imac20 early mid2009 technician guide

8/18/2019 IMac20 Early Mid2009 Technician Guide

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Apple Technician Guide

iMac (20-inch, Early/Mid 2009)iMac (20-inch, Early 2009), iMac (20-inch, Mid 2009)Updated: 2010-11-24


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Apple Inc.

© 2009-2010 Apple Inc. All rights reserved.

Under the copyright laws, this document may not be copied, in whole or in part, without thewritten consent of Apple.

Every eort has been made to ensure that the information in this document is accurate. Apple

is not responsible for printing or clerical errors.

Apple1 Innite LoopCupertino, CA 95014-2084USA+ 1 408 996 1010www.apple.com

Apple, the Apple logo, Mac, and Macintosh are trademarks of Apple Inc., registered in the U.S.and other countries.


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iMac (20-inch, Early/Mid 2009)

About This Guide

Updates 8Updated 24 November 2010 8Updated 1 May 2009 8Updated 28 April 2009 8Introduced 3 March 2009 9

Feedback 9

Basics

Overview 11Product Features 11Dierences Between Models 11Product Conguration 12Serial Number Location 12

Troubleshooting

General Troubleshooting 14Update System Software & Firmware 14

Troubleshooting Theory 14Hardware vs. Software 14

Apple Hardware Test 14Apple Service Diagnostic 15Common Reset Procedures 15

Power On Self Test (POST) 15Starting Up in Safe Mode 15Resetting Parameter RAM (PRAM) 16Resetting the System Management Controller (SMC) 16

Diagnostic LEDs 17Sensor and Fan Connector Locations 18Block Diagram 19

Symptom Charts 20Startup and Power 20No Power, Dead Unit 20Won’t Start Up 22Intermittent Shutdown 24Kernel Panic, System Crashes 26No Video 28Corrupted Video 29Burnt Smell/Odor 31Uncategorized Symptoms 32


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Display 33Backlight Issue/No Backlight 33Incorrect/Missing Colors 38Distorted/Blurred Image 39Pixel Anomalies 41Vertical/Horizontal Lines 42Non-Uniform Brightness 44Cosmetic Defects 45Uncategorized Symptoms 45

Mass Storage 46Hard Drive Not Recognized 46Hard Drive Read/Write Error 48Hard Drive Noisy 49Optical Drive Not Recognized 51Optical Drive Won’t Accept/Eject Media 52Optical Drive Read/Write Error 54

Optical Drive Not Performing to Specications 55Optical Drive Noisy 56Uncategorized Symptoms 57

Communications 58AirPort/Bluetooth Issues 58AirPort Card Kernel Panic 60Ethernet Port/Device Issue 61Wireless Input Device Doesn’t Pair 62Wireless Input Device Loses Connection 64Uncategorized Symptoms 66

Input/Output Devices 67

Apple Remote Inoperable 67Audio: Microphone 68Audio: Built-in Speakers Have Distorted Sound 70Audio: Built-in Speakers Have No Audio 71Camera Issues 73FireWire Devices Not Recognized 74USB Devices Not Recognized 76Wired Keyboard Does Not Function Properly 78Keyboard: Specic Keys Do Not Respond 80Wired Keyboard/Mouse Not Recognized 80Uncategorized Symptoms 82

Mechanical 83Noise/Hum/Vibration 83Fan Failures / Thermal Issues 86Stand/Hinge Issues 87Physical Damage 87Uncategorized Symptoms 88


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Take Apart

General Information 90Opening the Unit 90Required Tools 90

Required Special Tools for Glass Panel 91Cleaning Tools Starter Kit 91

Cleaning & Handling the Glass Panel 92Do’s and Don’ts 92Handling a Broken Glass Panel 92

How to Remove a Broken Glass Panel 93Safety 97Logic Board Handling 98Reassembly Steps 99Images in This Guide 99Screw Sizes 99

Access Door 100

Memory 101

Glass Panel 103Removal 104Reassembly 105

Front Bezel 109

Camera 112

Battery 114

IR (Infrared) Board 116AirPort Extreme Card 118

Bluetooth Board 120

LCD Panel 122

LVDS Cable 126

Hard Drive 128

Hard Drive Sensor Cable 132

Optical Drive 134

Optical Drive Sensor Cable 137

Optical Drive Fan 139

Optical Drive Data Cable 141

Inverter 143

Power Supply 145


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Left Speaker 148

Ambient Temp Sensor Cable 150

CPU Fan 152

Right Speaker 154

Audio Board 156Logic Board 159

Removal 160Reassembly 161Handling Logic Boards 163

Hard Drive Fan 164

Hard Drive Data Cable 166

Mechanism Cover 167

Stand 168Mechanism 170

Chassis 172

Cable, DC, Power Supply/SATA/Inverter 175Removal 176Reassembly 178

Camera Cable 181

Microphone Cable 183Rear Housing 185

Views

Exploded Views 187iMac (20-inch, Early 2009), Part 1 187iMac (20-inch, Early 2009), Part 2 188iMac (20-inch, Mid 2009), Part 1 189iMac (20-inch, Mid 2009), Part 2 190

Screw Chart 191

Internal Views 193

I/O Ports 195


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About This GuideiMac (20-inch, Early/Mid 2009)


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iMac (20-inch, Early/Mid 2009) — Updates 82010-11-24

Updates

Updated 24 November 2010

Troubleshooting:• General: Updated information and links for Updating System Software & Firmware,

Troubleshooting Theory, and Common Reset Procedures.• Startup and Power: No Power, Dead Unit: Step 6: Yes: Changed action to “Go to step 7.”• Startup and Power: Intermittent Shutdown: Step 1: Updated information about which

console log to check for OS 10.6 vs. OS 10.5 and earlier.

Take Apart:• General:

• Updated “Required Tools” and removed commercial screen cleaning products;• Rewrote “Handling a Broken Glass Panel”;• Consolidated information about ESD Safety.

• Access Door: Modied “First Steps”.• Glass Panel: Modied “First Steps” and cleaning procedures; microber cloth should only

be dampened with water (rather than isopropyl alcohol or commerical screen cleaningproducts).

• Camera: Changed tool needed from T8 to T10 screwdriver.• Logic Board and Audio Board: Added note “If replacing logic board, be sure to leave audio

board attached and return it with the old logic board.”

Views:• Exploded Views:• Removed iMac (20-inch, Early 2009) logic board part #661-4984, which is now

substituted with part #661-5136.• Added iMac (20-inch, Mid 2009) 2.26 GHz logic board part #661-5514.

Updated 1 May 2009

Views:• Exploded Views: Corrected rear housing information for Mid 2009 model.

Updated 28 April 2009Basics:• Added section about dierences between Early 2009 and Mid 2009 models.

Troubleshooting:• General Troubleshooting: Added sections about Apple Hardware Test and Apple Service

Diagnostic, how to determine which version to use.


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iMac (20-inch, Early/Mid 2009) — Feedback 92010-11-24

• Block Diagram: Added note that Mid 2009 model does not have IR or Bluetooth.

Take Apart:• Front Bezel: Added reassembly note to install bottom of bezel rst.• Camera Board: Corrected screw size and part number.• IR Board: Added note that Mid 2009 model does not have an IR Board.

• Bluetooth Board: Added note that Mid 2009 model does not have a Bluetooth Board.• Optical Drive: Added reassembly note to avoid trapped inverter cables.• Hard Drive Sensor Cable, Optical Drive Sensor Cable, Hard Drive Fan: Added details about

connector pin sizes.• Logic Board: Added note that Mid 2009 model does not have IR or Bluetooth boards. Added

note to route camera cable over, not under, the logic board. Removed note to transfer blackplastic airdam from old board to new board, as it should be included with new board.

Views:• Exploded Views: Added 1 logic board part number for Early 2009 model. Added new

exploded views for Mid 2009 model.

• Screw Chart: Corrected camera screw size and part number.

Introduced 3 March 2009

Feedback

We want your feedback to help improve this and future Technician Guides!

Please email any comments to: [email protected]

mailto:smfeedback6%40apple.com?subject=iMac%20%2820-inch%2C%20Early/Mid%202009%29mailto:smfeedback6%40apple.com?subject=iMac%20%2820-inch%2C%20Early/Mid%202009%29


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BasicsiMac (20-inch, Early/Mid 2009)


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iMac (20-inch, Early/Mid 2009) Basics — Overview 112010-11-24

Overview

Product Features

The iMac (20-inch, Early 2009) and iMac (20-inch, Mid 2009) computers have the same overalllook as the previous generation aluminum iMac. Distinguishing exterior features are MiniDisplayPort (instead of mini DVI port) and 4 USB ports (instead of 3) on the rear, and a taperedfront edge on the stand.

New features:• Increased processor speed: 2.66GHz• Mini DisplayPort• 4 USB 2.0 ports• Increased RAM capacity: 2GB min, 8GB max• Increased hard drive capacity in Early 2009 model: 320/640/1TB

Dierences Between Models

The iMac (20-inch, Early 2009) and iMac (20-inch, Mid 2009) computers are very similar. Thedierences are that the Mid 2009 model does not have IR (Infrared) or Bluetooth, and has asmaller capacity hard drive (160GB).


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iMac (20-inch, Early/Mid 2009) Basics — Overview 122010-11-24

Product Conguration

To conrm the conguration from the Apple menu, choose About This Mac. The processorlisting will show the speed of the processor followed by the processor type. The following table

shows the conguration at introduction:

Feature Specication

Processor 2.66 GHz Intel Core 2 Duo6MB shared L2 cache, 1066MHz frontside bus

Memory 2GB (2 x 1GB) 1066MHz DDR3 (optional 4GB, 8GB CTO)

Hard Drive Early 2009: 320GB Serial ATA 7200-rpm (optional 640GB, 1TB)Mid 2009: 160GB Serial ATA 7200-rpm

Optical Drive 8x SATA SuperDrive

Display 20-inch, 1680x1050 resolution, 800:1 contrast ratio, 290 cd/m brightness,160-degree viewing angle, glossy

Graphics NVIDIA GeForce 9400M with 256MB shared memory

Wireless AirPort Extreme 802.11a/b/g/n, Bluetooth 2.1 + EDR (only in Early 2009)

Input Devices wired keyboard, wired mouse, no remote, no modem

I/O Gigabit Ethernet, (4) USB 2.0, (1) FireWire 800

Audio I/O iPhone headset connector, microphone, stereo speakers, combo digital in

Video I/O Mini-DisplayPort (HDCP, dual-link, dual display; simultaneously supportsfull native resolution on built-in display and up to 2560x1600 on anexternal 30-inch display), iSight camera

Power Supply 180W universal

Serial Number Location The iMac (20-inch, Early/Mid 2009)’s serial number is located on the base of the stand. Whenreplacing a stand, transfer the serial number to the new stand.


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TroubleshootingiMac (20-inch, Early/Mid 2009)


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iMac (20-inch, Early/Mid 2009) Troubleshooting — General Troubleshooting 142010-11-24

General Troubleshooting

Update System Software & FirmwareImportant: Ensure the correct version Mac OS X and latest software and rmware updates havebeen applied before you begin troubleshooting. Computers sometimes exhibit symptoms thatindicate the wrong Mac OS X system software is installed.

Firmware is the name given to software that is written into memory circuits such as ashmemory, that will hold the software code indenitely, even when power is removed fromthe hardware. Firmware on Intel Mac computers is designed to be updated if necessary byrunning the Mac OS X Software Update check (available in the Apple menu) while computer isconnected to the Internet. For more information about rmware updates, refer to:

kBase #HT1557: About rmware updates for Intel-based Macs kBase #HT1237: EFI and SMC rmware updates for Intel-based Macs

Troubleshooting Theory

For general information on troubleshooting theory, go to GSX and nd the Service Trainingcourse menu link. From there you can access the Troubleshooting Theory self-paced course.

Hardware vs. Software

For information on how to isolate a hardware issue from a software issue, refer to:

kBase #TS1388: Isolating issues in Mac OS XFor information on how to troubleshoot a software issue, refer to:kBase #HT1199: Mac OS X: How to troubleshoot a software issue kBase #TS1394: Mac OS X: Troubleshooting installation and software updateskBase #HT2956: Troubleshooting Mac OS X installation from CD or DVD

Apple Hardware Test

There are two versions of Apple Hardware Test (AHT) for the iMac (20-inch, Early 2009). Toidentify which version of AHT to use, check the third, fourth, and fth digits in the system serialnumber. See examples below.• Apple Hardware Test 3A156 to be used on systems with the third, fourth, and fth serial

number digits below 913. Example: Serial number W 8 9 1 0 S M R D W K • Apple Hardware Test 3A168 to be used on systems with the third, fourth, and fth serial

number digits equal to or higher than 913. Example: Serial number W 8 9 1 3 8 M T 0 T F

The iMac (20-inch, Mid 2009) uses Apple Hardware Test 3A168.

http://support.apple.com/kb/HT1557http://support.apple.com/kb/HT1237http://support.apple.com/kb/TS1388http://support.apple.com/kb/HT1199http://support.apple.com/kb/TS1394http://support.apple.com/kb/HT2956http://support.apple.com/kb/HT2956http://support.apple.com/kb/TS1394http://support.apple.com/kb/HT1199http://support.apple.com/kb/TS1388http://support.apple.com/kb/HT1237http://support.apple.com/kb/HT1557


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Apple Service Diagnostic

The correct version for all iMac (20-inch, Early/Mid 2009) is Apple Service Diagnostic 3S131.

Common Reset Procedures

Power On Self Test (POST)

Intel-based Mac computers such as the iMac rely on a combination of tones and blinking LEDsto display Power On Self Test (POST) error codes.• If the computer detects out-of-specication or no SDRAM or the RAM installed does not

meet the appropriate specications, the screen will remain black but the computer willbeep. This error condition may be due to physically damaged RAM, installing the incorrecttype of RAM, or not having RAM installed.

• Some RAM may appear to pass the Power-On-Self-Test (POST) but still cannot be used bythe operating system. In this case, the computer will display a gray screen, sound three

tones and repeat the tones until the computer is turned o.• The solution to both of these situations is to rst re-seat the memory and test the computer

again. If the memory fails the POST test again, try memory that has been veried to workcorrectly on another system (i.e., “known-good”) or order new memory.

For more information, refer to:kBase #HT2538: iMac (Mid 2007) and later models: About new startup tones

Starting Up in Safe Mode

A Safe Boot is a special way to start Mac OS X when troubleshooting. Starting up into Safe

Mode does several things that can help resolve software or directory issues that may exist onthe startup volume. To start up in Safe Mode:

1. Make sure computer is shut down.

2. Press power button.

3. Immediately after you hear the startup tone, press and hold Shift key.Note: The Shift key should be held as soon as possible after startup tone but not before.

4. Release Shift key when you see the screen with the gray Apple and progress indicator(looks like a spinning gear). Note that booting into Safe Mode will take longer than a normalstartup. During startup, the words ”Safe Boot” appear on the Mac OS X startup screen and a

gray progress bar is displayed on bottom of window (since Mac OS X 10.6).5. To leave Safe Mode, restart computer normally, without holding down any keys during

startup.

For more information, refer to:kBase #HT1564: Mac OS X: What is Safe Boot, Safe Mode? kBase #TS1884: Safe Boot takes longer than normal startup

http://support.apple.com/kb/HT2538http://support.apple.com/kb/HT1564http://support.apple.com/kb/TS1884http://support.apple.com/kb/TS1884http://support.apple.com/kb/HT1564http://support.apple.com/kb/HT2538


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Resetting Parameter RAM (PRAM)

PRAM stores certain system and device settings in a location that Mac OS X can access quickly.Exactly which settings are stored in the computer’s PRAM varies depending on the type ofcomputer as well as the types of devices and drives connected. To reset PRAM:

1. Shut down the computer.2. Locate the following keys on keyboard: Command, Option, P, and R. You will need to hold

these keys down simultaneously in Step 4.Note: If the keyboard does not have an Option key, use the Alt key instead.

3. Press power button.

4. Immediately press and hold Command-Option-P-R keys.Important: You must press this key combination before the gray screen appears.

5. Hold down keys until the computer restarts, and you hear the startup chime a second time.

6. Release keys.

For more information, refer to:kBase #HT1242: Mac OS X: What’s stored in PRAMkBase #HT1379: Resetting your Mac’s PRAM and NVRAM

Resetting the System Management Controller (SMC)

The System Management Controller (SMC) is a chip on logic board that controls all powerfunctions. If computer is experiencing any power issue, such as not starting up, not displayingvideo, sleep issues, or fan noise issues, resetting SMC may resolve it. To reset SMC on an iMac:

7. From Apple menu, choose Shut Down (or if the computer is not responding, hold powerbutton for approximately ten seconds until it powers o).

8. Unplug all cables from computer, including power cord.

9. Press and hold the power button for 5 seconds.

10. Release the power button.

11. Attach the computer’s power cable, making sure power button is not being pressed.Note: If you press the power button while inserting the power cord, the iMac will enter amode in which the fans run at full speed. For more information, refer to:kBase #TS1433: iMac: Fans run at full speed after computer turns on

12. Press the power button to turn on the computer.For more information, refer to:kBase #HT1543: Intel-based iMacs: Resetting the System Management Controller (SMC)

http://support.apple.com/kb/HT1242http://support.apple.com/kb/HT1379http://support.apple.com/kb/TS1433http://support.apple.com/kb/TS1433http://support.apple.com/kb/HT1379http://support.apple.com/kb/HT1242


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Diagnostic LEDs

The iMac has built-in diagnostic LEDs on the main logic board that can help you totroubleshoot the computer. The LEDs are located to the right of the battery (see photo below).

LED #1

Indicates the trickle voltage from the power supply has been detected by the logic board. This LED will remain ON whenever the iMac is connected to a working AC power source. The LED will remain on even when the computer has been shut down or put to sleep. TheLED will turn o only if the AC power source is disconnected or the power supply is faulty.

LED #2

Indicates the main logic board has detected proper power from the power supply whenthe computer is turned on. This LED will be ON when the computer is turned on and thepower supply is working correctly.

LED #3

Note: This LED is not used on systems that have integrated graphics, which includes allcongurations of the iMac (20-inch, Early/Mid 2009).

LED #4

Indicates the computer and the LCD display panel are communicating. This LED will be ONwhen the computer is turned on and video signal is being generated. If the LED is ON andthere is no image on the LCD display panel, the LCD display panel or inverter might beinstalled incorrectly or need replacement.


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Sensor and Fan Connector Locations

Ambient temp sensor and fan connector locations are shown below. Ensure cables arecorrectly routed and the sensors and fans are properly connected. If a sensor or fan is faulty ornot connected, Apple Hardware Test will generate an error code.


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Block Diagram

Refer to this diagram to see how modules are interrelated.Note: The iMac (20-inch, Mid 2009) does not have IR or Bluetooth.

MLB

Ambient

Temperature

Sensor

802.11n

Antenna

Bluetooth

Antenna

Display

Temperature

Sensor

AC/DCTemperature

Sensor

Hard Drive

Temperature

Sensor

Optical Drive

HD Fan

ODD Fan

CPU Fan SO-DIMM SO-DIMM

SpeakerSpeaker

IR Sensor

Audio Board

Power Button

AC Inlet

Camera Microphone

Inverter

Temperature

Sensor

PCIe x1

DDR3-1066 DDR3-1066

USB 2.0USB 2.0

USB 2.0 SATA II

SATA II

12V in 20”

Antenna


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iMac (20-inch, Early/Mid 2009) Symptom Charts — Startup and Power 202010-11-24

Symptom ChartsFollow the steps in the order indicated below. If an action resolves the issue, retest the systemto verify.

Note: A compilation of Quick Check tables is available at:http://service.info.apple.com/QRS/en/quickreference.pdf

Startup and Power

No Power, Dead Unit

Unlikely cause: speakers

Quick Check

Symptoms Quick Check

No Power, Dead Unit• No power• No fan spin• No startup chime• No image on external display

• No hard drive or optical driveactivity• Caps Lock LED on wired

keyboard doesn’t light whenpressed.

1. Verify power source.

2. Verify power cable.

3. Listen closely for signs of activity from systemincluding: rotating fans, hard drive or optical driveactivity, startup chime, etc.

Deep Dive

Check Result Action Code

1. Power ON system. Verify if

there is any indication that thesystem has powered up (fanrotation, hard drive or opticaldrive noise, backlight turns on).

Yes The symptom is powering up.

Jump to Won’t Start Up.No Go to step 2.

http://xkcd.com/518/http://service.info.apple.com/QRS/en/quickreference.pdfhttp://service.info.apple.com/QRS/en/quickreference.pdfhttp://xkcd.com/518/


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2. Remove front bezel and locatediagnostic LED’s on logic board.Plug power cord into system.Verify whether diagnostic LED#1 turns ON.

Yes Trickle voltage being suppliedby power supply. Go to step 3.

No Replace power supply.

3. Press power button whilemonitoring diagnostic LED’s.Does diagnostic LED #2 turnON and remain ON afterpressing the power button?

Yes Power supply functioning andlogic board detects supplyvoltages. Jump to Won’t StartUp.

No Go to step 5.

4. Disconnect power then removepower supply and carefullyinspect AC inlet and DC outputconnectors and cables fordamage or poor connections.Were any problems identied?

Yes Replace damaged part. P16

No Go to step 5.

5. Inspect power button andverify that it is properlyconnected to the logic board.

Yes Visual inspection OK.Go to step 6.

No Reconnect power button.Replace rear housing (whichincludes power button) orlogic board if damage ispresent.

X14

6. Disconnect power buttonfrom logic board and verify

continuity between two pinswhen power button is pressed.

Yes Power button is functioningcorrectly. Go to step 7.

No Power button faulty. Replacerear housing which includespower button.

X16

7. Press power button and verifywhether system turns ON.

Yes Power supply is functioning.If system still does not boot

jump to Won’t Start Up.

No Replace power supply. Retest. P01

Note: If No Power symptom persists after all steps have been followed use Minimum

Conguration troubleshooting to proceed. Try disconnecting the hard drive, optical drive,AirPort, and Bluetooth modules to determine if one of them is preventing the power supplyfrom functioning.


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Won’t Start Up

Quick Check


Won’t Start Up• No startup chime.• Error tones during startup.• Grey screen with fan noise, or

other noise.• Will not progress beyond

Apple logo or spinning gear.

1. Isolate OS by starting up from original installmedia for the computer, the same make andmodel computer in Target Disk Mode, orcompatible known-good OS on an external drive.Both AirPort and Bluetooth services are availablewhen booted from the Install disk.

2. Reset SMC and PRAM to clear any stored,corrupted information.

3. Start up in Safe Mode by holding the shift keydown during startup to load only required kernelextensions and disable all startup and loginitems. See KBase article

http://support.apple.com/kb/HT15644. If system generates error tones there may be an

issue with the SDRAM. See KBase articlehttp://support.apple.com/kb/HT2341

5. Identifying when in the startup process thecomputer hangs can help isolate the issue.See KBase articlehttp://support.apple.com/kb/HT2674for information on the Macintosh startupsequence, error codes and symbols used.

Deep Dive


1. Boot the computer to AppleHardware Test on the InstallDVD. Does the computer bootup to this volume?

Yes Run the extended testsand proceed with results. IfAHT passes or boots with amemory error, go to step 2.

No Go to step 2.

2. Remove the installed SDRAM,

and test with known-goodSDRAM. Does the computerstartup properly now?

Yes SDRAM issue. Replace SDRAM.

Issue resolved.

X02

No Go to step 3.

http://support.apple.com/kb/HT1564http://support.apple.com/kb/HT2341http://support.apple.com/kb/HT2674http://support.apple.com/kb/HT2674http://support.apple.com/kb/HT2341http://support.apple.com/kb/HT1564


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3. Remove the coin battery onthe logic board, and leave outfor approximately 1 minute.

Then reinstall the battery. Thiswill reset the logic board. Doesthe computer startup properly

now?

Yes Issue resolved by logic boardreset. Measure DC voltageon the battery touching thebattery with the red probe,and grounding with the blackprobe. If voltage is 2.7v or less,

replace the battery. See KBasearticle http://support.apple.com/kb/HT3250 for detailson using a digital multi-meter.

No Go to step 4.

4. Remove AirPort card and test.Does the computer startupproperly now?

Yes Go to AirPort Card KernelPanic.

No Go to step 5.

5. Disconnect the hard drive SATA

cable and startup to the InstallDVD on the optical drive, oran external volume. Does thecomputer startup properlynow?

Yes Go to Hard Drive Not

Recognized.

No Go to step 6.

6. Disconnect the optical driveand test. Does the computerstart without kernel panic now?

Yes Go to Optical Drive NotRecognized.

No Replace logic board. M02

http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250http://support.apple.com/kb/HT3250


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Intermittent Shutdown

Quick Check


Intermittent Shutdown• Powers o during startup.• Powers o during desktop use.• Computer restarts

spontaneously.• Powers o when waking from

sleep.

1. Isolate OS by starting up from original Installmedia for the computer, the same modelcomputer in Target Disk Mode, or compatibleknown-good OS on an external drive. BothAirPort and Bluetooth services are available whenbooted from the Install disc.


3. Start up in Safe Mode by holding the shift keydown during startup to load only required kernelextensions and disable all startup and loginitems. See KBase article

http://support.apple.com/kb/HT15644. Open System Preferences > Energy Saver >

Schedule and make sure that a ‘Shut Down’ eventis not scheduled.

5. Make sure that power cord is securely attached tothe back of the computer, and is not hindered bya desk or other furniture.

6. Plug the computer directly into an AC outlet totest whether a surge protector, outlet strip, or UPSis causing the issue.

Deep Dive


1. Verify improper shutdown inConsole:- for Mac OS 10.5 or earlier, lookin system.log- for Mac OS 10.6, look in

/private/var/log/kernel.log

Filter the log for “shutdown

cause”. Entries of value “0” ora negative value indicate animproper shutdown.

Did you nd entries ofimproper shutdown?

Yes Determine if user causedimproper shutdown. Useknown-good AC power cordand AC outlet. Go to step 2.

No Revisit Quick Check examplesfor possible software issues.Check if user is running

other automating softwarethat may be shutting downsystem. Verify issue and jumpto appropriate symptomow. No repair needed undercurrent symptom ow.

http://support.apple.com/kb/HT1564http://support.apple.com/kb/HT1564


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2. With known-good AC powercord and AC outlet, does theunit continue to shutdown?

Yes Go to step 3.

No AC power cord/ outlet issue.Issue resolved.

X03

3. Disconnect the hard drive

power cable from the harddrive and start the machinefrom the Install DVD, the samemake and model computerin Target Disk Mode, orcompatible known-good OSon an external drive. Doesthe computer continue toshutdown?

Yes Go to step 4.

No Possible bad software or harddrive. Go to Hard Drive NotRecognized.

4. Inspect and reseat DC powercable and AC inlet connectionsto power supply and logic

board. Was damage observedon the cables or connectors.

Yes Replace damaged cable.Retest. Return to step 1 ifproblem continues.

X03

No Go to step 5.

5. Install known-good powersupply. Does system continueto restart or shutdown?

Yes Reinstall original powersupply. Replace logic board.Go to step 6.

No Power supply issue.Issue resolved.

P02

6. After logic board replacement.does the computer continue toshutdown?

Yes Use Minimum Congurationtroubleshooting to isolatefailed module.

No Logic board issue.Issue resolved.

M08


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Kernel Panic, System Crashes

Quick Check


Kernel Panic, System Crashes• Kernel panic on startup ordesktop use.

• System freeze during use.• System freeze upon wake from

sleep.

1. Isolate OS by starting up system from originalInstall media for the computer, the same makeand model computer in Target Disk Mode, orcompatible known-good OS on an external drive.Both AirPort and Bluetooth services are availablewhen booted from the Install disc.

2. Ensure that all software and rmware updates forthe computer have been installed.


4. Start up in Safe Mode by holding the shift keydown during startup to load only required kernelextensions and disable all startup and loginitems. See KBase articlehttp://support.apple.com/kb/HT1564

5. Check the panic.log, located /Library/Logs/Panicreporter, for information in the backtracethat may give clues about the kernel panic.

6. For more information on kernel panics refer toKBase articlehttp://support.apple.com/kb/HT1392

Deep DiveCheck Result Action Code

1. Boot the machine to AppleHardware Test on the InstallDVD. Does the computer bootup to this volume?

Yes Run the extended tests andproceed with results. If AHTpasses or boots with a kernelpanic, go to step 2.

No Go to step 2.

2. Remove all peripheral devicesincluding the keyboard and

mouse. Does computer startwithout kernel panic?

Yes Add peripheral devices one ata time until the kernel panic

repeats. Replace the devicecausing the issue.

No Go to step 3.

http://support.apple.com/kb/HT1564http://support.apple.com/kb/HT1392http://support.apple.com/kb/HT1392http://support.apple.com/kb/HT1564


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3. Use known-good SDRAM inthe system. Does the computerstart without kernel panic now?

Yes Install user’s SDRAM and test.If kernel panic repeats, replaceSDRAM. Verify that the correctSDRAM is being used.

X01

No Go to step 4.

4. Remove AirPort card andtest. Does the computer startwithout kernel panic now?

Yes Go to AirPort Card KernelPanic.

No Go to step 5.

5. Disconnect the hard drive SATAcable and startup to the InstallDVD on the optical drive, oran external volume. Does thecomputer start without kernelpanic now?

Yes Go to Hard Drive NotRecognized.

No Go to step 6.

6. Disconnect the camera/microphone cable. Does thecomputer start without kernelpanic now?

Yes Go to Camera Issues.

No Go to step 7.

7. Disconnect the audio boardand test. Does the computerstart without kernel panic now?

Yes Replace audio board. X99

No Go to step 8.

8. Disconnect the optical driveand test. Does the computerstart without kernel panic now?

Yes Go to Optical Drive NotRecognized.

No Replace logic board.


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No Video

Unlikely cause: hard drive, optical drive, speakers, camera, microphone

Quick Check

Symptoms Quick Check No Video• No image.• Backlight failure.

1. Check brightness setting.

2. For no-video issues, connect an externaldisplay to verify whether iMac video circuitry isfunctioning. If image appears on external displaygo to Backlight Issue/No Backlight.

3. Reset SMC.

Deep Dive


1. Verify boot chime present andfans running when systempowered ON. (Reset SMC andclear PRAM if necessary forproper boot up.)

Yes Power ON self test OK. Bootsequence started.Go to step 2.

No Go to Won’t Start Up.

2. Verify whether image is visibleon LCD panel.

Yes Video present. Verify systemfunctionality and return touser or jump to appropriatetroubleshooting ow.

No Go to step 3.

3. Connect supported externaldisplay. Verify whether imageappears on external displaywhen system is booted.

Yes External display detected bysystem. Video circuitry onlogic board functional. Go toBacklight Issue/No Backlight

No Go to step 4.

4. Remove glass panel and frontbezel. Do all three diagnosticLED’s turn ON shortly after thesystem is powered ON?

Yes Internal video circuitryfunctional andcommunicating with LCDpanel. Go to Backlight Issue/

No Backlight.

No Replace logic board. Retest. M03


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Corrupted Video

Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone

Quick Check

Symptoms Quick Check Corrupted Video• Text and graphics appear fuzzy• Image corrupted

1. Set System Preferences/Display LCD panel tonative resolution. Non-native resolutions areunable to produce optimal clarity.

2. Make sure all relevant software updates havebeen applied. Graphics driver updates may beincluded with software updates.

3. When the issue occurs take a screenshot of thedisplay (Command-Shift-3). View the screen shotle on another known-good computer. If theimage corruption can be seen in the screenshot

then the issue is with the video drivers, software,or video/logic board. If the issue cannot be seenin the screenshot then the LCD panel and LVDScable should be tested further.

4. Clean the outside surface of glass panel usingprovided cleaning cloth.

5. Boot from install DVD or another known-goodvolume to determine whether a potentialsoftware/driver issue exists.

Deep Dive


1. Boot from Install DVD andverify whether issue is stillvisible.

Yes Go to step 2.

No Issue likely caused bysoftware or driver issue.

Troubleshoot for softwareissues. Make sure all softwareupdates have been installed.

2. Verify whether issue is visibleon an external display attachedto the DisplayPort.

Yes Issue is NOT caused byinternal LCD panel.Go to step 3.

No Go to step 5.


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3. Remove logic board, inspectconnectors for damage orcorrosion then reinstall. Verifywhether issue still occurs.

Yes Replace logic board.Go to step 4.

M04

No Issue likely caused by poorconnection. Return computerto user.

M04

4. Verify whether issue is stillpresent with replacement logicboard installed.

Yes Return to step 1 and retest. X04

No Issue resolved withreplacement logic board.Return computer to user.

M04

5. Remove LVDS cable from LCDpanel and logic board andcarefully verify whether thereis damage to the cable orconnectors.

Yes Replace LVDS cable.

No Reinstall LVDS cable.Go to step 6.

6. Verify whether issue is stillvisible after reinstalling LVDScable.

Yes Replace LCD panel.Go to step 7.


M04

7. Verify whether issue is stillpresent with replacement LCDpanel installed.

Yes Return to step 1 and retest.

No Issue resolved withreplacement LCD panel.Return computer to user.

L04


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Burnt Smell/Odor

Unlikely cause: speakers, microphone, enclosure

Quick Check

Symptoms Quick Check Burnt Smell/Odor• Burning smell• Unusual odor

1. Verify source of smell/odor is emanating from thesystem.

2. If system is new refer to KBase articlehttp://support.apple.com/kb/TA22044 for information on new computer odors.

3. Disconnect all third-party devices and conrmwhether the odor is being generated by thedevice.

4. Inspect air intake and air outlets for obstructions. To prevent overheating make sure thereis sucient clearance to allow air to owunobstructed into and out of the system.

5. Verify whether system is functional.

Deep Dive


1. Verify whether the source ofthe odor can be identiedby visually inspecting each

module and its associatedcables for signs of burned ordamaged components, smokeresidue, burned traces, ormelted or damaged wiring,

Yes Replace aected module(s).Go to step 2

P08

No Unable to locate source ofodor. Go to step 3.

2. Disconnect all third-partydevices and cables. Power ONsystem and verify whethersmoke or strong odor returns.

Yes Power down systemimmediately. Go to step 3.

No System functions correctly.Verify system functionalitywith third-party devices andcables and return system

to user if problem has beenresolved. Consult third-partycompanies as needed forissues with those products.

http://support.apple.com/kb/TA22044http://support.apple.com/kb/TA22044


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3. Can the source of the odor belocated using nose?

Yes Replace aect module(s) andretest system.

P08

No Contact Apple for assistanceif you feel that there is apossible safety issue with thecomputer that has not beenresolved in the previous steps.

Uncategorized Symptoms

Quick Check



• Unable to locate appropriatesymptom code.

1. Make sure system is plugged into a known-good

outlet.2. Listen for boot chime, fan, optical drive, or hard

drive noise which indicates system is poweringup. If noise is heard, go to Won’t Start Up. If nonoise is heard go to No Power, Dead Unit.

3. Attempt to boot from Install DVD to isolatepossible software issues.

Deep Dive


1. Verify whether existingsymptom code applies to theissue reported by the user.

Yes Jump to appropriatesymptom code ow.

No Document reported failureand send feedback [email protected] stating that a suitablesymptom code wasn’t found.Provide as much detail aspossible.

N99



33/195

iMac (20-inch, Early/Mid 2009) Symptom Charts — Display 332010-11-24

Display

Backlight Issue/No Backlight

Unlikely cause: hard drive, optical drive, speakers, camera, microphone

Quick Check


Backlight Issue/No Backlight• No image• Partial backlight failure• Backlight ickers• Display dim

1. Check System Preferences > Displays > Brightnesscontrol setting is above minimum.

2. For no-image issues connect an externaldisplay to verify whether iMac video circuitry isfunctioning. Go to No Video if no image is visibleon external display.

Deep Dive


1. Verify boot chime present andfans running when systempowered ON. (Reset SMC andclear PRAM if necessary forproper boot up.)

Yes Power ON self test OK. Bootsequence started. Go to step2.

No Go to Won’t Start Up.

2. Verify whether image is visibleon LCD panel.

Yes Video present. Verify systemfunctionality and return touser or jump to appropriatetroubleshooting ow.

No Go to step 3.

3. Connect supported externaldisplay. Verify whether imageappears on external displaywhen system is booted.

Yes External display detected bysystem. Video circuitry onlogic board functional.Go to step 4.

No Go to No Video.

4. Verify if LCD backlight is ONby looking for faint glowfrom display when viewed indarkened room with brightnessset at maximum.

Yes Internal LCD panel backlightis functioning. Go to step 6.

No Go to step 5.


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5. Shine bright (low heat)ashlight onto the front of theLCD. With the system poweredON verify whether a faint imageis visible.

Yes LCD panel functional butbacklight is not ON. Inspectand reseat four backlight bulbconnectors connecting LCDpanel to inverter, and inverterconnection to logic board.

Go to step 6.No No image or backlight.

Go to step 7.

6. Power ON system. Verifywhether image is visible onLCD panel.

Yes Issue resolved by cable reseat.Return computer to user.

M24

No Replace inverter. Retest. Go tostep 7 if issue is still present.

L03

7. Remove screws securing LCDpanel and inspect LVDS cableand connections for damage.

Reinstall. Power ON system.Verify whether image is visibleon LCD display.

Yes Issue cause by loose LVDSconnection. Verify systemfunctionality and return

system to user.

M24

No Connecting external displayin earlier step conrmed thatlogic board video circuitryis functioning. Replace LVDScable rst, then LCD panel ifthe issue persists. Retest.

L03


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Noise / Unstable Flickering

Unlikely cause: camera, microphone

Quick Check

Symptoms Quick Check Noise / Unstable Flickering• Unstable image• Flickering image• Humming noise from display• High frequency noise from

display

1. Verify that intake vent on the bottom of thesystem is not obstructed.

2. Inspect system for 3rd party software that isbeing used to set fan speeds to a higher thannormal RPM. Some users may use this softwareto monitor and control internal temperaturespotentially causing higher fan speeds to generatehigher than expected noise levels.


1. Verify if user issue is due toickering or an unstable imageon the LCD.

Yes Suspected ickering issue, goto step 2.

No For audible noise issues go tostep 8. All other issues go toappropriate symptom ow.

2. Connect a supported externaldisplay to the DisplayPort.Verify whether issue occurs

with external display.

Yes Suspect issue with videocircuitry. Go to CorruptedVideo.

No Video circuitry OK. Go to step3.

3. Disconnect and carefullyinspect the LVDS and backlightbulb connections for signs ofdamage, corrosion, or pinchedwires. Were any problemsobserved?

Yes Replace damaged cable(s)where needed, otherwisereattach connectors. Retest.

L06

No Go to step 4.

4. Power ON system and verifywhether the issue still occurs.

Yes If connections are secure andthe display is still ickering,go to step 5.

No Issue was caused by a poorconnection between displayand logic board or inverter.Return computer to user.


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5. Shine bright (low heat)ashlight into the front of theLCD. Verify if an image is beingdisplayed when ickering issueis occurring.

Yes Image present but backlightis ickering. Replace inverterthen retest.

L06

No Replace LCD panel thenretest.

L06

6. Verify whether noise varieswhen adjusting the brightnesslevel up and down.

Yes Noise appears to begenerated by the LCD panelor backlight circuitry. Go tostep 7.

No Noise is from another source.Go to Noise/Hum/Vibration.

7. Verify whether noise can beheard when computer is setup with user seated in normaluser position. Adjusting the

brightness level up and downmay be necessary to recreatethe issue.

Yes Replace inverter. Go to step 8. L06

No Noises that are not audiblefrom the normal user position

are considered acceptable.Return computer to user.

8. Verify whether noise is stillpresent.

Yes Replace LCD display. Retest. L06

No Noise issue resolved. Returncomputer to user.

L06


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LCD Image Issues


Quick Check

Symptom Quick Check LCD Issues• Incorrect/missing colors• Distorted/blurred image• Pixel anomalies• Vertical/horizontal lines• Non-uniform brightness

1. Allow display to reach normal operatingtemperature for about 15 minutes beforeevaluating front-of-screen performance.

2. Check display preferences for use of customdisplay prole.

3. Check brightness setting.

4. Clean glass panel while checking for dust/debris.

Deep Dive: GeneralCheck Result Action Code

1. Verify if issue is incorrect/missing colors.

Yes Go to incorrect/missingcolors.

No Go to step 2.

2. Verify if issue is distorted/blurred image.

Yes Go to distorted/blurredimage.

No Go to step 3.

3. Verify if issue is bright or darkpixel anomalies. Yes Go to pixel anomalies.No Go to step 4.

4. Verify if issue is vertical orhorizontal lines.

Yes Go to vertical/horizontallines.

No Go to step 5.

5. Verify if issue is non-uniformbrightness.

Yes Go to non-uniformbrightness.

No LCD functioning OK. Returnto appropriate symptom chart

if user issue is still present.


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Incorrect/Missing Colors


Quick Check

Symptoms Quick Check Incorrect/Missing Colors• Wrong color display• Color/contrast issues

1. Allow display to reach normal operatingtemperature for about 15 minutes beforeevaluating front-of-screen performance.

2. Verify that System Preferences/Display settingsare congured to use the default display prole.

3. Verify System Preferences/Universal Access/Display “Enhance contrast”, “Use grayscale”, and“Black on White/White on Black” settings are setto defaults.

Deep Dive


1. Verify system has been warmedup for ~15 minutes to stabilizebacklight before continuing.

Yes Go to step 2.

No Allow system to warm up forapproximately 15 minutesthen go to step 2.

2. Verify that the LVDS andbacklight connections betweenthe logic board and LCD aresecure.

Yes Go to step 3.

No Reseat connections, replace

damaged cable(s) if needed.Retest.

L14

3. Set desktop pattern in systempreferences to ‘Solid Gray Light’.Verify if incorrect/missing colorissue aects entire display.

Yes Suspect poor videoconnection. Replace LVDScable.

L14

No Go to step 4.

4. Set up display under test sideby side with another known-good display showing thesame image. Verify if issue is

noticeably worse on the displaybeing tested.

Yes Replace LCD panel. L02

No Small variations in coloruniformity across display are

normal and do not warrantreplacement or repair of thedisplay. Return computer touser.


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Distorted/Blurred Image


Quick Check

Symptoms Quick Check Distorted/Blurred Image• Text and graphics appear fuzzy• Image corrupted

1. Set System Preferences/Display LCD panel tonative resolution. Non-native resolutions areunable to produce optimal clarity.

2. Clean outside surface of glass panel usingprovided cleaning cloth.

3. Boot from install DVD to determine whetherpotential software issue exists.



Yes Go to step 2.



2. Verify whether issue is visibleon an external display attached

to the DisplayPort.

Yes Issue is NOT caused byinternal LCD panel.

Go to step 3.No Go to step 5.

3. Remove logic board, inspectconnectors for damage orcorrosion then reinstall. Verifywhether issue still occurs.

Yes Replace logic board.Go to step 4.

M04


M04

4. Verify whether issue is stillpresent with replacement logic

board installed.



M04


40/195


5. Remove LVDS cable from LCDpanel and logic board andcarefully verify whether thereis damage to the cable orconnectors.






M04




L04


41/195


Pixel Anomalies

Unlikely cause: logic board, power supply, hard drive, optical drive, fans, speakers, camera,microphone

Quick Check


Pixel Anomalies• Dark dot anomalies• Bright dot anomalies• Debris on inside surface of

glass panel• Debris on surface of LCD panel

1. Clean outside surface of glass panel usingprovided cleaning cloth.

2. For information about pixel anomalies, see kBasearticle: http://support.apple.com/kb/HT1721


1. Determine if “defects” are dust/debris on surface of glass panelor LCD.

Yes Clean LCD/glass panel.

No Go to step 2.

2. Determine if bright pixeldefects exceed the acceptablenumber. See kBase articlehttp://support.apple.com/kb/HT1721


No LCD panel meets bright pixeldefect specications. Go tostep 3.

3. Determine if dark pixel defectsexceed the acceptable number.See kBase article http://support.apple.com/kb/HT1721

Yes Replace LCD panel L08

No LCD panel meets dark pixeldefect specications. Go tostep 3.

4. Determine if the combinationof bright/dark pixel defectsexceed the acceptablenumber. See kBase articlehttp://support.apple.com/kb/HT1721


No Explain to user that LCDpanel is operating withinspecications for pixel defects.Do not replace LCD panel.

http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721http://support.apple.com/kb/HT1721


42/195


Vertical/Horizontal Lines


Quick Check

Symptoms Quick Check Vertical/Horizontal Lines• Vertical lines• Horizontal lines

1. Boot from install DVD to determine whetherpotential software issue exists.

2. Verify if issue is visible on an external display.

Deep Dive



Yes Go to step 2.



2. Verify whether issue is visibleon an external display attachedto the DisplayPort.

Yes Issue is NOT caused byinternal LCD panel.Go to step 3.

No Go to step 5.

3. Remove logic board, inspect

connectors for damage orcorrosion then reinstall. Verifywhether issue still occurs.

Yes Replace logic board.

Go to step 4.

M04


M04

4. Verify whether issue is stillpresent with replacement logicboard installed.



M04

5. Remove LVDS cable from LCD

panel and logic board andcarefully verify whether thereis damage to the cable orconnectors.




43/195





M04




L04


44/195


Non-Uniform Brightness


Quick Check

Symptoms Quick Check Non-Uniform Brightness• Brightness not uniform• Color not-uniform

1. Verify System Preferences > Displays > Brightnesslevel control is set above minimum.

2. Allow 15 minutes for backlight bulbs to reachnormal operating temperature and output beforeevaluating display.

3. Visually inspect glass panel for presence of dust,cigarette smoke, or other contaminants. Cleanglass panel if needed.


1. Determine if brightnessuniformity issue is visible afterdisplay has warmed up for ~15minutes.

Yes Go to step 2.

No Display backlight can takeseveral minutes to stabilize.Retest. If issue still not visiblereturn computer to user.

2. Use user provided examplesshowing brightness uniformity

issue. Determine if variation inuniformity appears excessivewhen compared to anothersimilar unit.

Yes Go to step 3.

No Demonstrate to user that LCDperforms similarly to anotherunit of the same make andmodel.

3. Remove front bezel andloosen screws securing LCD.Determine if brightnessuniformity improves.

Yes Inspect for mechanicalinterference with screws,chassis, wires making contactwith back of LCD. Reseatcomponents & cables; retest.

No Go to step 4.

4. With LCD panel screwsremoved inspect and thenreconnect the backlightcables. Determine if brightnessuniformity improves.

Yes One or more backlightconnections were loose.Return computer to user.

L14

No Replace LCD panel. L07


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Cosmetic Defects

Quick Check


Cosmetic Defects to LCD• Cracked LCD• Scratched LCD polarizer• Scorched or melted LCD• LCD impact damage• Foreign material on LCD or

back side of glass panel.

1. Determine whether damage was caused byuser environment, accidental damage, or abuse.If applicable, inform the user that Apple doesnot warrant damage caused by accident, abuse,misuse, ood, re, earthquake, or other externalcauses. For more information refer to:http://www.apple.com/legal/warranty

2. For dark and bright pixel anomalies, go toPixel Anomalies.


Quick Check


Uncategorized Symptoms• Unable to locate appropriate

symptom code.

1. Make sure brightness level is set above minimum.

2. Clean glass panel using provided cleaning clothto make sure that external contaminants areremoved prior to evaluating display performance.

3. Allow the iMac display to warm up approximately

15 minutes before evaluating display color andbrightness uniformity performance.

Deep Dive




No Document reported failureand send feedback to

[email protected] stating that a suitablesymptom code wasn’t found.Provide as much detail aspossible.

N99

http://www.apple.com/legal/warrantymailto:smfeedback6%40apple.com?subject=iMac%20%2820-inch%2C%20Early/Mid%202009%29mailto:smfeedback6%40apple.com?subject=iMac%20%2820-inch%2C%20Early/Mid%202009%29http://www.apple.com/legal/warranty


46/195

iMac (20-inch, Early/Mid 2009) Symptom Charts — Mass Storage 462010-11-24

Mass Storage

Hard Drive Not Recognized

Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone

Quick Check


Drive Not Recognized (H01)Drive No Boot (H02)• Flashing Question Mark • Boots to Grey Screen• Boots to Blue Screen

1. Use a known-good mouse. A stuck mouse buttonwill not allow boot.

2. Boot from Install DVD. Verify S.M.A.R.T. status ofdrive using Disk Utility.

3. Repair disk using Disk Utility.

4. Erase disk and reinstall Mac OS using Install DVD.5. Use Target Disk Mode to attempt to mount

user’s hard drive on a known-good computer. Ifmounted, use Disk Utility on host computer forQuick Checks 2, 3 and 4.

Deep Dive


1. Boot from Install DVD and run

Disk Utility. Verify that userhard drive is available for DiskUtility to repair.

Yes Go to step 2.

No Go to step 5.

2. Run Disk Utility ‘Repair Disk’function and verify that itcompletes successfully.

Yes Go to step 3.

No Go to step 4.

3. Reboot computer. Verify thatsystem boots successfully andthat Disk Utility ‘Verify’ functionreports no errors.

Yes Data error Issue resolved.Return computer to user.

H07

No Go to step 4.

4. Erase disk and reinstall Mac OSusing Install DVD. Verify thatinstallation process completes.

Yes Go to step 8.

No Go to step 5.

5. Inspect hard drive SATA andpower cables and connectorsfor bent pins, or other damageto the cable.

Yes Replace damaged cable.Go to step 8.

H04

No Go to step 6.


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6. Reseat SATA and logic boardhard drive connections andverify whether computer startsup.

Yes Go to step 8.

No Replace SATA cable.Go to step 8.

H04

7. Test with known-good harddrive. Verify that system bootssuccessfully and that Disk utility‘Verify’ function reports noerrors.

Yes Install user drive. Go to step 9.

No SATA cable veried orreplaced and known-goodhard drive installed. Suspectpossible SATA controllerissues. Replace logic board.Go to step 1.


Yes Issue resolved. Return systemto user.

No Go to step 7.


Yes Issue resolved.No Hard drive appears to be

defective. Go to step 10.

10. Replace hard drive. Does driveformat correctly with a GUIDpartition map and install MacOS X without errors?

Yes Issue resolved by replacinghard drive.

H05

No SATA cable veried orreplaced and new hard driveinstalled. Replace logic board.

M19


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Hard Drive Read/Write Error


Quick Check

Symptoms Quick Check Drive Read/Write Error (H03)Drive Bad Sector/Defective (H05)Drive Formatting Issues (H07)• Cannot save documents• Read/write error message• Hang when accessing or saving

data

1. Boot from Install DVD. Verify S.M.A.R.T. status ofdrive using Disk Utility.


3. Erase disk and reinstall Mac OS using Install DVD.

4. Use Target Disk Mode to mount user’s hard driveon a known-good computer. Use Disk Utility onhost computer for Quick Checks 1 through 4.



Yes Go to step 2.

No Go to step 3.


Yes Data error. Issue resolved.Return computer to user.

H07

No Go to step 3.

3. Erase disk and reinstall Mac OSusing Install DVD. Verify thatinstallation process completes.

Yes Go to step 7.

No Go to step 4.

4. Inspect hard drive SATA andpower cables and connectorsfor bent pins, or other damageto the cable.

Yes Replace damaged cable.Go to step 7.

H04

No Go to step 5.

5. Reseat SATA and logic boardhard drive connections andverify whether computer startsup.

Yes Go to step 7.

No Replace SATA cable.Go to step 7.

H04

6. Test with known-good harddrive. Verify that system bootssuccessfully and that DiskUtility ‘Verify’ function reportsno errors.

Yes Install user drive. Go to step 8.

No SATA cable veried orreplaced and known-goodhard drive installed, Replacelogic board.


49/195



Yes Issue resolved. Return systemto user.

No Go to step 6.


Yes Issue resolved.

No Hard drive appears to bedefective Go to step 9.

9. Replace user hard drive. Doesdrive format correctly with aGUID partition map and installMac OS X without errors?

Yes Issue resolved by replacinghard drive.

No SATA cable veried orreplaced and new hard driveinstalled. Replace logic board.

Hard Drive NoisyUnlikely cause: LCD panel, logic board, power supply, speakers, camera, microphone

Quick Check


Hard Drive Noisy (H06)• Noise during start up• Noise during operation• Noise when drive is copying or

saving data

1. Start up from Install DVD. Verify S.M.A.R.T. statusof drive using Disk Utility.


3. Determine if noise is comparable to anothermachine of the same model.

Deep Dive


1. Boot from the Install DVD andrun Disk Utility. Verify that userhard drive is available for DiskUtility to repair.

Yes Go to step 2.

No Go to Hard Drive NotRecognized.


Yes Go to step 3.

No Go to step 4.


50/195


3. Restart the computer. Verifywhether the noise is stillpresent.

Yes Go to step 6.

No Data error issue resolved byDisk Utility. Return system touser.

H06

4. Erase disk and reinstall Mac OSusing Install DVD. Verify thatinstallation process completes.Note: Make sure data has beenbacked up before erasing harddrive.

Yes Go to step 3.

No Replace hard drive.Go to step 5.

H06

5. With replacement hard driveinstalled reboot computer.Verify whether noise is stillpresent.

Yes Go to step 6.

No Issue resolved by replacinghard drive.

6. With hard drive removed

verify that rubber vibrationisolation grommets areproperly installed in hard drivemounting bracket.

Yes Go to step 8.

No Replace hard drive mountingbracket. Go to step 7.

H06

7. Reboot computer. Verifywhether noise is still present.

Yes Replace hard drive.Go to step 6.

No Noise caused by chassis/ harddrive bracket. Return systemto user.

8. Disconnect hard drive SATA and

power connections then bootfrom the Install DVD. Determineif noise is caused by the fans inthe computer.

Yes Go to Fan Failures/Thermal

Issues.No Go to step 9

9. Disconnect the hard diveSATA and optical drive thenboot from an external volume.Determine if the noisedisappears when the opticaldrive has been disconnected.

Yes Posible optical drive or mediaissue. Go to Optical DriveNoisy.

No Noise issue still present, butdoes not appear to be causedby hard drive. Go to Noise/Hum/Vibration.


51/195


Optical Drive Not Recognized


Quick Check

Symptoms Quick Check Drive Not Recognized/Mount(J05)• Discs inject and eject, but do

not appear in Finder

1. Use Apple System Proler Serial-ATA section tosee if the optical drive and any inserted mediaappears.

2. Check Finder Preferences and make sure “CD’s,DVD’s and iPods” is checked under “Show theseitems on the desktop” in the General section.

3. Check both CD and DVD media. If only one typeof media is recognized, there is a laser issue.Replace optical drive (J03).

Deep Dive


1. Is the optical drive listed in theSerial-ATA section of the AppleSystem Proler?

Yes Go to step 2.

No Go to step 3.

2. Test both CD and DVD media.Can drive read both CD mediaand DVD media?

Yes Go to step 6.

No Drive has a laser issue.Replace the optical drive. Ifboth types media fail, checkFinder Preferences then go tostep 3.

J03

3. Reseat SATA cable connectionsat logic board and optical drive.Do both types of media readreliably now?

Yes Go to step 6.

No Go to step 4.

4. Connect known-good opticaldrive to SATA cable. Do bothtypes of media reliably read

now?

Yes SATA cable and port on logicboard good. Go to step 5.

No Replace SATA cable and test(X03). If issue persists, replacelogic board (M19). Go to step6.


52/195


5. Connect original optical driveto known-good SATA cable. Doboth types of media reliablyread now?

Yes SATA cable issue. ReplaceSATA cable. Go to step 6.

X03

No Go to step 2.

6. Test read compatible known-

good CD and DVD media(Install DVD). Verify media isrecognized and reads reliably.

Yes Issue resolved.

No Replace optical drive. J03

Optical Drive Won’t Accept/Eject Media


Quick Check


Drive Won’t Accept Media (J01)Drive Won’t Eject Media (J02)• Cannot insert a disc into the

drive• Cannot eject a disc placed into

the drive

1. Use Apple System Proler Serial-ATA sectionto see if the optical drive appears. If not, go toOptical Drive Not Recognized.

2. Restart computer and hold down mouse buttonor keyboard eject key to cycle optical drive.

3. Inspect optical drive slot for obstructions.

Deep Dive


1. Verify that optical drive is listedin the System Proler devicetree for Serial-ATA devices.

Yes Optical drive communicatingwith logic board. Go to step 5.

No Logic board notcommunicating with opticaldrive. Go to step 2.

2. Verify all connection betweenlogic board, ex cable, andoptical drive are secure. Visually

inspect cables and connectorsfor any debris, damage or bentpins. Verify that the opticaldrive is listed in the SystemProler device tree.

Yes Optical drive communicatingwith logic board. Go to step 5.

No Replace damaged cablesand retest. If connectionsare good and with no visiblecable damage, go to step 3.

X03


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3. Connect known-good opticaldrive to SATA cable. Verify thatknown-good optical drive islisted in the System Prolerdevice tree.

Yes Go to step 4.

No Suspect SATA cable.Go to step 7.

4. With known-good optical driveinstalled, test for media inject/eject. Verify drive accepts andejects known-good media.

Yes Known-good optical driveresolved inject/eject issue.Replace optical drive.

J03

No Go to step 7.

5. Inspect optical drive slot duringdisc insert/ eject. Verify thatdiscs can be inserted easily.

Yes Go to step 6.

No Replace damaged opticaldrive. Note: It may be possibleto reinstall the optical drivebezel to correct this issue.

J03

6. With known-good opticalmedia (Install disc), test formedia inject/eject. Does driveaccept and eject known-goodmedia?

Yes Media issue. No repairnecessary. Suggest userinvestigate use of dierentmedia.

No Go to step 3.

7. Replace SATA cable then testfor media inject/eject. Doesdrive inject and eject known-good media?

Yes SATA cable resolved issue.Return system to user.

X03

No SATA cable veried orreplaced, and optical driveveried or replaced. Replace

logic board and retest.

M19


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Optical Drive Read/Write Error


Quick Check

Symptoms Quick Check Drive Read/Write Data Error (J03)• Errors when writing optical

media.• Errors when reading optical

media.• Hang when accessing or

preparing to write data.

1. Test optical media in another drive of the sametype in the same type of computer to rule outmedia issue.

2. Check with known-good discs like the Installdiscs that came with the computer.

3. For write issues, check with known-good mediathat performs well in another computer andoptical drive of the same type.

4. Check both CD and DVD media. If only one typeof media is producing errors, there is a laser issue.Replace optical drive (J03).

Deep Dive


1. Is media free to spin withoutoptical drive scraping edge orsurface of media?

Yes Go to step 2.



Yes Go to step 6.

No Drive has a laser issue.Replace the optical drive. Ifboth types media fail, go tostep 3.

J03


Yes Go to step 6.

No Go to step 4.

4. Connect known-good opticaldrive to SATA cable. Do bothtypes of media reliably readnow?

Yes SATA port on logic boardgood. Go to step 5.

No SATA port on logic board bad.Replace logic board.

M19



X03



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6. Test write data to compatibleCD and DVD media. Verifyburned media is recognizedand reads reliably.

Yes Issue resolved.


Optical Drive Not Performing to Specications


Quick Check


Optical Drive Not Performing toSpecications (J07)• Read or write speeds slower

than expected

1. Test optical media in another drive of the sametype in same type of computer to rule out mediaissue.

2. For write issues, check with known-good mediathat performs well in another computer and driveof the same type.

3. Check both CD and DVD media. If only one typeof media is producing errors, you have a laserissue. Replace the optical drive (J05)

Deep Dive



Yes Go to step 6.


J03


Yes Go to step 6.

No Go to step 4.





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X03


5. Test write data to compatible

CD and DVD media. Verifyburned media is recognizedand reads reliably.

Yes Issue resolved.

No Go to step 7. J03

6. The balance of some mediamay not perform at higherspeeds supported by the drive.Does slowing the requestedburn speed allow the discs towrite reliably?

Yes Media issue. No repairnecessary.


Optical Drive Noisy


Quick Check


Optical Drive Noisy (J04)• Noise during boot• Noise during operation

• Noise when drive is copying orwriting data

1. Test optical media in another drive of the sametype in same model of computer to rule outmedia issue.

2. Test with known-good discs like the Install discsthat came with the computer.

3. Check to see if noise occurs without media in thedrive. If so, check if hard drive (H06) or fan (M18)caused noise.

Deep Dive



Yes Go to step 6.


J03


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Yes Go to step 6.

No Go to step 4.






X03


5. Test write data to compatible

CD and DVD media. Verifyburned media is recognizedand reads reliably.

Yes Issue resolved.

No Go to step 7 J03

6. The balance of some mediamay not perform at higherspeeds supported by the drive.Does slowing the requestedburn speed allow the discs towrite reliably?

Yes Media issue. No repairnecessary.






No Document reported failureand send feedback [email protected] stating that a suitable

symptom code wasn’t found.Provide as much detail aspossible.

N99



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iMac (20-inch, Early/Mid 2009) Symptom Charts — Communications 582010-11-24

Communications

AirPort/Bluetooth Issues

Quick Check


AirPort/Bluetooth Issues• Unable to join networks or pair

devices• AirPort card not available• Intermittent device or

connection dropouts• Limited wireless range

1. Verify that AirPort or Bluetooth is turned ON andfor AirPort issues make sure that a network isselected.

2. For AirPort, check if the wireless access pointrequires special connection and encryptionprotocols.

3. Check for nearby sources of interference such asmicrowave ovens or cordless phones. See kBasearticle http://support.apple.com/kb/HT1365

4. Check the number of users trying to use AirPortin the area for possible network congestion(available bandwidth).

5. Isolate potential OS issues by starting up fromthe original Install media for the computer, thesame model computer in Target Disk Mode, orcompatible known-good OS on an external drive.Both AirPort and Bluetooth services are availablewhen booted from the Install disc.

Deep Dive


1. Open System Proler. AirPortis listed under Network, whileBluetooth is listed under USB. IsAirPort/Bluetooth recognized?

Yes Install all software updates forAirPort/Bluetooth.AirPort, go to step 3.Bluetooth, go to step 4.

No Remove and reinstall theAirPort/Bluetooth card andretest. If still unrecognized,

replace the AirPort/Bluetoothcard. Go to step 2.

M11

http://support.apple.com/kb/HT1365http://support.apple.com/kb/HT1365


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2. Ensure that antenna cable(s)are connected properly andnot damaged, and all softwareupdates available for AirPort/Bluetooth have been installed.Do connection issues persist?

Yes AirPort, go to step 3.Bluetooth, go to step 4.

No Issue resolved.

3. Create a computer-to-computer network withanother Macintosh computerusing AirPort. See kBase articlehttp://docs.info.apple.com/article.html?path=AirPort/5.0/en/ap2110.html. Can youconnect successfully?

Yes Network or channel issue.Go to step 5.

No Double check any passwordrequired. Try connectinganother known-goodcomputer to the network.If test computers connect,replace AirPort card.Go to step 6.

M11

4. Make sure that your Bluetooth

device is in discoverable mode,and that your computer is alsoin discoverable mode. Can yousuccessfully and reliably pair adevice now?

Yes Issue resolved.

No Replace Bluetooth card.Go to step 6.

M11

5. Try connecting to a known-good network that does notrequire password or has MACaddress ltering enabled. Canyou connect to a networkreliably now?

Yes Troubleshoot local network.Possible password or MACaddress ltering issue.

No Replace AirPort card.Go to step 6

M11

6. With the AirPort/Bluetooth cardreplaced and antenna cableinspected for damage andreplaced if necessary, are theconnection issues resolved?

Yes Issue resolved.

No Replace logic board. M11

http://docs.info.apple.com/article.html?path=AirPort/5.0/en/ap2110.htmlhttp://docs.info.apple.com/article.html?path=AirPort/5.0/en/ap2110.htmlhttp://docs.info.apple.com/article.html?path=AirPort/5.0/en/ap2110.htmlhttp://docs.info.apple.com/article.html?path=AirPort/5.0/en/ap2110.htmlhttp://docs.info.apple.com/article.html?path=AirPort/5.0/en/ap2110.htmlhttp://docs.info.apple.com/article.html?path=AirPort/5.0/en/ap2110.html


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AirPort Card Kernel Panic

Quick Check


AirPort Card Kernel Panic• Kernel panic on startup• Kernel panic or freezing while

attempting to connect to wi-networks

•

imac20 early mid2009 technician guide

Documents