Symptom Charts | Apple MD094LL/A guide

LED Functions	30
LED Startup Sequence		31
Logic Board Test Points		32
Functional Overview 33
Block Diagram	34

Symptom Charts 35

Startup and Power 35

No Power, Dead Unit 35

Won’t Start Up 37

Intermittent Shutdown 39

Kernel Panic, System Crashes 44

No Video 46

Corrupted Video 48

Burnt Smell/Odor 51

Uncategorized Symptoms 52

Display 53

Backlight Issue/No Backlight 53

Noise / Unstable Flickering 55

LCD Image Issues 58

Incorrect/Missing Colors 60

Distorted/Blurred Image 62

Pixel Anomalies 64

Vertical/Horizontal Lines 66

Non-Uniform Brightness / Color 68

Cosmetic Defects 69

Uncategorized Symptoms 69

Mass Storage 70

Hard Drive Not Recognized 70

Optical Drive Not Recognized 76

Optical Drive Won’t Accept/Eject Media 77 Optical Drive Read/Write Error 78

Optical Drive Not Performing to Specifications 80 Optical Drive Noisy 82

SD Card Will Not Insert Into Slot 83 SD Card Not Recognized 84 Uncategorized Symptoms 85

Communications 86

AirPort/Bluetooth Issues 86

AirPort Card Kernel Panic 89

Ethernet Port/Device Issue 90

Wireless Input Device Does Not Pair 91

Uncategorized Symptoms 93

Input/Output Devices 94

Apple Remote Inoperable 94 Audio: Microphone 96

Image 4

Apple MD094LL/A manual Symptom Charts

Contents

 Apple Technician Guide IMac 27-inch, Mid USA Troubleshooting Contents About This GuideBasics Symptom Charts Take Apart General Information Bluetooth Board LCD Panel Handling the Panel Vertical Sync Cable Vsync Video Card Additional Procedures Views  Apple Technician Guide About This Guide Updates Updated 9 SeptemberUpdated 9 August Feedback  Apple Technician Guide Basics Overview Identifying Features Product Configurations Safety Precautions Serial Number Location New Accessories Magic Trackpad About the Indicator Light Pairing the Magic Trackpad Apple Battery Charger Batteries  Apple Technician Guide Troubleshooting General Troubleshooting Wireless TroubleshootingUpdate System Software & Firmware Troubleshooting Theory Common Reset Procedures Power On Self Test Post Hardware vs. Software Resetting the System Management Controller SMC Resetting Parameter RAM Pram Starting Up in Safe Mode Removing the Battery, Measuring DC Voltage Diagnostics Sensors ErrorsSensor Suggested Action Logic board this sensor is part Video card assembly Board Sensor cable if damaged Sensor Connector Locations Top Side of Logic Board Sensor Locations Sensor Connector Location Back Side of Logic Board Diagnostic LEDs Location of Diagnostic LEDs LED Functions LED #1LED #2 LED #3 LED #1 + LED #2 = Power available, and system is powered on LED #1 = Power availableLED Startup Sequence According to user setup Board, to enable backlightLogic Board Test Points Function Functional Overview Block Diagram Refer to this diagram to see how modules are interrelated Symptom Charts No Power, Dead UnitSymptoms Quick Check No Power, Dead Unit Check Result Action Code To Won’t Start Up symptom Symptoms Quick Check Won’t Start Up Safe Boot, Safe Mode?Sequence and error codes, symbols for Won’t Start Up Using a digital multimeter Go to AirPort Card KernelGo to Hard Drive Not Go to Optical Drive Not Troubleshooting Shutdown Causes Intermittent Shutdown Power-related system shut downs Make sure that power cord is securely attached Symptoms Quick Check Intermittent ShutdownPowers off during startup Hard drive, update OS with OS on an external drive. Verify Recognized symptom flowSupply replacement Cord and AC outlet, Verify if X03 M23X22 P17 Symptoms Quick Check Kernel Panic, System Crashes Kernel Panic, System CrashesAbout You need to restart your computer Kernel panic messages Go to Camera Issues or Go to AirPort/BluetoothX01 Go to SD Card Not Symptoms Quick Check No Video Go to Backlight Issue/NoNo Video Go to Won’t Start Up Diagnostic LEDs on edge Locate diagnostic LEDs onM03 L03 Symptoms Quick Check Corrupted Video If issue cannot be seen in the screenshot thenCorrupted Video Video drivers, software, or video/logic board M04 Utility Diagnostic and enter Resolved with replacement LCD panelDisconnect DisplayPort cable Yes Replace DisplayPort cable Cable and go to step Symptoms Quick Check Burnt Smell/Odor Burnt Smell/Odor No Power, Dead Unit symptom flow Uncategorized SymptomsSmfeedback2@apple.com Backlight Issue/No Backlight Symptoms Quick Check Backlight Issue/No Backlight Panel. Run Apple Service Display Utility to verify Panel with correct backlightLogic board and LCD panel Display Display Backlight Issue / No Backlight Symptoms Quick Check Noise / Unstable FlickeringNoise / Unstable Flickering Run Apple Service Display Utility to verify the resolution Symptom flow Issue resolved When adjusting brightness levelTo Noise/Hum/Vibration LCD Image Issues Go to pixel anomalies Go to vertical/horizontalLines Go to non-uniform Symptoms Quick Check Incorrect/Missing Colors Incorrect/Missing Colors Yes Replace LCD panel. Run L02 Symptoms Quick Check Distorted/Blurred Image Clean outside of glass panelBoot from install DVD to determine if a potential Software issue exists Reinstalling internal DisplayPort Pixel Anomalies L08 Do not replace LCD panel Symptoms Quick Check Vertical/Horizontal Lines Vertical/Horizontal LinesNoise / Unstable Flickering M24 Issue resolved. If video card Service Display Utility toL04 Service Display Utility. To Symptoms Quick Check Non-Uniform Brightness/ColorNon-Uniform Brightness / Color Cosmetic Defects Symptoms Quick Check Cosmetic Defects to LCDCracked glass panel Symptoms Quick Check Drive Not Recognized Drive No BootError codes, symbols Hard Drive Not Recognized Check that the 4 wire Sata Yes Replace any damaged Sata Power cable carrying 12vLogic board Reboot computer. Verify if Yes System boots successfully To user Hard Drive Read/Write Errors Go to Optical Drive Read Mac OS without errors H04If computer starts up H03 Symptoms Quick Check Hard Drive Noisy Hum/Vibration symptomHard Drive Noisy Refer to Kbase article TS3204 Evaluating Hard drive H06Go to Fan Failures/Thermal Symptoms Quick Check Drive Not Recognized/Mount Optical Drive Not Recognized Symptoms Quick Check Drive Won’t Accept Media Not Recognized symptom flowOptical Drive Won’t Accept/Eject Media Drive Won’t Eject Media Symptoms Quick Check Drive Read/Write Data Error Optical Drive Read/Write ErrorJ03 Replace optical drive Install known-good optical Drive SATA+Power cableIssue resolved CD and DVD media. Verify if Diagnostics, replace optical Drive Optical Drive Not Performing to Specifications Symptoms Quick Check Optical Drive Not Performing toSpecifications Same type to rule out media issue Running diagnostics, replace Optical drive Symptoms Quick Check Optical Drive Noisy J04 Optical Drive NoisyTest optical drive with different Compare system with similar SD Card Will Not Insert Into Slot Seat into slot Media Cards MMCVerify if known-good SD card Tighten SD reader board Now fits in slot Screws. Go to step Symptom Quick Check SD Card Not Recognized SD Card Not Recognized Correctly read and written AirPort/Bluetooth Issues Issue. See kBase #HT1365 Airport potentialKBase #HT1365 AirPort Potential source Interference Html?path=AirPort/5.0/en N04 M11 Bluetooth issues are resolvedDiscoverable mode. Verify if Symptoms Quick Check AirPort Card Kernel Panic AirPort Card Kernel Panic Ethernet Port/Device Issue Symptoms Quick Check Ethernet Port/Device Issue Wireless Input Device Does Not Pair KBase #HT2532 Mac OS How to change the MTU forTroubleshooting purposes Html?path=Mac/10.6 Go to Wireless Input Device Loses Connection symptom Connector is damaged Go to Wireless Input Device Loses Connection symptomVerify System Preferences/Network settings Go to step With customer’s mouse Yes Symptoms Quick Check Apple Remote Inoperable Apple Remote Inoperable That computer now Yes Lens blocked or sensor notResponds to Apple Remote Audio Microphone Symptoms Quick Check Audio MicrophoneM09 Inspect microphone cable Yes Replace rear housing Audio Built-in Speakers Have Distorted SoundL14 Is normal during playback Symptoms Quick Check See kBase #TS1574 Troubleshooting issuesAudio No Audio from Built-in Speakers Audio Device, replace audio cable Output and verify that InternalBoard Go to System Preferences Go to step Quality is acceptable Set speaker balance 100% Persists, verify if symptom has Camera Issues Symptoms Quick Check Camera Issues FireWire Device Not Recognized For external FireWire drives, make sure anyUnplug all FireWire devices Mode. Verify if FireWire device Software on User account. Issue Symptoms Quick Check USB Device Not Recognized USB Device Not Recognized Bluetooth not recognized M15 Wired Keyboard Does Not Function Properly Symptoms Quick Check Wired Keyboard Does NotFunction Properly Go to Keyboard Specific Keys Do Not Respond Go to Optical Drive Won’t Accept/Eject Media Input Device Doesn’t Pair symptom flow to Wired Keyboard/Mouse Not RecognizedKeyboard Specific Keys Do Not Respond Clean your Mighty Mouse Troubleshooting Mighty Mouse and determiningGo to USB Device Not Not Function Properly Pair with computer Not charge batteries Not charge batteries Symptoms Quick Check Apple Wireless Mouse/Magic Apple Wireless Mouse/Magic Trackpad Erratic TrackingTrackpad erratic tracking Wireless Input Device Loses Connection K08 Apple Battery Charger Does Not Charge Batteries Charge BatteriesP01 P10 Was installed in charger Software is installed and up-to-date, and thatVary from 80% to almost full Device is supported with user’s system Symptoms Quick Check Noise/Hum/Vibration Stand/Hinge Issues symptom flowUnstable Flickering symptom flow Noise/Hum/Vibration Location table in General Go to Optical Drive NoisyGo to Audio Built-in Speakers Have Distorted Board. Go to Noise/Unstable From fan housing Reinstall fans while carefully YesBeing used When working around an Energized system P04 Fan Failures / Thermal Issues Symptoms Quick Check Fan Failures / Thermal IssuesVerify that vents on bottom and back of system System feels very hot Stand/Hinge Issues Symptoms Quick Check Stand/Hinge IssuesX23 Manuals available at http//support.apple.com Symptoms Quick Check Physical Damage Physical DamageVerify if damage caused by user environment Broken glass  Service Source Take Apart General Information Opening the UnitRequired Tools KBase #HT3452 Hand Tools for Desktop and Portable Repairs Cleaning Tools Starter Kit Required Special Tools for Glass Panel Cleaning & Handling the Glass Panel Do’s and Don’ts How to Remove a Broken Glass Panel Handling a Broken Glass Panel IMac 27-inch, Mid 2010 Take Apart General Information IMac 27-inch, Mid 2010 Take Apart General Information IMac 27-inch, Mid 2010 Take Apart General Information IMac 27-inch, Mid 2010 Take Apart General Information Safety Logic Board Handling Reassembly StepsScrew Sizes Access Door First StepsTools ESD mat and wrist strap Phillips #2 screwdriver Removal Access door MemoryRemove ESD mat and wrist strap Reassembly Shut down unit Unplug all cables Put on ESD strap Glass PanelMicrofoam bag Removal Reassembly Set unit in upright position to minimize settling of dust IMac 27-inch, Mid 2010 Take Apart Glass Panel Camera Glass panel Removal Reassembly LCD Panel Reassembly Note Remove 8 T10 screws IMac 27-inch, Mid 2010 Take Apart LCD Panel Pull display forward slightly to disconnect Important Panel Handling information Replacement LCD panel includes Vsync cable Mylar tape Aluminum tape Handling the Panel Important Handle LCD panel by the edges only Connect the DisplayPort cable IMac 27-inch, Mid 2010 Take Apart LCD Panel IMac 27-inch, Mid 2010 Take Apart LCD Panel Vertical Sync Cable Vsync Pull cable straight out of connectorGlass panel LCD panel Peel black insulator to access cable LED Temp Sensor Cable DisplayPort Cable No tools are required for this procedurePeel back mylar tape securing cable to LCD panel IMac 27-inch, Mid 2010 Take Apart DisplayPort Cable Audio Ports and Cable Torx T10 screwdriver ESD mat and wrist strap Also help keep audio cable aligned while tightening screws AirPort Antenna Magnetized Torx T8 screwdriver ESD-wrist strap and mat Disconnect antenna cable from AirPort card AirPort Card Magnetized Torx T6 screwdriver ESD-wrist strap and mat Remove 1 T6 screw 922-8579 Hold card by edges and pull it out of the slot Glass panel LCD panel AirPort card AirPort Carrier BoardMagnetized Torx T10 screwdriver ESD-wrist strap and mat Disconnect Airport data cable Remove 2 T10 screws 922-6850 Glass panel LCD panel AirPort carrier board AirPort CableTools ESD-wrist strap and matt Black stick Removal Bluetooth Antenna Disconnect Bluetooth antenna from the Bluetooth card Bluetooth Board Removal LED Backlight Board Removal Power Supply Voltage Remove 4 T10 screws Self-tapping, 922- 6850, short S Longer self-tapping 922- 9593, long L Route AC power inlet cable over power supply pressure wall Glass panel LCD panel Power supply Backlight Pressure Wall Lift pressure wall off posts in the rear housing Power Supply/Hard drive Pressure Wall Lift pressure wall off posts in the rear housing Replace Kapton tape securing AC inlet cable to pressure wall Hard Drive Removal Orient drive with circuit board facing up as shown Hard Drive Sensor Cable Glass panel LCD panel Hard drive Each hard drive manufacturer has a unique sensor cable Optical Drive Torx T10 screwdriver ESD-wrist strap and mat Removal IMac 27-inch, Mid 2010 Take Apart Optical Drive Reassembly Replace screws in order shown Glass panel LCD panel Optical drive Optical Sensor CableTools ESD-wrist strap and mat Peel up foam gasket to release sensor end of cable Optical Drive Fan Remove 1 T10 screw 922-9236 EEE code SD Card ReaderTorx T8 screwdriver ESD-wrist strap and mat Black stick Removal Reassembly SD Card Reader Cable Glass panel LCD panel Optical drive Optical drive fan IMac 27-inch, Mid 2010 Take Apart SD Card Reader Cable IR Board and Cable ESD-wrist strap and mat Black stick Removal Logic Board Transfer this jumper if replacing the logic board Power button CPU fan Skin temp sensor 922-6800, 2 short 922-9237, 2 20mm, medium Carefully lift board up and out of rear housing Handling Logic Board Reassembly IMac 27-inch, Mid 2010 Take Apart Logic Board IMac 27-inch, Mid 2010 Take Apart Logic Board IMac 27-inch, Mid 2010 Take Apart Logic Board Hard drive temp sensor or HD jumper if SSD-only config IMac 27-inch, Mid 2010 Take Apart Logic Board Video Card Removal IMac 27-inch, Mid 2010 Take Apart Video Card Solid State Drive SSD Torx T8 screwdriver Black stick ESD-wrist strap and mat Removal Use a black stick to pry pressure wall off rear housing Lift pressure wall and SSD drive from rear housing Reassembly SSD Data Cable Disconnect SSD data cable from top of SSD drive Optical/MXM Pressure Wall Remove 1 T8 screw on pressure wall Hard Drive Data Cable Removal IMac 27-inch, Mid 2010 Take Apart Hard Drive Data Cable Optical Drive Data Cable Replacement Note Disconnect optical data cable from back side of logic board Battery Black stick ESD mat and wrist strap Make sure battery socket is open and free of dust Right Speaker Removal CPU Fan Remove 2 T10 shoulder screws Route sensor cable through clip on fan Ambient Temp Sensor Black stick ESD-wrist strap and mat Release sensor cable from 2 cable clips on CPU fan Left Speaker Removal IMac 27-inch, Mid 2010 Take Apart Left Speaker Hard Drive Fan Removal Mechanism Cover ESD-wrist strap and mat Magnetized Torx T10 screwdriver 922-6800 Peel up aluminum tapePry cover off mechanism Stand No preliminary steps are required to remove the stand Remove the access card Remove 8 T10 screws 922-8174 Stand the computer upright Mechanism Remove 6 T10 screws 922-9238 Lift mechanism off rear housing Bluetooth Cable Removal IMac 27-inch, Mid 2010 Take Apart Bluetooth Cable Glass panel LCD panel Camera Hard drive Power supply Camera Cable Disconnect camera cable #5 from the top of logic board IMac 27-inch, Mid 2010 Take Apart Camera Cable Cable, AC/DC Power/Backlight Sata Removal SATA, SSD Disconnect SSD drive power cable from top of SSD drive 2010-09-09 Refer to the rear housing procedure Microphone Cable Rear Housing When replacing the rear housing follow these important steps Reinstall 4 screws Transfer Camera and Reuse Thermal Paste IMac 27-inch, Mid 2010 Take Apart Rear Housing  Service Source Additional Procedures Retrieving Mechanism Overview Removal 2010-09-09 2010-09-09  Service Source Views Exploded Views Exploded View #1 Exploded View #2 Exploded View #3 External Views Rear View Ports Internal Views Photo of Components below LCD Photo of Components in the Rear Housing Logic Board, Front Side Logic Board, Back Side Screw Chart 922-9246 922-9239 922-4723922-9247 922-8579 922-6850 922-9244 922-9593 922-9241 922-9236 922-6800 922-9237 922-9243 922-9242 922-9238922-8174 922-9488 922-7018 922-7971