saleem dmp printer 4

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PRINTER

DOT MATRIX PRINTER (DMP)

MATRIX: - Numbers or dots arranged in rows & columns in a sequential order in closed brackets.

Ex: - [:::] it is 2x3 matrix. 2Rows & 3Columns.

Characters are printed in form of matrix. So these printers are called dot matrix printers.

BIT MAP IMAGE

The upper-case 'A' shown on a 5x7 matrix.

The lower-case 'y' shown on a 5x8 matrix. The tail would

be lost on a 5x7 matrix.

The space allotted for a single character printing is 9x9 or 24x24.

For every letter it has left margin, right margin. Top margin will be coming for small letters and bottom margin will come for capital letters. The left over space after margin is7x5 and letter will be printed in that area only.

SPEEDThe speed of DMP is measured in CPS (characters per second). Speed varies from 50cps to 500cps.

QUALITY:The image quality depends upon the spacing of pins in the print head. It is measured in CPI (characters per inch). Ex:- 10cpi(default), 12cpi, 15cpi.

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LPI: - LINES PER INCH 6lpi,(default), 8lpi,10lpi.

CLASSIFICATION: - types of DMPsPrint head’s are 4types 7, 9, 18 & 24 pin print heads

9 &24 pin PH is being used now mostly.

SIZE: - 80& 136 columns printers 8.1/2 & 13.2inchs. 40 columns are retail printers. Default paper size pc is 11`` we have to set it to 12`` for 80column paper.

Fonts:-Font is style of characters. Printers support normally draft, roman & Sanserif as default font.

Papers:- Cut sheets like A4 & b4 & Continues paper like 80 & 136colomuns.

MEDIA:- Ribbon is used as media in DMP`s. ribbon is an ink filled fabric. It houses in a cartridge. So it is called as ribbon cartridge. It is of many types each printer uses its own size and shape. It is 2types

1) Low density: it is used in 9pin printers. Length is 10mts.

2) High density: it is used in 24pin printers. Length is 15mts.

Manufactures:- WIPRO/WEP peripherals, Epson, TVSe

Identification of models

WIPRO/WEP

1) 9pin 80colomuns

a) LX 240

b) LX540

c) LX540+DX

d) LX 700

e) LX 700DX

f) LX 800

g) WEP 800DX

2) 9PIN 136COLOMUNS

a) EX 1050+

b) EX200

c) EX200+DX

d) EX 300

e) EX330+

f) EX330+DX

g) EX 5400

3) 24PIN 80COLOMUNS

a) LQ 540

b) LQ540DX

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4) 24PIN 136COLOMUNS

a) LQ 1050+

b) LQ 1050+DX

c) LQ 1050+DXGOLD

d) LQ DSI 5235

e) LQ5400

f) HQ1020

g) HQ 1030+

h) HQ 1040+

i) HQ 1070+

EPSON

1) 9PIN 80COLOMUNS

a) LX 300

b) LX300+

2) 9pin 136colomun

a) EX 1000

b) EX 1050+

c) FX1170

d) FX1180

e) FX2100

f) FX2700

3) 24PIN 80COLOMUNS

a) LQ 300

b) LQ 300+

4) 24PIN 136COLOMUNS

a) LQ 1050+

b) LQ 1070+

c) LQ 1080+

d) LQ 1180+

e) LQ 2180+

f) LQ 2780+

TVSE

TVSE 9PIN PRINTERS 80COLOUMN

1) Pro X 900

2) MSP 140 star

3) MSP 240 Classic Plus

4) HD 250 GOLD

5) MSP 240 Star

6) MSP 250 Star

TVSE 9PIN PRINTERS 136COLOUMN

1) MSP 245 Star

2) MSP 255

3) MSP 255 Marathon

4) MSP 245

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5) HD 245 GOLD

6) HD 755

7) HD 955

24PIN 80COLOMUNS PRINTERS

1) MSP 450 Champion

2) MSP 430

24PIN 136COLOMUNS PRINTERS

1) MSP 355

2) MSP 355Marthon

3) MSP 455 XLC

4) HD 745

5) HD 945

6) MSP 345 Star

BASIC PARTS OF PRINTER MECHANISUM

LOGIC CARD

SMPS

MECHANISUM SECTIONS CARRIAGE

SECTION

PAPER FEED SECTION

PRINT HEAD SECTION

MOTORS SECTION

SENSORS SECTION

CHECKING OF PRINTHEADSPrint heads are of 2 types 9pin & 24pin

9PIN PH 9pin 12conductor

9pin 14conductor

12conductor PH: - check on PCB side

1 6

4



7 12

9 Phases 3commons

From the common points to phases all should show same resistance.

14conductor PH: - check on PCB side

1 1 7

814

From the common points to phases all should show same resistance.

Commons phases 10 & 11 are thermister points.

1 2, 3, 8.

4 5, 6, 9

7 12, 13, 14

24PIN PRINTHEADS

Print heads are of 2types Double PCB Single PCB

Double PCB PH checking: - 24phases + 6commons + 2thermister = 32conductor (15c + 17c).

15Conductor: -commons phases 17Conductor: - commonsphases

6 1, 2,5,10 71,3,4,6

7 4, 9, 12, 14 85,11,12,17

8 3,11,13,15 92,10,13,14

15 & 16 points are thermister points in 17conductor.

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15conductor 17coductor

Single PCB PH checking: - 1

17 1

16 2

15 1

14 2

Single PCB PH checking: - 2

14 2

15 1

16 2

17 1

PRINTHEAD MECHANISUM & FIRING

As the printer head moves in horizontal direction, the print head controller sends electrical signals which forces the appropriate wires to strike against the inked ribbon, making dots on the paper and forming the desired

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characters. The most commonly used printer heads has 9 print wires in one column (9-pin print heads) or 24 print wires in two columns (24-pin print heads), for better print quality.

MOTORS

Motor is device which converts electrical energy in to mechanical energy (rotations).

There 2motors in printer

1)Hybrid Stepper Motor

2)Permanent Magnet Motor

Stepper motor winding output

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Stepper motor wiring diagrams.

Checking of CR motor & PF motor’s:-

5wire motors: - l l l l l 6wire motors: --

Commons phases commons phases

1 2, 3, 4, 5 2 – 1, 3 5 - 4, 6

3 1, 2, 4, 5 5 – 1, 2 6 – 3, 4

5 1, 2, 3, 4 3 – 1, 2 4 – 5, 6

SENSORS

Sensors are of 2 types1) Mechanical sensors

2) Optical sensors

Depending up on position of the sensor and working function they

I – Mechanical sensors

1) Paper end sensor 2) Multi part sensor 3) Tractor friction sensor

II – Optical sensors

1) Home position sensor

PAPER END SENSOR: - no paper condition (default) copper plates are shorted. I.e. it sends low signal to IC. Printer displays paper out LED in the control panel.

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If paper is inserted it sends high signal to IC.

MULTI PART SENSOR: - it senses the gap between PH and platen roller. When we insert single paper it sends low signal to IC. When we insert multiple papers it sends high signal to IC. At time it print head fires pins with more force as print quality should be same on first and last paper.

FRICTION /TRACTOR SENSOR: - This sensor is used to sense the path of the paper which we have chosen to load the paper either friction path or tractor path.

HOME POSITION SENSOR: - it is located at left side of the printer it sense the carriage block as it moves from left to right and right to left side o the printer.

MECHANICAL SENSORS : -

Signal in 2ways low signal & high signal 0 & 1

LOGIC CARDLOGIC CARD: - LC is PCB where all printer mechanism works with the help of electronic components. PCB are used to mechanically support and electronic components using conductive pathways or tracks etched from copper sheets laminated onto a non-conductive –substrate.

Logic card has to generate the required signals for running the stepper motors, accept the signals from the sensors for status information and act on it, generates required signals to the print head which prints the data on the ribbon which in turn hits the paper to form an impression.

Different section of LOGIC CARD

3) Logic section

4) Driving section

5) Interface section

6) Control panel

LOGIC SECTION:-

BIOS: - Basic In put out put System

PROM: - it stores the actual firmware of the printer and character generation information. Ex: - M27C512

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EPROM: - Erasable programmable read only memory.

In this type of ROMs we can delete the data and insert new data. But we can’t edit or add the data into it. We can delete the data with the help of ultra violet rays passing through the optical opening.

EEPROM: - (E2PROM) Electrically Erasable Programmable read only memory. In this type of ROMs we can delete the data and insert new data, edit the data and add the data.

CPU (OR) PROCESSER: - The CPU executes the instruction stored in the EPROM. It has powerful instructions set and control logic. The address bus of the CPU is decoded to select various devices like memory, interface and other chips. CPU make commonly used are NEC, Citizen, Toshiba, W so on. For ex: - uP78C10AGQ, uPD65682GF, uPD1900. in Wipro: - Varuna centum, Chriag SMD`s are used.

There are 2 types of processors in L/C.

Main CPU & CO CPU

64pin main CPU dip model

64pin SMD model

100pin SMD model

Co-CPU 80pin SMD model

100pin SMD model

RAMS: - Random Access Memory

Rams are used for storing data which comes from PC as a buffer for temporary purpose and working area of CPU while working. 2types of rams 1) Main rams & 2) Buffer rams.

CRYSTAL: - we can denote by X, Y, CR, OSC. Symbol

FUNCTION: - crystals are used for generating clock frequency. Which are 2types?

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1) Steel body 2) ceramic

DRIVING SECTION

1) Carriage motor driving section

2) PF motor driving section (paper feed)

3) PRINT HEAD driving section

CARRIAGE MOTOR DRIVING SECTION

Cr motor moves the CR block from left to right & right to left with the help of timing belt. PH will be moved according to data being printed by PH step by step. As we turn on the printer CR block should move to near the HOME POSITION sensor, if not then printer will not initialize.

PF MOTOR DRIVING SECTION

PF motor is used for loading and ejecting paper as we insert and feed the paper line by line according to data being printed.

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CPU

VARUNA CENTUM

S

L

A

7

0

2

6

CR MOTOR DRIVING CIRCUT



PRINT HEAD DRIVING SECTION:PH pins will be fired according to the data being printed.

10 Pin Transistor Packs

UPA1436AH this pack is used for print head driving and paper feed motor driving purpose in all WEP and EPSON printers.

12pin Transistor Packs

SLA4301/4301 is used for print head driving purpose in TVSE 9pin printers only.

16pin Transistor Packs

SDC02/03/04 this pack is used for paper feed motor driving purpose in TVSE printers only.

SDH02/03/04 this pack is used for carriage motor driving purpose in TVSE printers only.

M5248P, M5286P this pack is used for print head driving purpose in 24pin TVSE printers only.

18pin transistor pack/IC

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This pack is used for CR motor driving purpose in all makes of printers.

RESISTOR PACKS

2types serial packs parallel packs

INTERFACE

Interface cables are used for connecting printer with computer and print the required data. Types of interfaces

1) serial interface

2) Parallel interface

3) Network cable

4) USB cable

Type A Type B

CONTROL PANEL

CP is used for controlling and adjusting settings of the printer as per our requirements.

POWER LED: - This led indicates when printer is powered on.

DATA LED: - it indicates when printer receives data for printing from computer.

READY LED: - it indicates when printer is ready for printing when printer is turned on and paper is loaded for printing.

ONLINE LED: - it is used for indicating when printer online/offline. When printer is in online it prints the data. When it is in offline doesn’t print the data.

ONLINE LED &SWITCH : - When printer is printing the data, to pause the printing press the switch. To continue the printing from the same point again

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press the switch, it starts the printing from the same point where it has stopped printing.

FORM FEED SWITCH (FF):- when we have loaded paper after printer is turned on to micro feed the paper in forward bias press the switch. To go to next page, keep the printer in offline and press the switch.

LINE FEED SWITCH (LF):- when online led is blinking to reverse micro feed the paper press the switch. When online led is off if you press the switch paper will be feed line by line.

LOAD/EJECT SWITCH: - when printer is in tractor mode to load/eject the paper press the switch.

FONT LED`S & SWITCH: - LED’s indicate the type of font which we have chosen. Switch is used for selecting required font. Ex: - draft, roman…

PITCH LED’S & SWITCH: - LED’s are used for indicating selected CPI (characters per inch) 10CPI, 12CPI, 15CPI, PS (page select).

TROUBLESHOOTING OF DMP

No power condition:-

Check in put voltage and power cables (230VAC).

Check power supply for any damages.

Check PS out put voltages. (+5v, gnd, +/-12v, +24/27/30/35/40VDC)

Check logic card for any damages.

Printer not initializing : -

Check carriage block is moving freely or not, form left to right and right to left.

Check carriage shafts bending or rust.

Check timing belt damage.

Check carriage motor damage.

Check PS out put voltages coming correctly or not.

Abnormal feed of ribbon:-

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Check ribbon mask for damage.

Check ribbon mask holder for any damage.

Check ribbon cartridge.

Check ribbon driving assembly, if not rotating correctly in anti clock wise direction.

Check belt driven pulley physical damage.

Dot missing in the printing:-

Check print head pin’s & coils.

Check print head cables for cut & damage.

Check ribbon mask damage.

Check ribbon

Check print head driving section in logic card. (Circuit & components)

Abnormal feed of paper:-

Check paper feed gear (teeth damage).

Check paper feed motor damage.

Check platen roller damage.

Check paper path for any object struck in the way.

Check tractor gear.

Check sprockets in tractor unit.

Paper not loading:-

Check paper end sensor.

Check paper path.

Check paper feed gear.

Check paper feed motor.

Check PF motor driving section circuit.

Printing is dull one side of the paper:-

Check the head gap. (Gap between PH & platen roller)

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Check the CR shafts if any bending.

Check the carriage lock.

Printer not detecting:-

Check interface cables for any damage.

Check interface connectors any damage.

Check printer drivers mismatch.

Check components near by connectors.

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saleem dmp printer 4

Documents

sends low signal

sends high signal

home position sensor

pin print heads

check paper path

print head

logic card

control panel