C, D,E,F, X )

LABLE

LOGIC POLARITY(+-)

NUMERICAL BASE(BIN, OCT, DEC, HEX)

POD 4 POD 37

POD 20

POD I- - - - - - 7 - _ - - _ - o 7__----o 7_--__–cl

[AAAAAAAA[ IAAAAAAAAI IDDDDDDDDI IDDDDDDDD1ACTIVE CHANNELS

& &

ml ml

Figure 7-27. Format Specification Menu

-------TRACE spE(JFlcATlc)N ------------------- ---- TRACE ABORTED -------------------- --------LABLE A D OCCURBASE OCT OCT DEC

TRACE

I ALL STATES I

COUNT ~Figure 7-28. Trace Specification Menu

4

a graph of every fifth state of the same program,giving the technician an overview of activity across320 states (5 x 64). The upper limit has been changedto 51008, thus showing the jump to an output routineat address 50008. By changing the occurance count

7-2

on the trace specifications the technician can compressthe graph by one ratio from 1:1 to 65,536:1, for agraph of program activity in sixty-four states to overfour million states. Figure 7-30 shows an exampleof an expanded graph showing a discontinuity as the

4 ORIGINAL

L

GENERAL MAINTENANCE NAVSEA SEOOO-00-EIM-160 DIGITAL TROUBLESHOOTINGTECHNIQUES

/--------------TRACE GWPH-------------TWCE-COMPLETE---------------------- \

UPPER LIMIT I-------------------------------------003000 I

IIII

GRAPHED LABEL [AlLABEL BASE OCT

LOWER LIMIT002000

,1 ,l,@#,ns * , I- *’ “ ‘ s “ “ “ ““,*m* * , *

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Figure 7-29. Graphic Display of First64 Addresses ofStartup Routine

L

program jumps tothe output routine ataddress 5000~.Every fifth state of 320 states is shown asapointo~the graph.7-1.9.3 Measurements From

aGraph ModeThe twenty intensified pointa depicted

in Figure 7-30 correspond to the twenty states ofTable 7-8. By centering these points areound theapparent discontinuity of Figure 7-30 and thenswitching to the trace list of Table 7-8 a jump willtake place after address ()()21268, line 16. Becausethe graph was of every fifth state, the trace specifica-tion is changed to trace all states begining the tracebefore the suspect address and ending it after it. Thuscentering the trace around the suspect address. Anexample of this can be seen in Table 7-9. This givesa detailed list centering around the discontinuity. Byusing a few simple steps the technician can locate agross error and quickly narrow the field to a smallarea around the discontinuity. Using the abovedescribed technique,, the technician can rapidly findvery difficult problems.7-1.9.4 Measurements on Selected

Types of InformationWhen only one type of information is to be

collected analysis is greatly simplified. The operatormay have indicators that one 1/0 is malfunctioning,as a subroutine is suspect. Tracking only one kind of

ORIGINAL 7-25

information is achieved by display qualifications. Thetechnician selects for viewing only the transactionsthat pertain to what he is looking for, which makesyour troubleshooting more efficient and reduces therequired size of analyzer memory. One type of mea-surement requiring display qualification is the veritlca-

tion of data stored in the transmit buffer on the serial1/0. Continuing use of Table 7-6 compares the messagetransferred beginning at address 25008” to the displayshown in Table 7-7 as a check of the operation of theserial 1/0 channel. Changing the trace specification totrack only state addrew in the 0025XX8 field andsetting the amdyzer interface switch to write pro-duces the trace list of Table 7-10 which is comprisedtotally of write commands to the transmit buffer.Comparing this to the terminal display provides acheck on data transmission to that buffer. A secondexample of display qualification is that of checkingthe execution of a single routine in this case set thetrace specification menu to trace. Only states1775668, which is the address of the transmit bufferregister on the 1/0 port. Then set the qualifier switchon the analyzer interface to WRITE. The printout(Table 7-11) from the analyzer memory, (includingtranslation of data bits to Alphanumeric characters andthe display shown in Figure 7-31) sbould agree. Ifthese agree, then it can be safely assumed that the1/0 channel is working correctly.

DIGITAL ‘ROUBLESHOOTING NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCETECHNIQUES

Table 7-6. Program Listing Sample Startup Routine

WED, JUL 18, 1979, 10:30 AM

002000 010706002002 062706002006 010705002010 062705002014 010504002016 012725002022 012725002026 012725002032 012725002036 012725002042 012725002046 012725002052 012725002056 012725002062 012725002066 012725002072 012725002076 012725002102 012725002106 012725002112 012725002115 005205002120 010403002122 112300002124 004267

005776

000470

004015051120051505020123047101020131042513020131047524044440052116051105052522052120046440020105

002650

BEGN MOVR7,R6ADD*,R6MOVR7,R5ADD#h,R5MOVR5,R4Mov#nJR5)+Mov#nJR5)+Mov#ll~R5)+Mov#llJR5)+Mov#llJR5)+Mov#n4R5)+Mov#hJR5)+MOV*,(R5)+Mov#n,(R5)+Mov##h,(R5)+Mov#h’(R5)+Mov#hJR5)+MOV*JR5)+MOV%,(R5)+Mov#nJR5)+Mov#il,(R5)+INCR5

OVER MOVR4,R3MESS MOVB(R3)+R0

JSRA OUTT002130 020305 CMPR3,R5002132 001373 BNE MESS002134 000005 REST002136 012737 002600 000060 MOV#n,@#A002144 012737 000340 000062 MOV#n,@#A002152 012737 000140 177776 MOV#n,@?#A002160 012737 000100 177560 MOV#n,@#A002166 000001 WAIT002170 00167 177724 JMPA OVER

REFERENCE R6TOTHEPCSETTHESTACKPOINTER (7776)REFERENCE P5TOTHEPCPOINTTOISTADD. IN INTR. MESS. (2500)REFERENCEINTERRUPTMESSAGEISTADDRESSMOVE LF,CRTOINTERRUPT BLOCKMOVE R,PTOINTERRUPTBLOCKMOVES,E TOINTERRUPTBLOCKMOVE SB,S TO INTERRUPT BLOCKMOVE N,A TO INTERRUPT BLOCKMOVE SB,Y TO INTERRUPT BLOCKMOVE E,K TO INTERRUPT BLOCKMOVE SB,Y TO INTERRUPT BLOCKMOVE O,T TO INTERRUPT BLOCKMOVE L,SB TO INTERRUPT BLOCKMOVE T,N TO INTERRUPT BLOCKMOVE P,E TO INTERRUPT BLOCKMOVE U,R TO INTERRUPT BLOCKMOVE T,P TO INTERRUPT BLOCKMOVE M,SB TO INTERRUPT BLOCKMOVE SB,F TO INTERRUPT BLOCKADD ONE TO BLOCKSET R3 = INTERRUPT MESSAGE ADDRESSMOVE DTA BYTE TO XFER REG.OUTPUT DATA BYTE TO TERMINAL (5000)ALL BYTES OUT?NO, GET NEXT BYTERESET THE UNIBUSLOAD INTR TRAP CELL WITH ADDRESSLOAD NEXT CELL WI PRIORITYSET PROCESSOR PRIORITYTURN INTERRUPT ONWAIT FOR INTERRUPTSTART OVER (2120)

4

d

7-1.9.5 Complex State MeasurementsUsing Sequential TriggersThe HP1610 Analyzer allowstheentry

of up to seven words which must be formed in asequence prior to the initiation of the trace. Eachofthese seven words may be further qualified byspecifying the number of times that word is to appear(up to 65,536 times) before a search begins for thenext sequence term, or the trace is begun. Asequencerestart state may be used to restart the search for thetrigger works if the desired sequence does not occurbefore this reset condition is met. These twotechniques are most commonly used when tracingmultipath programsor nested loops.

7-26

7-1..9.5.1 Tracing Multipath ProgramsIt is a rare minicomputer program that

doesn’t include at least one branching network. InFigure 7-32, the beginning address of the outputroutine for an interrupt 21288 can be reached bythree paths. Suppose the technician is only interestedin this routine when it occum after address 27148.With sequential triggers this can be done simply bylisting address 2714 and 2120 as the only two termsto be found in sequence. The trace specificationmenu for this condition is illustrated in Figure 7-33and simply lists the two addresses, each occuring once.The trace list will show the two sequential terms andlist the subsequent states. Should the technician

ORIGINAL


L

Table 7-7. Trace List of First Twenty Statesof Program

------------TRACE LIST------------TRACE-COMPLETE--------

LABELBASE

START+01+02

+03+04+05+06+07+08

+09+10+11+12+13

+14+15+16+17

+18+19

AOCT

002000002002002004002006002010002012002014002016002020002500002500002022002024002502002502002026002030002504002504002032

DOCT

010706062706005776010705062705000470010504012725005015005015

012725051120051120051120012725051505051505051505012725

TECHNIQUES

/------------TRACE GRAPH-------------TOFF SCALE DATA

UPPER LIMIT I -005100 I

II

GRAPHED LABEL [Al ILABEL BASE OCT II1

IiIT

i1

LOWER LIMIT 1,,,, !002000 I---

L Figure 7-30. Graphic Display of Startup Rou

ORIGINAL 7-27

wish to review the states occuring between the twosequential terms, change the trace specitlcation menufrom Start mode to Center mode. In the trace listshown in Table 7-12 only four states occured betweenthe two terms. It is obvious with the option of upto 7 trigger words it is easy to specify only the branchof interest.7-1.9.5.2 Tracing Nested Loops

The capability for sequential triggersis also a convenient feature when analysis of infor-mation contained in nested loops is desired. Anexample of this can be found in the Figure 7-34. Oneroutine writes a space and all 94 printable ASC1lcharacters to the terminal as shown in (Table 7-13).Every time the major loop is executed once (J), theminor loop (K) is executed 94 times. For an exerciseconsider how best to trace program execution followingthe 36th occurrence of the K loop during the 5th pass ofthe J loop. Most logic analyzers have a trigger delay,therefore the number of states to be skipped follow theoccurance of a triggered word. Then using a littlearithmetic one can trace the desired portion of pro-gram execution by using a trigger address of 200628,and a trigger delay of 412 states [(4 x 94) +36], this isonly valid assuming the loops are of equal length. Abetter way exists to use sequential triggers, as is shownin Figure 7-35. The logic analyzer being used willbegin ita search at address 2000018, outside the

MCE-COMPLETE----------------------

--------J-J-J--J--’--J--J---J--’--’--’--u m , ,, u, ,,, m u, .,} ,,, .,, ,,,

d ,, “ ,

----------------------------------

\

tine Displaying Discontinuity at Jump

DIGITAL TROUBLESHOOTING NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANcE---- . . . . . . .--I tUHNILIUtS

Table 7-8. Trace List Display Discontinuityin Program Execution

.-----------TRACE LIST------------TRACE-COMPLETE--------

LABEL A DBASE OCT OCT

+07+08+09+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26

002046002054002520002522002072002100002532002534002116002126177566005004005006177564005010005004005006177564005010002122

01272502013104752404444001272505252205212004644000520500265000001510573’Z177564000000100375105737177564000000100375112300

Table 7-9. Trace List Center Around Discontinuity

-----------TRACE LIST------------TRACE-COMPLETE-------

LABELBASE

-09-08-07-06-05-04-03-02-01

CENTER+01+02+03+04+05+06+07+08+09+10

AOCT

002112002114002536002536002116002120002122002500002124002126007776005000005002177566177566005004005006177564005010005004

DOCT

012725020105020105020105005205010403112300005015004267002650165054110037177566000000000015105737177564000000108375105737

Table 7-10. Trace List Containing OnlyWrite Instructions

----------TRACE LIST----------TRACE-IN PROCESS ----------WARNING-SLOW CLOCK


START 177566 000015+01 002500 005015+02 002502 051120+03 002504 051505+04 002506 020123+05 002510 047101+06 002512 020131+07 002514 042513+08 002516 020131+09 002520 047524+10 002522 044440+11 002524 052116+12 002526 051105+13 002530 052522+14 002532 052120+15 002534 046440+16 002536 020105+17+18+19

/-28

4

loops, passing the initial address of the major loop5 times and then traces the program execution afterthe address of the minor loop is passed 36 times. Notethat in this case occurances of the address of the minorloop are counted. The resulting trace (Table 7-13)shows the count of occurances of address 20062 inthe right hand column. The first count, 376 (4 x 94),shows that four complete passes of the major loopoccurred before the 36 passes of the minor loopwas counted. Sequential triggers make it simple totrace information deep in the nested loops of fixedor variable length without the bother and potentialerrors of using trigger delay and “simple” arithmetic.7-1.9.6 Measuring Execution Time

The count time measure is especiallyusetld for benchmark tests to check for programefficiency. As an example, the 1/0 service routineshown in Figure 7-36 can be evaluated using timemeasures available on a 1610 logic state analyzer.This routine moves a 12 character string to a buffer,then moves the characters one by one to a terminal,with 150ns between each transmission. The tracespecification menus (Figure 7-37) is set to count time,and the time count is set to relative on the associatedtrace list (7-14). Relative time counts are listed foreach state, and each time is measured between thestak and the preceding listed state. Table 7-15

ORIGINAL


b

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Table 7-11. Trace List of all Write Instructions toOutput Buffer with Translation ofData to Alpha Numeric Code

.--------------------TRACE LIST--------PRINT-IN PROCESS--

,ABEL A DIASE OCT OCT

;TART . . . 177566. 000114 . . . L+01 177566 000040 SP+02 177566 000062 2+03 177566 000060 0+04 . . . 177566 ..000060.. . . . . . . . . 0+05 177566 000060 0+06 177566 000015 CR+07 177566 000015 CR+08 . . . 177566 ..000012.. . . . . . . . . LF+09 177566 000044 $+10 177566 000000 NUL+11 177566 000123 s+12 . . . 177566. .000015.. . . . . . . . . CR+13 177566 000015 CR+14 177566 000012 LF+15 177566 000120 P+16 . . . 177566 ..000122.. . . . . . . . . R+17 177566 000105 E+18 177566 000123 s+19 177566 000123 s+20 . . . 177566 ..000040.. . . . . . . . . SP+21 177566 000101 A+22 177566 000116 N+23 177566 000131 Y+24 . . . 177566 ..000040.. . . . . . . . . Sp+25 177566 000113 K+26 177566 000105 E+27 177566 000131 Y+28 . . . 177566 ..000040.. . . . . . . . . SP+29 177566 000124 T+30 177566 000117 0+31 177566 000040 SP+32 . . . 177566 ..000111.. . . . . . . . . I+33 177566 000116 N+34 177566 000124 T+35 177566 000105 E+36 . . . 177566. .000122.. . . . . . . . . R+37 177566 000122 R+38 177566 000125 u+39 177566 000120 P+4(I . . . 177566 ..000124.. . . . . . . . . T+41 177566 000040 SP+42 177566 000115 M+43 177566 000105 E+44 . . . 177566 ..000040.. . . . . . . . . SP+45 177566 177640+46+47+48

TECHNIQUES

$L2000$sPRESS ANY KEY TO INTERRUPT ME

\

Figure 7-31. Display ofOutput Routine

PATH A PATH B PATH C

Figure 7-32. Example of Multipath

ORIGINAL 7-29


--------TRACE SPECIFICATION---------TWCE-C~pLETE----------------------

LABEL OCCURBASE O:T ~T DEC

FIND IN SEQUENCE 002714~02120 ;;;;[; w;;:[START] TRACE

SEQ RESTART [OFF]

TRACE[ALL STATES]

COUNT [ OFF ]

/

Figure 7-33. Trace Specification ofPath ‘An

Table 7-12. Trace Listas Specified by Figure 7-33

-----------TRACE LIST------------TRACE-COMPLETE--------


-09-08-07-06

SEQUENCE 002714 000002-04 007774 002170-03 007776 000140-02 002170 000164-01 002172 177724

CENTER 002120 010403+01 002122 112300+02 002500 005015+03 002124 004267+04 002126 002650+05 007776 165054+06 005000 110037+07 005002 177566+08 177566 000000+09 177566 000015+10 005004 105737

/-30

I 20000

Figure 7-34. Example ofa Nested Loop

ORIGINAL


L

Table 7-13. Trace List of a Nested Loop

-----------TRACE LIST------------TRACE-COMPLETE--------

LABEL A D STATE COUNTBASE OCT OCT DEC

[R E L]

EQUENCE 020000 012737EQUENCE 020030 005000 376START 020062 005200 36

+01 020064 00764 0+02 020036 110037 0+03 020040 177566 0+04 177566 000000 0+05 177566 000104 0+06 020042 105737 0+07 020044 177564 0+08 177564 000000 0+09 020046 100375 0+10 020042 105737 0+11 020044 177564 0+12 177564 000000 0+13 020046 100375 0+14 020042 105737 0+15 020044 177564 0+16 177564 000000 0+17 020046 100375 0

TECHNIQUES

--------TRACE SPECIFICATION-------

LABEL D OBASE O:T OCT

FIND IN S; N&NCE 020090 XXXXXX 09021?E13fI XXXXXX 99

[START] TRACE o2L3062 XXXXXX 13

SEQ RESTART [OFF]

TRACE[ALL STATESI

COUNT [STATE] 020062 XXXXXX

Figure 7-35. Trace Spe

ORIGINAL 7-31

shows the same trace list with an absolute (ABS)time measure, and all times are measured from zeroat the trace point.7-1.9.7 Locating Intermittent Errors

Most experienced technicians realizethat the intermittent problem is the most difficult ofall to find. Results from the error could show up fardownstream from the error, and the original problemmay be missed. The HP 1610 analyzer has a tracecompare mode which can be applied in situationswhere an error condition occurs sporadically. Firstthe likely location of the error is defined, and a traceis made of a program segment which is known to beexecuting properly (Table 7-16). The correct traceis stored in the analyzer memory. The 3 choices forsubsequent traces, are OFF, STOP=, or STOP#. Usingthe “stop if not equal” (STOP#) operation, so long asa new trace is the same as the stored trace, the displayshows zeros (Table 7-17). If the new traces does notcompare to the stored one Table 7-16; the analyzerhalts and the display of Table 7-18, will con-tain non-zero numbers. These numbers, whenconverted to binary numbers specify whichbinary bits are nonmatching. For example inTable 7-18, line 10 is 348. Converted to binary,0000348 = 0000000000011100, and bits 2, 3, 4 ofline 10 of the new trace do not match the cor-responding bits of line 10 of the stored trace list.

--TWCE-COMPLETE----------------------

CCURDEC

!301995

PL136

/

cification of Loop K


2 6 3 0 $

&2664

WAIT 150ms

*

2674OUTPUT

HARACTERz2704

CHi&$ER ‘ “

YES2706

RESETPOINTER

Figure 7-36. Example of Input/OutputService Routine

-------TRACE SPECIFICATION-----. -

LABEL OCBASE O:T O:T D

FIND IN SEQUENCE 002630 XXXXXX 000THEN 002664 XXXXXX 000THEN 0~2674 XXXXXX 0@0THEN 1302704 XXXXXX 000

[START] TRACE 002706 XXXXXX 000

SEO RESTART [OFF]

TRACE[ALL STATES]

COUNT [TIME]

Figure 7-37. Trace Specificati

7-32

7-1-1o TIMING ANALYZERSMost problems in a digital system can

be located with state flow analysis techniques. How-ever, there are problems that are best found throughanalysis of the timing of the various signals. Timing isoften the most crucial factor in difficulties relatedto interface and control, glitches, clocks, phasing andsimilar problems. To illustrate the use of a logicanalyzer in timing analysis, three examples of commonmeasurement are given. For measurements on controllines and glitch detection a HP 1615A is used.7-1.10.1 Analysis of Timing Relationships

of Control LinesA system crash always demands

immediate attention and resolution. In this example,each time a program is started at address 600008,the processor halts and the run light extinguishes.Anafysis of both address and control lines is required.The first step to be taken is to connect the analyzer tothe minicomputer in question. This may be accom-plished many ways, but for this example we will beusing an interface adapter. Pods 2 and 3 will be usedfor the 16 bits of address and pod 1 will be used forcontrol lines. Pod 1 will be labeled in accordance withTable 7-19. For this example the format specificationmenu and the trace specification menu are shown in

.--TWCE-COMPLETE ---------------------- ----

CUREC

0101L310101

on Menu for Figure 7-34

ORIGINAL


Table 7-14. Trace List of Figure 7-44 withElapsed Time Displayed

---------TRACE LIST------------TRACE-COMPLETE----------

LABEL A D TIMEBASE OCT OCT DEC

[R E L]SEQUENCE 002630 01O5O3SEQUENCE 0 0 2 6 6 4 012701 40.9 usSEQUENCE 002674 112300 1 4 6 . 6 M SSEQUENCE 0 0 2 7 0 4 001367 86.8 us

START 002706 005005 1.614 S+01 02710 062705 2.5 US+02 002712 002542 1.4 US+03 002714 000002 2.8 US+04 007764 002170 1.5 us+05 007766 000140 1.6 US+06 002170 000167 2.1 US+07 002172 177724 1.4 us+08 002120 010403 2.3 US+09 002122 112300 2.8 US+10 002500 005015 1.5 us+11 002124 004267 2.5 US+12 002126 002650 1.4 US+13 007766 165054 1.9 us+14 005000 110037 2.8 US+15 005002 177566 1.9 US ~

Table 7-15. Trace List of Figure 7-44 withAbsolute Time Displayed

----------TRACE LIST------------TRACE-COMPLETE----------

LABEL A D TIMEBASE OCT OCT DEC

[ABS]SEQUENCE 002630 010503 - 1.760 SSEQUENCE 002664 012701 - 1.760 SSEQUENCE 002674 112300 - 1.614 SSEQUENCE 002704 001367 - 1.614 S

START 002706 005005 0 u s+01 002710 062705 + 2.5 US+02 002712 002542 + 3.9 US+03 002714 000002 + 6.7 US+04 007764 002170 + 8.2 US+05 007766 000140 + 9.8 US+06 0 0 2 1 7 0 0 0 0 1 6 7 + 1 1 . 9 U S+07 0 0 2 1 7 2 1 7 7 7 2 4 + 1 3 . 3 U S+08 0 0 2 1 2 0 0 1 0 4 0 3 + 1 5 . 6 U S+09 0 0 2 1 2 2 1 1 2 3 0 0 + 1 8 . 4 U S+10 0 0 2 5 0 0 0 0 5 0 1 5 + 1 9 . 9 U S+11 0 0 2 1 2 4 0 0 4 2 6 7 + 2 2 . 4 U S+12 0 0 2 1 2 6 0 0 2 6 5 0 + 2 3 . 8 U S+13 0 0 7 7 6 6 1 6 5 0 5 4 + 2 5 . 7 U S+14 0 0 5 0 0 0 1 1 0 0 3 7 + 2 8 . 5 U S+15 0 0 5 0 0 2 1 7 7 5 6 6 + 3 0 . 4 U S

TECHNIQUES

Table 7-16. Trace List of Reference

--------TRACE LIST-------------STORE-COMPLETE-----------

LABEL ABASE OCT

START 002600+01 002602+02 177560+03 177560+04 002604+05 002606+06 177562+07 002610+08 002612+09 002614+10 002622+11 002624+12 002626+13 002630+14 002632+15 002634+16 002400+17 002400+18 002636+19 002640

Table 7-17. Trace List of Good Compare

-----TRACE COMPARE----------COMPARED TRACE ------

LABEL A COMPAREDBASE OCT TRACE MODE

[STOP #]START 000000

+01 000000+02 000000+03 000000+04 000000+05 000000+06 000000+07 000000+08 000000+09 000000+10 000000+11 000000+12 000000+13 000000+14 000000+15 000000+16 000000+17 000000+18 000000+19 000000

ORIGINAL 7-33

DIGITAL TROUBLESHOOTiNG NAVSEA SEOOO-OO-EIM-160 GENERAL MAINTENANCETECHNIQUES

Table 7-18. Trace List of Bad Compare

-----TRACE COMPARE--------COMPARED TRACE -------

LABEL A COMPAREDBASE OCT TRACE MODE

[STOP #]

START 000000+01 000000+02 000000+03 000000+04 000000+05 000000+06 000000+07 000000+08 000000+09 000000+10 000034+11 000004+12, 022626+13 022632+14 022636+15 002654+16 002460+17 022406+18 022626+19 022652

Table 7-19. Contents of Pod-1

Bit O — MSYNBit 1 — SSYNBit 2 — HLTRQBit 3 — INITBit 4 — BBSYBit 5 — NPRBit 6 — BR4Bit 7 — Spare

FORMAT SPECIFICATION TR

MODE [16 BIT 8 B

CLOCK SLOPE [+1 LSB~

7- - - - - - p 7LABEL SELECT AAAAAAAA AA

(A, B,C,X) ~M;B

LOGIC POLARITY [+]BASE IOCT]

POD1

LABEL SELECT k-iiii!

‘D’E’X) /~Bt

~E

\LOGIC POLARITY [+]

BASE [BIN]\

Figure 7-38. Format Spe

7-34

Figures 7-38 and 7-39, respectively. If the programwere executed properly the sequence of control eventswould be as shown in Table 7-20. As shown byFigure 7-39, the trace list is generated so it is evidentthat the trigger address 060000 is never reached. Whilestill in this post crash state, it may be worthwhileto look at the control lines. This is accomplished bychanging the mode of the analyzer to timing andusing any event labeled (Figure 7-38) as a trigger.This results in a display as shown in Figure 7-40.Examining Figure 7-40, we can see that line 2,HALTREQUES (HLTRQ) is a HI, which of coursehalts the program. The next problem is why did theHLTRQ go HI. Choosing “END MODE” and triggeringa HLTRQ will display the events that took place priorto HLTRQ going HI. When the test is run again, the

ACE-ABORTED

IT] UNIBUSADDRESSLINES

- - - - - - gAAAAAA

J

=:::

i:BUSBUSBus

MSYN HSSYN HHLTRQ HINIT HBBSY HNPR HBR4 H

spARE

cification Layout

ORIGINAL


E;;;;aA DELAY

OCT DEC

060000 000000

(

CLOCK QUALIFIER XXXXXX

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

START TRACE INT CLOCK 5fJNs/cLK

FIRST MEMORY TRANSACTION OF THETARGET pROGRAM. (SEE TOP FRAME OFTHIS PAGE.)

Figure 7-39. Trace Specification MenutoInitiateat060008

Table 7-20. Sequence of Program Execution-

1. -060000 isbroughtupon the ADDBUJ2. MSYNFlagissetbyCPU3. Dataisputon theBUS4. SSYNFlagissetby R O M5. CPU reads data6. MSYN Flag is cleared by CPU7. SSYN Flag is cleared by ROM

MSYN

SSYN

BBSY

BR4

TIMING DIAGRAM TRACE-CWIPLETE

EXPAND INDICATOR [ONI 5pNs/cLKGLITCH OISPLAY [ONI IUS/DIV

fWGNIFICATION [X11 [750 NS]

121

~AssERTEcI HALT REQUESTI

A

I 7

Figure 7-40. Timing Diagram of Control LinesAfter Program Failure

I TIMING DIAGRAM TRACE-COMPLETE

‘Xwi%h’:!$::! [8/1 4250Ns L K5U ?DIV

MAGNIFICATION CXI 3 c 21 sum,

“~

•~

HI151

I

ElI

❑

Figure 741. Timing Diagram of Control LinesBefore Program Failure

the timing display shown in Figure 7-41 indicates thatline 2(HLTRQ) is a HI. Notice lines O(MSYN) and1(SSYN); line MSYN was set by the CPU but no re-sponse comes from ROM(SSYN). The minicomputerused as the example will declare a timing fault andhalt if tbe SSYN flag is not set within 20 microsec-onds of the MSYN flag being set. In the minicomputerued as an example the ROM circuit has a special clockcontrol circuit to compensate for its long memoryaccess time. This circuit consists of an adjustable oneshot. By connecting the spare line (line 2) to theoutput of the one shot, and repeating the test it givesthe display shown in Figure 742. Then the time of theoneshot can be measured using the cursor on theanalyzer. In this example the output of the one shotis shown to be 21.8 microseconds; this exceeds the20 microseconds allowed and therefore the CPUdeclares a timing fault and sets halt request. By

fiD In 1 NI A I

adjusting the one shot to 20 microseconds solves theproblem, and only four steps were required to findthe problem.7-1.10.2 Glitch Detection

A Glitch is defined as a transient signalthat if it is of sufficient amplitude and duration will


TIMING DIAGRAM TRACE-COMPLETE

EXPANQ- INOICATOR C O N 3!!?”

25 NS/CLK.AY CON3ON CX I 3 21.[

GLITCH DISPL ls/DlvMAGNIFICATI(

“’mm

/.

21

1 9

131I ,

El n] /

Figure 7-42. Timing Diagram of ControlLine with Cursor

MSYA

SSYN

HLTRO

INIT

BBSY

NPR

BR4

SPARE

TIMING DIAGRAM TRACE -COMPLETEEXPAND INDICATOR CON3

GLITCH DISPLAY cONJ 5~&~KMAGNIFICATION C Xl 3 [email protected]

‘~,

El HILTROA S S E R T I O N

=

❑iI

“-JEl

d,

NOTHING ABNORMAL 1

Figure 743. Timing Diagram of Control LinesTriggering on HLTRQ Line

T,MINGDIAGRAM =%=TEEXPAND INDICATOR CON3GLITCH 13SPLAY CON3MAGNIFICATION Cxl 3

YNa TRIGGER EVENT+ n

SY ~mnvmi-Ra 1

9WE$MWLURE4 1 6 1

.0 ❑

DELAY 15 SE: k7~

Figure 7-44. Timing Diagram DisplayingAssertion of AC-LO Flag

4

cause the system to malfunction. Using the previousexample, an analysis will be made of a differentproblem. In this example a terminal rewire routineis interrupt driven and is entered by pressing any keyon the keyboard. The problem in this example is thatevery time a key is pressed the program halts. Totroubleshoot this problem the setup and proceduresof the preceding problem are used, and as before adisplay of the quiescent states of the control linesfollowing the halt shows tht the HLTRQ flag has beenset. This time triggering on the HLTRQ line oneviewing the preceding activity on the control linesreveals no abnormal conditions (Figure 7-43). Acapability for both state and timing analysis is aparticular advantage for troubleshooting problemslike this. The sequence of events suggests that a glitchcould be involved, but an er ror in sof twareshould not be overlooked. The HP 1665A Logicanalyzer defines a glitch as multiple transitions accrossthe threshold between sampling periods. If a glitchoccurs it appears as a vertical bar, brighter and widerthan the timing marks, and can be easily distinguishedeven if it occurs at a timing transition. For thisanalysis, the next step is to check the activity oncontrol and address lines before HLTRQ is set. Anexample of this is given in Figure 7-44 using tracespecification of Figure 7-45 format specificationof Figure 7-46. The timing measure triggers the statemeasure, and the activity preceding the trigger

7-36

is to be displayed. The timing diagram shows noabnormal activity on control lines monitored, but thetrace list (Table 7-21) shows the address of powerfail trap cells, 0000248 and 0000268, on line 252and 253. In normal operation whenever the power

ORIGINAL


Table 7-21. Trace List Display of Power Fail Trap Cells

-T’’”’”=TRACE SPECIFICATION TRACE-CO!PLETE

/ bTIhUN*[8 BIT TRIGGERS 16 BIT] -STATE

[ END I TRACE

(NEGATIVETIME ON

(

BOTH

CLOCK QUALIFIER XXXXXX

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 [ END ] TRACE [IN:] CLOCK 50NS/CLKID::l; 1

BIN[ ON 1 XXXXXXIXX [Mit:;][ OFF ][ OFF 1 TRIGGER

ANO GLITCH 76543210 OURATIONON ANY OF [-------1 [> 15NSI

Figure 7-45. Trace Specification Menu Triggeredon End of Trace

(FO RMAT SPECIFICA TIO N TRACE-CONpLETE

ICLOCK SLOPE [+1

e~ POD3 PO02m 7---- ~-g 7------P

‘A!k:::::!’.ys:l:::u’

LOGIC POLARITY [+1 LINESBASE IOCTI

{

Pool7 - - - - - - 0

g LABEL SELECTLEEEEEEEE,F (D,E,x) SAME ASc ‘~ABOVE

LOGIC POLARITY [+1BASE [BINI

Figure 7-46. Format Specification Menufor Both State and Timing

L

TRACE LIST TRACE-COMPLETE[16 IT]

LINE A “NO OCT

241242243244 000000245 000000246 002276247 002274248 000060249 000062250 002272251 002270252 000024253 000026254 000000255 000024

drops below a specified level, either the AC LOor DC LO signals (generated by one shots) are setand the CPU automatically goes to a power failureroutine at location 0000248 to isolate the reasonfor the entry to the power failure routine we will

ORIGINAL 7-37

attach the AC LO line to the spare input of theanalyzer. The trace specification menu is altered toset a time delay of 15 microseconds to display activitybefore and after the trigger on the setting of HLTRQflag. Resuming the test and viewing the timing diagram(Figure 7-46) shows that a power fail signal does occuron the AC LO line. This signal only occurs after theinterrupt from the terminal and coincides with thebus request for interrupt on the BR-4(line6). Thetwo signals are of unequal duration, which suggestthat they are related, but not tied together. Two likelycauses are 1) a wiring glitch on the input to the ACLOone shot. Figure 7-47 shows this being done and alsoshows a glitch on the input line to the one shot whichoccurs at the same time as interrupt from the terminalon line 6. A more detailed view (Figure 7-48) is gainedby expanding the sweep with the time ten (x 10)magnifier, confining the concurrence of the glitchand the interrupt. In this example the glitch wascaused by capacitive coupling between the two linescrossing the halt. The problem can be corrected byreducing the capacitance between the two lines. Theinteractive use of time and state traces reduces a com-plex problem through a short series of logical steps,each more narrowily defining the range of likelyproblem areas.7-1.10.3 Asynchronous Measurement

with a Logic State AnalyzerThe first two examples of timing

analysis used the HP 1615A which perform both


TIMING DIAGRAM TRACE-COMPLETE

EXPAND INOICATOR CON ZGLITCH DISPIAY EON 3MAGNIFICATION CXl 3

,;=#%~

❑ [

❑1

❑I

❑

“.

Figure 7-47. Timing Diagram Displayinga Glitch on Line 5

TIMING DIAGRAM TRACE-COMPLETE250 NS/CLK

GLITCH DISPLAY CON3 500 NS/DIVMAGNIFICATION CXj03 C 40 5uS3—

❑ nI❑

I

Figure 7-48. 10x Magnification of Figure 7-47

--------FORMAT SPECIFICATION--------TRACE-A_____D_______

CLOCK SLOPE [ ](+,-)

POD PO04PROBE 7------0

LABEL ASSIGNMENT(A,6,c,D,E,F, x)

LABELLOGIC POLARITY [:] [!]

(+, -)

IPO03 PO02 POD1

7------0 7------o 7----.-o

AAAAAMA BCODEEFX XXXXXXXX

ACTIVE CHANNELS

I

iUMERICAL BASE(BIN, OCT, DEC, HEX)

IOCTI [BIN] [BIN] [BIN] [BIN] [BIN]

I

Figure 7-49. Format Specification to Assign Labels

Table 7-22. Controlling Labels

MYSN(label B) HLTRQ(labelE)SSYN(label C) ACLOOabelE)BR4(labeID) BBSY (label F)INTROabel D)

“kir--A ) I------ -TRACE SPECIFICATION- --- ---TRACE-ABORTEO -----

D E F OCCURBASE OCT BIN B:N BIN BIN BIN DEC

FIND IN SDJUUNCE WO& ~ 0 XX XX x 00001

THENf xx xx

(i

x 00001060000 1 xx xx

[ START] TRACEx OOp~l

060000 0 0 XX XX x O@ppl

‘EQREsTART ’OFF’ \ \\

RETURN OFSSYNASSERTIDN OF MSYN

TRACE[ALL STATESI

Figure 7-50. Trace Specification givirw exampleof Activity at 60000(8)

state and timing traces. The first problem, a time outproblem, could also have been resolved using state flowwith the HP 1610 Analyzer. The 10 MHz output ofthe 1610 is used to clock data into the analyzer andthe Format Specification of Figure 7-49 is set. Variablesto be traced include the address (in base eight) underlabel A, and seven control lines (in base two) as shownin Table 7-22. The trace specification menu (Figure7-50) is set to follow the sequence that should occurbeginning with address 60000 (8) on the address bus,

7-38 ORIGINAL

GENERAL MAINTENANCE NAVSEASEOOO-OO-EIM-160 DIGITAL TROUBLESHOOTINGTECHNIQUES

L“

L

but when MSYN flag is set, the correct response onthe SSYN line does not occur, and the third term ofthe sequence of triggers is not satisfied, changing thetrace specifications, and placing an x, (ignore) in thesequence where SSYN originally appeared, and usingtime count, produces the trace shown in Table 7-23.On the third line of the trace, the last of the sequence

times, the relative time count is 21.3 microseconds.But this exceeds the 20 microseconds limit of the bus,and using the same logic that was used above againleads to the deduction that the one shot is too long.

Table 7-23. Trace List Displ

------------------------------------------TRACE LIST-------------------------

LABELBASE

SEQUENCESEQUENCE

START+01+02

+03+04+05+06+07

+08+09+10+11

+12+13+14+15+16+17

AOCT

060000060000060000060000000000000000000000000000000000000000000000000000000000000000000000002240002240002240002240002240

B cBIN BIN

o 01 00 00 00 00 00 00 10 10 10 10 10 10 00 00 00 01 01 01 1

TIME MSYN WASASSERTED BY CPU

7-1.11 SUMMARYThe real time anrdysis capabilities

of logic analyzers make them excellent tools fortroubleshooting minicomputers. Analysis is evenfurther simplified by adding the appropriate inter-faces for easier connections and preprocessed signals.Logic analyzers can be used with syneronous orasyneronous minicomputer architecture. Examplesshow the advantages of logic analyzers in trouble-shooting both state and timing problems in mini-computer systems.

aying Time Measurements

---------------------TRACE-COMPLETE---------------------------------------------

D EBIN BIN

00 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 11

FBIN

11110000000000011111

TIMEDEC[R L]

.3 u s21.3 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

.1 u s

ELECTRONICS INSTALLATION and MAINTENANCE BOOK (EIMB) Comment Sheet

TITLE: PUBLICATION NO.:Fo Id o n d o t t e d line on r e v e r s e s i d e , sfopl=, and m ai I to the NAVAL SEA SYSTEMS COM?VIAND

PROBLEM O QUESTION ❑ SUGGESTION a COMMENT D (check one)

SUBJECT:

a

NAME

RANK/RATEITITLE

MAILING ADDRESS

%9TELEPHONE (A UTOVON) ( C O M M E R C I A L )

(NO ABBREVIATIONS PLEASE)

FOR OFFICAL USE ONLY

Fold- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

DEPARTMENT OF THE NAVYNAVAL SEA SYSTEMS COMMANDWASHINGTON, D. C. POSTAOE ANO FEES PAID,

DEPARTMENT OF THE NAW- - - - - - - - - - - - - - - - - - DoO 316

OFFICIAL BUSINESS

COMMANDERNAVAL SEA SYSTEMS COMMANDSEA 05L313WASHINGTON, DC 20362

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ELECTRONICS INSTALLATION and MAINTENANCE BOOK (EIMB) Comment Sheet

TITLE: PUBLICATION NO.:Fo Id on dot ted l ine on reverse s i d e , staple, and m Oi I ~0 ~~e NAVAL SEA SYSTEMS COMMAND

PROBLEM a QUESTION ❑ SUGGESTION a COMMENT O (*eck one)

SUBJECT:

NAME

RANK/RATE/T/TLE

MAILING ADDRESS

TELEPHONE (A UTOVON) ( C O M M E R C I A L )

040 ABBREVl AT10P4~ P L E A S E )

FOR OFFICAL USE ONLY

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DEPARTMENT OF THE NAVYNAVAL SEA SYSTEMS COMMANDWASHINGTON, D. C. P06TME AND FEES PAID, o -*.

DEPARTMENT OF THE NAW- - - - - - - - - - - - - - - - - - DoO 316

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