Apple Technician Guide
iMac (21.5-inch, Mid 2010)
Updated: 2010-09-03
Apple Inc.
© 2010 Apple Inc. All rights reserved.
Under the copyright laws, this document may not be copied, in whole or in part, without the
written 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.
Apple
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Cupertino, CA 95014-2084
USA
+ 1 408 996 1010
www.apple.com
Apple, the Apple logo, Mac, and Macintosh are trademarks of Apple Inc., registered in the U.S.
and other countries.
iMac (21.5-inch, Mid 2010)
Contents
About This Guide
Updates 9
Updated 3 September 2010 9
Apple Technician Guide introduced 27 July 2010 9
Feedback 9
Basics
Overview 11
Identifying Features 12
Product Congurations 12
Safety Precautions 13
Serial Number Location 14
New Accessories 15
Magic Trackpad 15
Apple Battery Charger 17
Troubleshooting
General Troubleshooting 19
Wireless Troubleshooting 19
Update System Software & Firmware 19
Troubleshooting Theory 19
Hardware vs. Software 19
Common Reset Procedures 20
Power On Self Test (POST) 20
Resetting the System Management Controller (SMC) 20
Resetting Parameter RAM (PRAM) 21
Starting Up in Safe Mode 21
Removing the Battery, Measuring DC Voltage 22
Diagnostics 23
Sensor and Fan Connector Locations 25
Diagnostic LEDs 26
LED Startup Sequence 27
Logic Board Test Points 28
Block Diagram 29
Functional Overview 30
Symptom Charts 31
Startup and Power 31
No Power, Dead Unit 31
Won’t Start Up 33
Intermittent Shutdown 35
Troubleshooting Shutdown Causes 35
Kernel Panic, System Crashes 39
No Video 41
Corrupted Video 43
Burnt Smell/Odor 46
Uncategorized Symptoms 47
Display 48
Backlight Issue/No Backlight 48
Noise / Unstable Flickering 50
LCD Image Issues 52
Incorrect/Missing Colors 53
Distorted/Blurred Image 54
Pixel Anomalies 56
Vertical/Horizontal Lines 57
Non-Uniform Brightness 59
Cosmetic Defects 60
Uncategorized Symptoms 60
Mass Storage 61
Hard Drive Not Recognized 61
Optical Drive Not Recognized 67
Optical Drive Won’t Accept/Eject Media 68
Optical Drive Read/Write Error 70
Optical Drive Not Performing to Specications 72
Optical Drive Noisy 73
SD Card Will Not Insert Into Slot 74
SD Card Not Recognized 75
Uncategorized Symptoms 76
Communications 77
AirPort/Bluetooth Issues 77
AirPort Card Kernel Panic 80
Ethernet Port/Device Issue 81
Wireless Input Device Doesn’t Pair 82
Uncategorized Symptoms 84
Input/Output Devices 85
Apple Remote Inoperable 85
Audio: Microphone 87
Audio: Built-in Speakers Have Distorted Sound 88
Audio: Built-in Speakers Have No Sound 89
Camera Issues 91
FireWire Device Not Recognized 92
USB Device Not Recognized 94
Wired Keyboard Does Not Function Properly 96
Keyboard: Specic Keys Do Not Respond 98
Wired Keyboard/Mouse Not Recognized 98
Wireless Input Device Does Not Pair 100
Apple Wireless Mouse/Magic Trackpad Erratic Tracking 102
Wireless Input Device Loses Connection 103
Mechanical 107
Noise/Hum/Vibration 107
Fan Failures / Thermal Issues 110
Stand/Hinge Issues 111
Physical Damage 112
Uncategorized Symptoms 112
Take Apart
General Information 114
Opening the Unit 114
Required Tools 114
Required Special Tools for Glass Panel 115
Cleaning Tools Starter Kit 115
Cleaning & Handling the Glass Panel 116
Do’s and Don’ts 116
Handling a Broken Glass Panel 116
How to Remove a Broken Glass Panel 117
Safety 121
Logic Board Handling 122
Note About Images in This Guide 122
Access Door 123
Memory 125
Glass Panel 127
Removal 128
Reassembly 129
LCD Panel 132
Handling LCD Panel 136
DisplayPort Cable 138
Vertical Sync (V-Sync) Cable 140
LCD Temp Sensor Cable 141
Bluetooth Board 142
Bluetooth Antenna 144
Camera 146
AirPort Antenna 149
AirPort Card 151
LED Backlight Board 153
Power Supply 155
Backlight Pressure Wall 157
Power Supply Pressure Wall 159
Hard Drive 161
Hard Drive Sensor Cable 164
Bluetooth/Camera/Sensor Cable 166
Optical Drive 170
Optical Drive Sensor Cable 172
Optical Drive Fan 173
SD Card Reader 175
SD Card Reader Cable 178
IR Board & Cable 180
Logic Board 182
Video Card 189
Video Card Bracket 191
Battery 193
Audio Cable 195
Hard Drive Data Cable 198
Optical Drive Data Cable 201
Cable, AC/DC/SATA/Backlight Power 203
CPU Fan 204
Left Speaker 207
Right Speaker 209
Hard Drive Fan 211
Optical Drive Pressure Wall 213
Mechanism Cover 215
Stand 217
Mechanism 219
Rear Housing 221
Views
Exploded Views 225
iMac (21.5-inch, Mid 2010), Part 1 225
iMac (21.5-inch, Mid 2010), Part 2 226
iMac (21.5-inch, Mid 2010), Part 3 227
Screw Chart 228
External Views 230
Front View 230
Rear View 231
I/O Ports 232
Internal Views 233
Photo of Components below LCD 233
Photo of Components below Logic Board 234
Logic Board, Front Side 235
Logic Board, Back Side 235
Apple Technician Guide
About This Guide
iMac (21.5-inch, Mid 2010)
© 2010 Apple Inc. All rights reserved.
Updates
Updated 3 September 2010
Basics:
• Overview: New Accessories: Magic Trackpad and Apple Battery Charger: Added links to the
User Guides.
Troubleshooting:
• Display: several symptoms: Modied steps to allow unit to warm up for about a minute
(instead of 15 minutes) before evaluating front-of-screen performance.
Take Apart:
• LCD Panel: Added note that overtightening screws could lead to issue of light leakage after
unit is reassembled.
• Camera and Rear Housing: Added note that white thermal paste intended for camera
should not be used for any other purpose (such as portable computer heatsinks).
Views:
• Screw Chart: Added image for screw 922-7018.
Apple Technician Guide introduced 27 July 2010
Feedback
We want your feedback to help improve this and future Technician Guides!
Please email any comments to: smfeedback6@apple.com
2010-09-03
iMac (21.5-inch, Mid 2010) — Updates 9
Apple Technician Guide
Basics
iMac (21.5-inch, Mid 2010)
© 2010 Apple Inc. All rights reserved.
Overview
2010-09-03
The iMac (21.5-inch, Mid 2010) has an all-aluminum enclosure with a glass front which extends
all the way to the top, left and right edges. Its external appearance is identical to the previous
model, iMac (21.5-inch, Late 2009), but includes new options such as faster Intel Core i3 and i5
processors with speeds up to 3.6GHz, better graphics, and an additional input device option,
the Apple Magic Trackpad.
The Mid 2010 model can be most easily distinguished from the Late 2009 model by the internal
position of the AirPort card, which now connects directly to the logic board in the center of the
unit.
iMac (21.5-inch, Mid 2010) Basics — Overview 11
Identifying Features
The iMac (21.5-inch, Mid 2010) features include:
• Built-in 21.5-inch (viewable) LED-backlit glossy widescreen TFT active-matrix liquid crystal
display with IPS technology; 1920 by 1080 pixel resolution
• Processor and memory:
• 3.06GHz Intel Core i3 with 4MB level 3 cache
• 3.2GHz Intel Core i3 with 4MB level 3 cache
• 3.6GHz Intel Core i5 with 4MB level 3 cache (CTO)
• 4GB (two 2GB SO-DIMMs) of 1333MHz DDR3 SDRAM; four SO-DIMM slots support up to
16GB maximum
• Graphics and video support:
• ATI Radeon HD 4670 with 256MB of GDDR3 memory
• ATI Radeon HD 5670 with 512MB of GDDR3 memory
• Mini DisplayPort output with support for DVI, VGA, and dual-link DVI (adapters sold
separately)
• 500GB, 1TB, or 2TB 7200-rpm Serial ATA hard drive
• SDXC (Secure Digital Extended Capacity) card slot; supports higher card capacity, 32GB-2TB
• Ships with and requires at least Mac OS 10.6.3
• Apple Magic Mouse (2010) and Apple Wireless Keyboard (2009) standard with all
congurations
• Apple Magic Trackpad (CTO)
• Apple Battery Charger (CTO)
Product Congurations
For product congurations, refer to AppleCare Tech Specs: http://support.apple.com/specs/
2010-09-03
iMac (21.5-inch, Mid 2010) Basics — Overview 12
Safety Precautions
Warning: HIGH VOLTAGE: The AC/DC power supply PCB remains powered up whenever
system is plugged in, whether or not system has been turned on. Use extreme caution
when troubleshooting system with the glass panel removed.
Important: If computer is shut down by removing power cord, allow power supply a good 2-3
minutes to discharge capacitors before handling it. However, if you select “Shut Down” via the
Apple menu, the computer will discharge power supply capacitor almost immediately.
2010-09-03
iMac (21.5-inch, Mid 2010) Basics — Safety Precautions 13
Serial Number Location
The iMac (21.5-inch, Mid 2010)’s serial number is located on the bottom of the stand. When
replacing a stand, transfer the serial number to the new stand.
2010-09-03
iMac (21.5-inch, Mid 2010) Basics — Serial Number Location 14
New Accessories
Magic Trackpad
The wireless Magic Trackpad uses Bluetooth technology to connect to the Mac and comes with
two AA batteries installed. To use the Magic Trackpad and its full features, update your Mac to
Mac OS X version 10.6.4 or later, and then install the latest trackpad software using Software
Update, if needed. For more information, refer to the Magic Trackpad User Guide.
Note: If the iMac (21.5-inch, Mid 2010) has had system software reinstalled for any reason, pair
the Magic Trackpad and then run Software Update. If only basic functionality is present on
Magic Trackpad, ensure that it is paired correctly before launching Software Update. For more
information, refer to:
• kBase #HT4254: About Magic Trackpad and Multi-Touch Trackpad Update 1.0
• kBase #HT4273: About Magic Trackpad Update 1.0 for Windows
About the Indicator Light
The indicator light displays the status of your Magic Trackpad and the batteries.
• When you rst turn your trackpad on, the indicator light glows steadily for 2 to 3 seconds,
indicating the batteries are good.
• If your trackpad isn’t paired with a Mac, the light blinks, indicating your trackpad is in
discovery mode and ready to pair (pairing means connecting your trackpad and Mac to
each other wirelessly).
• If you don’t pair your trackpad with your Mac within 3 minutes, the light and trackpad turn
o to conserve battery life. Press the on/o button on your trackpad to turn it on again,
allowing you to pair it with your Mac.
• When your trackpad is on and connected, the indicator light turns o.
2010-09-03
Turn on the Trackpad
• To turn the trackpad on, press rmly and release the on/o button.
• To turn the trackpad on and make it stay in discovery mode (prevent auto-pairing to
previous known host), press and hold the on/o button.
iMac (21.5-inch, Mid 2010) Basics — New Accessories 15
Pairing the Magic Trackpad
To pair your trackpad:
1. Choose Apple () menu > System Preferences, and then click Trackpad.
2. Click “Set Up Bluetooth Trackpad …” in the lower-right corner.
3. Press the on/o button on your trackpad to turn it on.
4. Click Continue when your trackpad is detected.
Once your trackpad is paired with your Mac, use Software Update again to make sure you have
the latest software installed.
Note: If the iMac (21.5-inch, Mid 2010) has had system software reinstalled for any reason, pair
the Magic Trackpad and then run Software Update. If only basic functionality is present on
Magic Trackpad, ensure that it is paired correctly before launching Software Update.
Installing Batteries
1. Use a coin to remove the battery compartment cover on the left side.
2. Insert batteries into the battery compartment as shown.
Warning: Replace or recharge batteries at the same time. Don’t mix old batteries with new
batteries and don’t mix battery types (for example, alkaline and lithium batteries). Don’t open
or puncture the batteries, install them backwards, or expose them to re, high temperatures, or
water. Don’t charge nonrechargeable AA batteries. Keep batteries out of the reach of children.
2010-09-03
iMac (21.5-inch, Mid 2010) Basics — New Accessories 16
Apple Battery Charger
Use the Apple Battery Charger to charge rechargeable NiMH batteries for your Apple products
that use AA batteries. Each Apple Battery Charger comes with six high-performance AA NiMH
batteries: two for your keyboard, two for your mouse or trackpad, and two for charging. You
can use the Apple Battery Charger to charge either one or two NiMH rechargeable batteries. To
charge batteries fully, allow at least ve hours of charging time. For more information, refer to
the Battery Charger User Guide or kBase #HT4275: About Apple Battery Charger.
Batteries
Use only NiMH rechargeable batteries in the Apple Battery Charger. Don’t try to charge
nonrechargeable AA batteries (lithium or alkaline) in the charger.
Caution: Risk of explosion if battery is replaced by an incorrect type. Dispose of used batteries
according to the instructions. Don’t open or puncture the batteries, install them backwards,
short circuit, or expose them to re, high temperatures, or water. Keep batteries out of the reach
of children.
Status Lights
The indicator light on top of the Apple Battery Charger displays the charging status of the
batteries.
• Amber: The batteries are charging.
• Green: The batteries are charged and ready to use—the green indicator light shuts o after
six hours.
• No light: May indicate any of the following conditions:
• The batteries are charged and ready to use.
• The inserted batteries are too deeply discharged to register immediately.
• Flashing Amber: May indicate any of the following conditions:
• The batteries haven’t been properly installed in the charger.
• An unsupported type of battery is in the charger.
• The batteries may be faulty or damaged and should be replaced.
2010-09-03
iMac (21.5-inch, Mid 2010) Basics — New Accessories 17
Apple Technician Guide
Troubleshooting
iMac (21.5-inch, Mid 2010)
© 2010 Apple Inc. All rights reserved.
General Troubleshooting
Wireless Troubleshooting
If you’re having issues with Bluetooth and wireless connectivity issues, refer to:
• Bluetooth Service Diagnostic (BSD) self-paced training
• Bluetooth Troubleshooting Course
• kBase #TS3048: Troubleshooting wireless mouse and keyboard issues
• kBase #HT3887: Wireless input devices: Bluetooth frequently asked questions
• kBase #HT1365: AirPort and Bluetooth: Potential source of interference
• kBase #HT3903: Apple Wireless Keyboard and Mouse: How to install batteries
• kBase #HT4275: About Apple Battery Charger
• kBase #HT4254: About Magic Trackpad and Multi-Touch Trackpad Update 1.0
• kBase #HT4273: About Magic Trackpad Update 1.0 for Windows
Update System Software & Firmware
Important: Ensure the correct version Mac OS X and latest software and rmware updates have
been applied before you begin troubleshooting. Computers sometimes exhibit symptoms that
indicate the wrong Mac OS X system software is installed.
Firmware is the name given to software that is written into memory circuits such as ash
memory, that will hold the software code indenitely, even when power is removed from
the hardware. Firmware on Intel Mac computers is designed to be updated if necessary by
running the Mac OS X Software Update check (available in the Apple menu) while computer is
connected to the Internet. For more information about rmware updates, refer to:
kBase # HT1557: About rmware updates for Intel-based Macs
Troubleshooting Theory
For general information on troubleshooting theory, go to GSX and nd the Service Training
course 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 X
For 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 updates
kBase #HT2956: Troubleshooting Mac OS X installation from CD or DVD
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 19
Common Reset Procedures
Power On Self Test (POST)
Intel-based Mac computers such as the iMac rely on a combination of tones and blinking LEDs
to display Power On Self Test (POST) error codes.
• If the computer detects out-of-specication or no SDRAM, the screen will remain black
but the computer will beep. This error condition may be due to physically damaged RAM,
installing an incorrect type of RAM, or not having RAM installed.
• Some RAM may appear to pass the Power-On-Self-Test (POST) but still cannot be used by
the operating system. In this case, the computer will display a gray screen, sound three
tones and repeat tones until computer is turned o.
• The solution to both of these situations is to rst re-seat memory and test computer again.
If memory fails the POST test again, remove all installed memory and test by installing one
by one each memory module that has been veried to work correctly on another system
(i.e., “known-good” memory) or order new memory.
• A sequence of tones heard at startup or a no video symptom may also be xed by
temporarily removing/replacing the backup battery.
For more information, refer to:
kBase #HT2538: iMac (Mid 2007) and later models: About new startup tones
Resetting the System Management Controller (SMC)
The System Management Controller (SMC) is a chip on logic board that controls all power
functions. If computer is experiencing any power issue, such as not starting up, not displaying
video, sleep issues, or fan noise issues, resetting SMC may resolve it. To reset SMC on an iMac:
1. From Apple menu, choose Shut Down (or if the computer is not responding, hold power
button for approximately ten seconds until it powers o).
2. Unplug all cables from computer, including power cord.
3. Press and hold the power button for 5 seconds.
4. Release the power button.
5. 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 a
mode 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
6. 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)
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 20
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 of
computer 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 PRAM
kBase #HT1379: Resetting your Mac’s PRAM and NVRAM
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 on
the 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 normal
startup. 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
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 21
Removing the Battery, Measuring DC Voltage
1. Shut down and unplug the computer. Allow several minutes for power supply to discharge.
2. Remove logic board.
3. Remove coin battery for 1-2 minutes. The coin battery is located on the back side of the
logic board (see graphic below).
4. Measure DC voltage on battery touching battery with red probe, and grounding with black
probe. If voltage is 2.7v or less, replace battery.
5. Reinstall the battery and logic board. This will reset the logic board.
6. Power on computer.
7. If computer boots, check for and install all software and rmware updates.
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 22
Diagnostics
Run latest available service utilities to determine if any thermal sensors or blowers are
malfunctioning. When a test reports an error, reseat appropriate connections and check that
all air ows are free from obstruction. If issue persists, replace the corresponding part (sensor,
blower, logic board, video card, or power supply). See chart below for correlation between
aected sensor, sensor location, and additional checks to perform.
Note: AHT can be run by pressing the D key on startup (if hard drive was not reformatted, or if
adequate system specic restore DVD is inserted). If a sensor error is detected, AHT will report
an error code containing the aected sensor name (ex: “4SNS/1/40000000 TC0H” error code
reports to sensor TC0H).
Sensor Suspected part and Location Suggested Action Notes
TA0P Excessive incoming ambient
air temperature, or ambient
temp sensor (part of CPU
fan assembly) is damaged/
disconnected from logic
board.
T00p Excessive optical drive
area temperature, or ODD
temp sensor damaged/
disconnected from logic
board.
TH00 Excessive hard drive area
temperature, or HD temp
sensor damaged/disconnected
from logic board. Use the
correct sensor cable, each
drive vendor has a unique
sensor cable model.
Tm0p Excessive logic board
temperature (this sensor is
part of logic board)
TL0p Excessive LCD panel area
temperature, or LCD temp
sensor damaged/disconnected
from top of logic board
Verify that incoming/outgoing
air vents are free from
obstruction , that CPU fan
cable is securely connected
to the left edge of the logic
board. Replace fan/sensor
assembly if damaged.
Verify sensor cable is securely
connected to the logic
board and the sensor is
properly attached to the ODD
mechanism. Replace sensor
cable if damaged.
Verify sensor cable is securely
connected to top side of
logic board, and is correctly
connected and oriented to
the hard drive end. Check for
damaged cable or logic board.
Test with known-good logic
board
Verify that the LCD sensor
cable is securely connected
to the logic board and the
sensor is covered by a foam
gasket on the LCD.
All fans ramp
at full speed if
fan/sensor is
disconnected.
The ODD fan
will run at full
speed if sensor
is disconnected.
The HD fan may
run at full speed
if the sensor is
disconnected/
misconnected.
The CPU fan will
run at full speed
if the sensor is
disconnected.
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 23
TS2P Excessive upper internal
enclosure temperature, or
Bluetooth/camera/sensor
damaged/disconnected from
top of logic board.
TC0H Excessive processor heatsink
temperature, or CPU temp
sensor damaged/disconnected
from logic board (this sensor is
part of logic board)
TG0D Excessive graphics processor
die temperature (sensor is part
of graphics processor chip)
TG0H Excessive graphics processor
heatsink temperature, or
GPU temp sensor damaged/
disconnected from back side
of logic board (this sensor is
part of video card assembly)
Tp1P,
Tp2H,
Tp3H
Excessive power supply
temperature (these sensors
are part of the power supply)
ODD fan Optical fan located next to
right speaker
HDD fan Hard drive fan, located below
logic board, near hard drive
CPU fan CPU fan, located next to left
speaker.
Verify that the Bluetooth/
camera/sensor cable is
securely connected to the top
of the logic board. Replace
the cable if damaged.
Check CPU sensor cable
connection to logic board. It
is located on back side and
requires removal of the logic
board.
Test with known-good video
card
Check GPU sensor cable
connection to logic board.
(requires removal of the logic
board to access).
Test with known-good power
cable harness , or knowngood power supply board.
Verify that the ODD fan
cable is securely connected
to the right side of the logic
board and that there are
no obstructions that would
prevent the fan from rotating.
Replace fan if error continues.
Verify that the HDD fan cable
is securely connected to the
top of the logic board and
that there are no obstructions
that would prevent the fan
from rotating. Replace fan if
the error continues.
Verify that CPU fan/ambient
sensor cable is securely
connected to the left side
of the logic board and that
there are no obstructions
that would prevent the fan
from rotating. Replace fan
assembly if the error persists.
If the sensor is
disconnected,
the CPU fan
will run at full
speed.
If sensor is
disconnected
the ODD fan
will run at full
speed.
Normal fan
operation,
except the ODD
blower
Normal fan
operation,
except the HDD
blower
Normal fan
operation,
except the CPU
blower
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 24
Sensor and Fan Connector Locations
Temp sensors and fan connector locations are shown below. Ensure cables are correctly routed
and the sensors and fans are properly connected. If a sensor or fan is faulty or not connected,
Apple Hardware Test or Macintosh Resource Inspector diagnostics will generate an error code.
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 25
Diagnostic LEDs
There are four built-in diagnostic LEDs on the logic board that can help troubleshoot the
computer. LEDs are located on the front center of the logic board, above the IR board, to the
left of the SMC reset button.
LED Functions
LED #1
• Indicates that the trickle voltage from power supply has been detected by main logic board.
This LED will turn ON when you connect the iMac to a working AC power source. The LED
will remain ON as long as the computer is ON or asleep.
• When computer has been correctly shutdown, the LED#1 behavior may dier:
• - If a startup event is scheduled in System Preferences/Energy saver, LED#1 will stay ON after
a correct shutdown,
• - If no startup event is scheduled in System Preferences/Energy saver, LED#1 will turn OFF
and will stay OFF as long as AC cable is kept connected and AC power source is present.
Disconnecting the AC cable and plugging it back will turn back this LED ON , even if
computer is still o.
• After disconnecting and reconnecting the AC power source, this LED could remain OFF if
the AC power source is missing or disconnected , if the logic board is disconnected from
the power supply or from the AC receptacle, or if the power supply board is faulty.
LED #2
• Indicates that computer is turned on. This LED will be ON as long as computer is turned on
(but is not asleep) and power supply and voltage regulators are working correctly.
LED #3
• Indicates that computer and video card are communicating. This LED will be ON when
computer is communicating properly with video card. If LEDs 1 and 2 are ON and you heard
the startup sound, but LED 3 is OFF, then the backup battery (on back of logic board) may
need to be reseated, or the video card might be installed incorrectly or needs replacement.
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 26
LED #4
• Indicates that computer and LCD panel are communicating. This LED will be ON when
computer is turned on and video signal is being generated. If LED#4 is ON and there is no
image on display, then the LCD panel, the LED backlight board, or the cables between LCD
and logic board or backlight board might be installed incorrectly, or need replacement.
LED Startup Sequence
LED #1 = Power available.
If no LED is visible:
• First disconnect the AC cable from computer, then reconnect it to reset the LED status,
in case computer was correctly shutdown and AC was kept connected since
• Verify AC source
• Verify known-good AC cable is connected
• Verify cable connection between AC inlet and power supply
• Verify cable connection between power supply and logic board
• Verify power supply
LED #1 + LED #2 = Power available, and system is powered on.
If second LED is not visible when power button is pressed:
• Verify power button connection to logic board
• Verify power button functionality
• Verify cable connection between power supply and logic board
• Verify power supply
• Verify logic board
2010-09-03
LED #1 + LED #2 + LED #3 = Power available, system is powered on, and video card found.
If third LED is not visible after power on:
• Verify that the MXM video card is seated properly
• Verify if boot chime is present and fans are running when powered ON (reset SMC and
PRAM, reseat or check backup battery if necessary for proper boot up):
If POST boot chime is not heard, go to Won’t Start Up symptom ow,
If POST boot chime is heard, go to No Video symptom ow.
LED #1 + LED #2 + LED #3 + LED #4 = Power available, system is powered on, video card
found, and internal LCD found.
If fourth LED is not visible after power on:
• Verify internal DisplayPort cable connections between LCD panel and logic board
• Inspect LCD display cables for cable damage
• Verify external video functionality, and according to result check the following items:
If external display works then verify/replace the LED backlight board
If external display works then verify/replace the LCD panel
If external display does not work verify/replace the logic board
iMac (21.5-inch, Mid 2010) — General Troubleshooting 27
Logic Board Test Points
Test points, which can be used to verify proper power ow, are accessible in center of logic
board, to right of SMC Reset button, when LCD panel is removed. All voltages given in
Troubleshooting Symptom Charts assume that computer is plugged into a known-good power
outlet with a known-good AC cable. Some guidelines for using test points:
• Warning: HIGH VOLTAGE: Use extreme caution when live testing!
• Do NOT lean over or touch the power supply area during live testing.
• Keep your ngers behind nger guards on test probes when measuring.
• Turn dial of voltmeter/multimeter to measure DC (direct current, usually indicated by a solid
horizontal line over dashes). If your voltmeter requires a set voltage range, choose a DC
range that includes the voltage you are measuring.
• Connect black probe to ground. Connect red probe to test point and verify voltage.
For more info, see kBase #HT3250: Diagnostics: Using a digital multimeter
2010-09-03
Test Point Function
Pin 1 Ground
Pin 3 5V power for Hard Drive(s). Note: If present, the 12V power will come directly
from the Power Supply to the Hard Drive thru the power harness cable.
Pin 4 Standby 12V power (permanent power coming from power supply, present as
long as AC cable is connected, even if computer is o); corresponds to LED #1
Pin 6 Backlight Control pulse width modulated signal (from logic board to LED
backlight board, to adjust the backlight level setting according to user setup)
Pin 11 12V Run-Mode power to logic board (coming from power supply, present as
long as system is on or asleep); corresponds to LED #2
Pin12 Power On Request signal (from logic board to power supply when power
button is pressed)
Pin 13 Backlight Enable (signal from logic board to Backlight Controller board, to
enable backlight
iMac (21.5-inch, Mid 2010) — General Troubleshooting 28
Block Diagram
Refer to this diagram to see how modules are interrelated.
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 29
Functional Overview
Refer to this diagram for symptoms related to logic board connectors.
To rotate this page in Preview for easier viewing, go to Tools menu and choose “Rotate Left”.
- reduced performance or system
sleep if LCD temperature gets too high
IR Receiver:
Ram:
- no boot,
- beep tones on startup,
- freezes, or kernel panics
Control + Power Supply
Temperature sensor:
- no power, no video
- no/poor backlight control
- fan runs at higher speed
- reduced performance or
system sleep if power supply
temperature gets too high
- no boot from bootable HD
- no HD visible on SATA bus
Optical Drive SATA Data +
Power:
- no boot from ODD drive
-no ODD seen on SATA bus
- ODD drive does not inject /
eject any media
high
Power Supply + Backlight
Hard Drive SATA Data :
CPU Temperature Sensor:
- fan running at higher speed,
- reduced performance or system
sleep if CPU temperature gets too
- reduced performance or system
gets over heating
sleep if CPU temperature gets too
high due to disconnnected fan/sensor
blocked fan
- no Power On (unless shorting the
pads on logic board)
startup
CPU Fan + Ambient Air
Temperature sensor:
- fan(s) running at higher speed
- system freezes or kernel panic if CPU
- no IR Remote functionality
Power On Button:
Backup Battery:
- no video
- beep sequence on
Bluetooth + Camera + Camera LED
+ Skin (enclosure) Temp Sensor:
- cannot enable Bluetooth or camera
- no LED when camera is on
- fan running at higher speed
- reduced performance or system
sleep if enclosure temperature gets too
high
LCD Temperature Sensor:
- fan running at higher speed
Hard Drive Temperature
Sensor:
- fan running at higher speed
if cable disconnected,
miscconnected, or not
matching drive brand/model
Hard Drive Fan:
- hard drive data
corruption if fan is
blocked or disconnected
Optical Drive Temperature
Sensor:
- ODD fan running at higher
- media read/burning fail if
speed
ODD temperature gets too
high
Optical Drive Fan:
- ODD temperature getting
- media read / burning fails if
too high
fan disconnected or
blocked
LCD DisplayPort:
- no video on internal LCD
- defective video on internal
Audio Board:
- no external Optical/
Analog audio input or
output
Left Speaker
- no sound from left speaker
- no SD card read
System Profiler
- no video on internal LCD and
on external DisplayPort
connector
Microphone
- no internal microphone sound
input
SD Card Reader:
- no SD card reader seen in
- distorted left sound
MXM Video Card:
Right Speaker :
- no sound from right speaker
- distorted right sound
- reduced performance or
system sleep if video card
temperature gets too high
Video Card Temperature
Sensor:
- fan running at higher speed
- video artifacts / video freezes
LCD
AirPort Card:
- cannot enable AirPort
- kernel panic (trace available in
panic.log when loading
wireless driver)
2010-09-03
iMac (21.5-inch, Mid 2010) — General Troubleshooting 30
Symptom Charts
Follow steps in the order indicated below. If an action resolves the issue, retest system to verify.
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 drive
activity
• Caps Lock LED on wired
keyboard doesn’t light when
pressed.
1. Verify power source.
2. Verify power cable.
3. Listen closely for signs of activity from system
including: rotating fans, hard drive or optical drive
activity, startup chime, etc.
Deep Dive
Check Result Action Code
1. Power ON system. Verify if
there is any indication that the
system has powered up (fan
rotation, hard drive or optical
drive noise, backlight turns on).
2. Disconnect AC cable Remove
glass and LCD panel and
locate the diagnostic LEDs
in the middle of logic board.
Reconnect AC cable to system.
Verify if diagnostic LED #1 turns
ON. You may alternately check
for presence of a 12V DC signal
between pin 4 and pin 1 of the
logic board.
Yes
No Go to step 2.
Yes Standby power voltage being
No Go to step 4.
The symptom is powering up.
Go to Won’t Start Up.
supplied by power supply.
Go to step 3.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 31
3. Press power button while
monitoring diagnostic LEDs.
Verify if LED #2 turns ON and
remains ON after releasing
the power button. You may
alternately check for a power
request signal between pin 12
and pin 1 of logic board.
Yes Power supply functioning and
logic board detects supply
voltages and is powered on.
Go to Won’t Start Up.
No Go to step 5.
4. Disconnect AC cable. Carefully
inspect the connectors
between AC inlet and power
supply, then DC connectors and
cables between power supply
and logic board, for damage or
poor connections.
5. Inspect power button and
verify if it is properly connected
to the logic board.
6. Disconnect power button from
logic board. Inspect cable and
connector for damage. Using a
multimeter (set as ohmmeter),
verify continuity between the
two pins of the power button
when it is pressed.
7. Reconnect AC cable Press
power button and Verify if
system turns ON. You may
alternately check for presence
of a 12V DC signal between
pin 11 and pin 1 of logic board
when power button is pressed.
Yes Reseat misconnected cable(s),
or replace damaged one(s).
No Replace DC power cable
harness. Go to step 8.
Yes Go to step 6.
No Reconnect power button.
Yes Power button is functioning
correctly. Reconnect power
button to logic board and
go to step 7.
No Power button faulty. Replace
rear housing (which includes
power button).
Yes
Power supply functioning. If
system still won’t boot, go to
Won’t Start Up.
No Replace DC power cable
harness. Go to step 8.
P16
X03
X14
X03
2010-09-03
8. Press power button and verify if
system turns ON.
Yes Issue solved with replaced DC
power cable harness.
No Replace power supply.
P01
Go to step 9.
9. Press power button and verify if
system turns ON.
Yes Issue solved with replaced
power supply.
No Reinstall power supply and
M01
replace logic board.
Note: If No Power symptom persists after all steps have been followed use minimum
conguration troubleshooting to proceed. Try disconnecting hard drive(s), optical drive, AirPort,
, SD card modules and Bluetooth/Camera cable to determine if one of them is preventing the
power supply from functioning.
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 32
Won’t Start Up
Quick Check
Symptoms 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 install
media for this computer, from a same-model
computer in Target Disk Mode, or from a
compatible known-good OS on an external drive.
Both AirPort and Bluetooth services are available
when booted from the Install disk.
2. Reset SMC and PRAM to clear any stored,
corrupted information.
3. Start up in Safe Mode by holding shift key down
during startup to load only required kernel
extensions and disable all startup and login
items. See kBase #HT1564: Mac OS X: What is
Safe Boot, Safe Mode?
4. If system generates error tones there may be an
issue with the SDRAM. See kBase #HT2341: Intel-
based Mac: Power On Self Test RAM error codes
5. Identifying when in the startup process the
computer hangs can help isolate the issue.
See kBase #HT2674: Intel-based Mac: Startup
sequence and error codes, symbols for
information on the Macintosh startup sequence,
and error codes and symbols used.
6. Run latest available service utilities.
Deep Dive
Check Result Action Code
1. Boot computer to Apple
Hardware Test on the internal
hard drive or an inserted Install
DVD by holding down the D
key at startup. Verify if system
boots up from any of these
volumes.
2. Remove installed SDRAM, and
test with known-good SDRAM.
Verify if computer starts up
properly now.
Yes Run the extended tests
and proceed with results. If
AHT passes or boots with a
memory error, go to step 2.
No Go to step 2.
Yes SDRAM issue. Reinstall one
of user’s SDRAM modules
and retest. Proceed one by
one to nd the faulty SDRAM
module, and replace it.
No Go to step 3.
X02
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 33
3. Wait 15 seconds after computer
was powered down then
disconnect AirPort card from
logic board. Verify if computer
starts up properly now.
Yes Go to AirPort Card Kernel
Panic.
No Go to step 4.
4. Startup with Alt key to select
and start from the Install DVD
inserted in the optical drive,
or from an external bootable
volume connected. Verify if
computer starts up properly
from alternate bootable
volume.
5. Disconnect optical drive cable
and retest. Verify if computer
starts up properly now.
6. Remove coin battery on back
of logic board (you will need to
completely remove logic board
to do this), and leave out for
approximately 1 minute. Then
reinstall battery. This will reset
logic board. Verify if computer
starts up properly now.
Yes Go to Hard Drive Not
Recognized.
No Go to step 5.
Yes Reconnect optical drive and
go to Optical Drive Not
Recognized.
No Go to step 6.
Yes Issue resolved by logic board
reset. Measure DC voltage on
battery touching battery with
red probe, and grounding
with black probe. If voltage is
2.7v or less, replace battery.
For multimeter help, see
kBase #HT3250: Diagnostics:
Using a digital multimeter.
No Replace logic board. M02
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 34
Intermittent Shutdown
Troubleshooting Shutdown Causes
Always run the latest Apple service utilities to check for any abnormal value reading from
a thermal, a voltage, or a current sensor, or from a fan speed meter. The log les may also
report the cause of a previous shut down(s). Collect all available info from user on shut down
occurrence details: periodicity, power state when issue happens, running applications, running
time before shutdown. Shutdown events have four dierent types of causes:
1. User-related shut downs:
A computer shut down event may be caused by user operation. Shuttting down the computer
(by selecting the Shutdown menu, by keeping pressed the Power button for at least 4 seconds,
or by programming a timed shutdown in the Energy Saver preferences) should not be
considered as a failure unless power button is defective. Suggested steps for troubleshooting:
• reset the SMC,
• check energy saver preferences settings,
• test the Power On button for a intermittent shorting issue (which would force down the
computer.).
2. Activity-related system shut downs:
The system could not succeed the standard shutdown process and had to force shutdown, or
an installed watchdog detected that an application did not respond within specied time (this
watchdog can be enabled on Mac O X Server Energy Saver preferences). These shut downs
may be linked to system settings, devices drivers, applications or operating system freezes.
Suggested steps for troubleshooting:
• check the system logs and activity monitor utility for clues on the freezing process,
• check for available software and rmware updates for installed device drivers, applications,
or operating system,
• start the system from a known-good and up-to-date bootable drive for issue reproduction.
2010-09-03
3. Power-related system shut downs:
External power source was removed. These shut downs are due to power management,
excessive thermal/voltage/current status, poor connections or defective power sources.
Suggested steps for troubleshooting:
• reset the SMC
• check secure AC cable, AC inlet and Power Supply board connections to logic board,
4.Hardware-related system shut downs:
One of the temperature, voltage or current sensors reached a specied limit. These shut downs
are due to temperature, voltage, current, fan speed or other hardware related sensor values
getting out of range. Suggested steps for troubleshooting:
• check for all sensors connections and values using Macintosh Resource Inspector and locate
sensors using the sensors table of the General Troubleshooting chapter,
• check for fan(s) operation,
• check for cleanliness of the heatsink ns and the air ows,
• check for correct seating of the heatsink on logic board and presence of thermal material.
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 35
Quick Check
Symptoms Quick Check
Intermittent Shutdown
• Powers o during startup.
• Powers o during desktop use.
• Computer restarts
spontaneously.
• Powers o when waking from
sleep.
1. Make sure that power cord is securely attached
to the back of computer, and is not hindered by a
desk or other furniture.
2. Plug computer directly into an AC outlet to test if
a surge protector or UPS is causing issue.
3. Open System Preferences > Energy Saver >
Schedule and make sure that a “Shut Down”
event is not scheduled.
4. Isolate OS by starting up from original install
media for this computer, from a same-model
computer in Target Disk Mode, or from a
compatible known-good OS on an external drive.
Both AirPort and Bluetooth services are available
when booted from the Install disk.
5. Reset SMC and PRAM to clear any stored,
corrupted information.
6. Start up in Safe Mode by holding shift key down
during startup to load only required kernel
extensions and disable all startup and login
items. See kBase #HT1564: Mac OS X: What is
Safe Boot, Safe Mode?
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 36
Deep Dive
Check Result Action Code
1. Activity related shutdowns:
Reset SMC and PRAM and
verify that shutdown issue still
happens.
2. Booting from known-good
bootable drive , verify that
shutdown issue still happens.
3. Power related shutdowns:
With known-good AC power
cord and AC outlet, Verify if
system continues to restart or
shutdown
4. Disconnect hard drive power
cable from hard drive and
startup the computer from
other bootable media (like
Install DVD, a same model
computer in Target Disk Mode,
or a compatible known-good
OS on an external drive). Verify
if system continues to restart or
shutdown.
Yes Check with known-good
bootable drive. Go to step 2.
No Shutdown cause was related
to SMC or pRAM programmed
shutdown settings or
corruption, and was resolved
by reverting them to default
settings.
Yes Go to step 3.
No Shutdown events do not
happen on known-good
OS. Reinstall Mac OS on user
hard drive, update OS with
latest version and check if any
rmware update is available.
Yes Go to step 4.
No AC power cord / outlet issue.
Issue resolved.
Yes Go to step 5.
No
Possible bad software or hard
drive. Go to Hard Drive Not
Recognized.
X03
2010-09-03
5. Inspect and reseat AC inlet
connection to power supply
(the smaller of the 2 cables
connected to power supply),
and DC power cable from
power supply to logic board.
Verify if damage is observed on
the cables or connectors.
6. Install known-good power
supply. Verify if system
continues to restart or
shutdown.
Yes Replace damaged cable.
Retest. Return to step 1 if
problem continues.
No Go to step 6.
Yes Reinstall original power
supply. Go to step 7.
No Issue resolved with power
supply replacement.
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 37
X03
P02
7. Replace DC power cable,
which supplies power to
logic board, hard drive, and
LED backlight board. Verify if
system continues to restart or
shutdown.
Yes Go to step 8.
No Issue resolved with DC power
cable replacement.
X03
8. Hardware-related shutdowns:
Run latest available Apple
service diagnostics and verify if
a sensor failure is reported.
9. Verify if a thermal sensor
or fan failure is reported by
diagnostics.
Yes -If a temperature or a fan
sensor failure is reported, go
to step 9.
-If a voltage or a current
sensor failure is reported test
with known-good power
supply board. If issue persists,
replace logic board.
No Setup ASD to loop test suite
for burn in tests and go to
step 9. If no failure is found
after burn in tests, return unit
to user for no failure found.
Yes -If fan not running failure,
check for fan cable seating
and retest. If same failure
after retest replace fan with
known-good fan and retest.
If issue does not happen with
known-good fan, replace
user’s fan.
-If an over temp failure
reported, check for cause of
over temp, like obstructed
vent, dust in heatsink n,
clogged fan and retest. If still
failing replace part where
sensor is located (logic board,
power supply, hard drive or
sensor cable) according to
the sensor location table
in General Troubleshooting
chapter. Go to step 10.
M23
X22
M23
P17
X03
2010-09-03
10. Isolate if issue solved
Verify if shutdown/issue does
is xed.
No Go to step 10.
Yes Issue resolved.
No Replace logic board with
corresponding symptom:
-if for thermal error cause
-if for other cause
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 38
M18
M08
Kernel Panic, System Crashes
Quick Check
Symptoms Quick Check
Kernel Panic, System Crashes
• Kernel Panic on startup or
desktop use.
• System freeze during use.
• System freeze upon wake from
sleep.
1. Isolate OS by starting up from original install
media for this computer, from a same model
computer in Target Disk Mode, or from a
compatible known-good OS on an external drive.
Both AirPort and Bluetooth services are available
when booted from the Install disk.
2. Ensure that all software and rmware updates for
this model have been installed to take advantage
of any available bug xes.
3. Reset SMC and pRAM to clear any stored,
corrupted information.
4. Start up in Safe Mode by holding shift key down
during startup to load only required kernel
extensions and disable all startup and login
items. See kBase #HT1564: Mac OS X: What is
Safe Boot, Safe Mode?
5. Check the panic.log, located /Library/Logs/
Panicreporter, for information in the back trace
that may give clues about the kernel panic.
6. For more information, see kBase #HT1392:
About “You need to restart your computer”
(kernel panic) messages.
2010-09-03
Deep Dive
Check Result Action Code
1. Boot the computer to Apple
Hardware Test on internal hard
drive or an inserted Install DVD
by holding down the D key at
startup. Verify if system boots
up from any of these volumes.
2. Remove all peripheral devices
including keyboard and mouse.
Verify if system starts without
kernel panic.
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 39
Yes Run extended tests and
proceed with results. If AHT
passes or boots with a kernel
panic, go to step 2.
No Go to step 2.
Yes Add peripheral devices one
at a time until kernel panic
repeats. Replace device
causing issue.
No Go to step 3.
3. Use known-good SDRAM in the
system. Verify if system start
without kernel panic now.
Yes Install user’s SDRAM one by
one and retest. If kernel panic
repeats, replace aected
SDRAM. Verify if correct
SDRAM specication is being
used.
No Go to step 4.
X01
4. Wait for 20 seconds after
shutdown and disconnect
AirPort card from logic board.
Verify if system starts without
kernel panic now.
5. Disconnect SATA cable from
hard drive and startup to the
Install DVD in the optical drive
or from an external volume.
Verify if system starts without
kernel panic now.
6. Disconnect Bluetooth/Camera
cable and microphone cable
from logic board. Verify if
system starts without kernel
panic now.
7. Disconnect SD board cable on
logic board. Verify if system
starts without kernel panic
now.
8. Disconnect optical drive and
test. Verify if system starts
without kernel panic now.
Yes Go to AirPort Card Kernel
Panic.
No Go to step 5.
Yes Go to Hard Drive Not
Recognized.
No Go to step 6.
Yes Go to Bluetooth issues,
Camera Issues or Audio:
Microphone symptom ow
as appropriate.
No Go to step 7.
Yes
Go to SD Card Not
Recognized.
No Go to step 8
Yes Go to Optical Drive Not
Recognized.
No Replace logic board. M06
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 40
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 external display
to Verify if iMac video circuitry is functioning.
If image appears on external display go to
Backlight Issue/No Backlight.
3. Reset SMC.
Deep Dive
Check Result Action Code
1. Verify boot chime present and
fans running when system
powered ON. (Reset SMC and
clear PRAM, reseat Backup
Battery on logic board if
necessary and retest for proper
boot up.)
2. Verify if image is visible on
built-in LCD panel.
Yes Power ON self test OK. Boot
sequence started.
Go to step 2.
No Go to Won’t Start Up.
Yes Video present. Verify system
functionality and return to
user or jump to appropriate
troubleshooting ow.
2010-09-03
3. Connect supported external
display. Verify if image appears
on external display when
system is booted.
No Go to step 3.
Yes External display detected by
system. Video circuitry on
logic board functional.
Inspect DisplayPort cable to
back of panel connection.
Reseat and test again. If you
continue to have problems
go to Backlight Issue/No
Backlight.
No Go to step 4.
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 41
4. Disconnect AC, remove glass
and LCD panel to access
diagnostic LEDs on center of
logic board. Reconnect AC and
verify if LED #3 turns on shortly
after system powers on.
Yes Logic board communicating
with video card. Go to step 5.
No If LED #3 does not turn ON
reseat video card and retest,
then replace video card and
repeat step 4. If issue persists,
replace logic board.
M03
M03
5. Locate diagnostic LEDs on
logic board and verify if LED #4
turns on shortly after system
powers on.
6. Locate diagnostic LEDs on the
logic board and verify if LED #4
turns on shortly after system
powers on.
Yes Logic board communicating
with LCD panel. Go to
Backlight Issue/No
Backlight.
No Replace DisplayPort cable.
Go to step 6.
Yes Video controller functional
and communicating with LCD
panel. Go to Backlight Issue/
No Backlight.
No Video controller unable to
communicate with LCD panel.
Reseat cables rst. If issue
persists, replace LCD panel.
Retest.
X03
L03
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 42
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. Verify Mac OS X version installed is the build
number supported for the hardware. Make sure
user didn’t migrate over an old version.
Refer to kBase #HT1159: “Mac OS X versions
(builds) included with Intel-based Macs“
2. Set System Preferences > Displays to native
resolution of LCD. Non-native resolutions are
unable to produce optimal clarity.
3. Clean outside surface of glass panel.
4. Make sure all relevant rmware and software
updates have been applied. Graphics driver
updates may be included with software updates.
5. Boot from install DVD or another known-good
volume to determine whether a potential
software/driver issue exists.
6. When issue occurs, take a screenshot of the
display (Command-Shift-3). View screenshot le
on a known-good computer. If image corruption
can be seen in the screenshot then issue is with
the video drivers, software, or video/logic board.
If issue cannot be seen in the screenshot then
LCD panel and DisplayPort cable should be tested
further.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 43
Deep Dive
Check Result Action Code
1. Boot from Install DVD and
Verify if issue is still visible.
2. Verify if issue is visible on an
external display.
3. Remove video card, inspect
connector for damage or
corrosion. Reinstall video card
and retest. Verify if issue still
occurs.
4. Verify if video corruption issue
is still present.
Yes Go to step 2.
No Issue likely caused by
software or driver issue.
Troubleshoot for software
issues. Make sure all software
and rmware updates have
been installed.
Yes Issue is NOT caused by
internal LCD display.
Go to step 3.
No Go to step 6.
Yes Replace video card.
Go to step 4.
No Issue resolved by reseating
video card.
Yes Replace logic board. If a video
card was replaced, reinstall
the user’s original video card.
Go to step 5.
M04
M04
5. Verify if video corruption issue
is still present with replacement
logic board installed.
6. Inspect glass panel. Verify if
issue is caused by condensation
or contaminants on inside/
outside surface of glass panel,
or on surface of LCD panel.
No Issue resolved with
replacement video card.
Yes Return to step 1 and retest.
No Issue resolved with
replacement logic board.
Yes Clean glass and/or LCD using
procedures in Glass Panel
take-apart chapter.
Identify possible sources
of contamination (nearby
cigarette/cooking smoke,
heavy airborne dust, etc.)
to prevent recurrence.
Condensation should
dissipate after computer has
been running a few hours.
No Go to step 7.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 44
7. Disconnect DisplayPort cable
between LCD display and logic
board, and verify if there is
damage to cable or connectors.
Repeat with vertical sync cable
connected between LCD panel
and LED backlight board.
Yes Replace DisplayPort cable
or any other damaged part/
module.
No Reinstall DisplayPort cable
and vertical sync cable.
Go to step 8.
X03
8. Verify if issue is still visible
after reinstalling/replacing
DisplayPort cable and vertical
sync cable.
9. Verify if issue is still visible after
replacing DisplayPort cable or/
and vertical sync cable.
10. Verify if issue is still present
with replacement LCD panel
installed.
Yes If video corruption symptom
appears to be like a rolling
image (bad location of the
top of image), replace v-sync
cable and go to step 9.
Else replace DisplayPort cable
X03
X03
and go to step 9.
No Issue resolved with reseating/
replacing damaged cable(s).
Yes Replace LCD panel. L04
No Issue resolved with replacing
the cable(s).
Yes Contact Apple Technical
Support.
No Run Apple Service Display
L04
Utility Diagnostic and enter
the receipt code in the “Repair
Notes” section. Issue resolved
with replacement of LCD
panel.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 45
Burnt Smell/Odor
Unlikely cause: speakers, microphone, rear housing
Quick Check
Symptoms Quick Check
Burnt Smell/Odor
• Burning smell
• Unusual odor
1. Verify that computer is the source of the odor.
2. If system is new, see kBase #TA22044: “New
Equipment: Odors May Be Present Short-Term”
3. Disconnect all third-party devices and check to
see if any external device is the source of odor.
4. Inspect air intake and air outlets for obstructions.
To prevent overheating make sure there
is sucient clearance to allow air to ow
unobstructed into and out of the system.
5. Verify if system is functional.
Deep Dive
Check Result Action Code
1. Verify if source of the odor
can be identied by visually
inspecting each module
and its associated cables for
signs of burned or damaged
components, smoke residue,
burned traces, or melted or
damaged wiring,
Yes Replace aected module(s).
Go to step 2
No Unable to locate source of
odor. Go to step 3.
P08
2010-09-03
2. Disconnect all third-party
devices and cables. Power ON
system and verify if smoke or
strong odor returns.
Yes Power down system
immediately. Go to step 3.
No System functions correctly.
Verify system functionality
with third-party devices and
cables and return system
to user if problem has been
resolved. Consult third-party
companies as needed for
issues with those products.
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 46
3. Verify if source of odor can be
located using your nose.
Yes Check all AC and DC power
No Contact Apple for assistance
Uncategorized Symptoms
Quick Check
Symptoms Quick Check
P08
cables for pinch or damage.
Replace aected module(s)
and retest system.
if you feel that there is a
possible safety issue with
computer that has not been
resolved in previous steps.
Uncategorized Symptoms
• Unable to locate appropriate
symptom 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 powering
up. If noise is heard, go to Won’t Start Up. If no
noise is heard go to
No Power, Dead Unit.
3. Attempt to boot from Install DVD to isolate
possible software issues.
Deep Dive
Check Result Action Code
1. Verify if existing symptom code
applies to issue reported by
user.
Yes Jump to appropriate
symptom code ow.
No
Document reported failure
and send feedback to
smfeedback6@apple.com
stating that a suitable
symptom code wasn’t found.
Provide as much detail as
possible.
N99
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Startup and Power 47
Display
Backlight Issue/No Backlight
Unlikely cause: hard drive, optical drive, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Backlight Issue/No Backlight
• No image
• Partial backlight failure
• Backlight ickers
• Display dim
1. Check for Software Update.
2. Verify that System Preferences > Displays >
Brightness control setting is above minimum.
3. If no image on built-in display, connect external
display to verify if iMac video circuitry is
functioning. If no image visible on external
display, go to No Video.
Deep Dive
Check Result Action Code
1. Verify boot chime present and
fans running when computer
powered ON. (Reset SMC and
clear PRAM if necessary for
proper boot up.)
2. Verify if image is visible on
built-in LCD panel, with
adjustable backlight level.
Yes Power on self test OK.
Go to step 2.
No Go to Won’t Start Up.
Yes Video present. Verify system
functionality and return to
user or go to appropriate
troubleshooting ow.
No Go to step 3.
2010-09-03
3. Connect supported external
display. Verify if any image
appears on external display
after system has booted.
4. Verify if LCD backlight is ON
by looking for faint glow
from display when viewed in
darkened room with brightness
set at maximum.
Yes External display detected by
system. Video circuitry on
logic board functional.
Go to step 4.
No Go to No Video.
Yes LED backlight is functioning.
Go to step 7.
No Go to step 5.
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 48
5. Shine bright (low heat)
ashlight onto front of LCD.
With computer powered ON
verify if a faint image is visible.
Yes LCD panel functional but
backlight is missing or
dim. Remove LCD panel
and inspect and reseat the
following cable connections:
-Output cable between lower
end of LED backlight board
and lower end of LCD panel.
-Vertical sync cable between
upper end of LED backlight
board and LCD panel.
-DC power cable between
upper right of LED backlight
board and power supply.
Replace any damaged cable.
Reinstall LCD panel and go to
step 6.
No No image or backlight.
Go to step 7.
X03
6. Power ON system. Verify if
image is now visible on LCD
panel with correct backlight
level.
7. Inspect and reseat DisplayPort
cable between LCD panel and
logic board. Power ON system.
Verify if image is visible on
built-in LCD display.
Yes Issue resolved.
No Replace LED backlight board.
Retest. If issue persists, go to
step 7.
Yes Issue resolved.
No Replace DisplayPort cable.
If issue persists, replace LCD
panel. Retest.
M04
X03
L03
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 49
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 bottom of computer is
not obstructed.
2. Inspect system for third party software that is
being used to set fan speeds to a higher than
normal RPM. Some users may install this software
to monitor and control internal temperatures,
potentially causing higher fan speeds to generate
higher than expected noise levels.
Deep Dive
Check Result Action Code
1. Verify if user issue is due to
ickering, or to an unstable
video image on the LCD.
2. Connect a supported external
display to the mini DisplayPort
on rear of computer. Verify
if issue occurs with external
display.
Yes Suspected ickering issue.
Go to step 2.
No For audible noise issues go to
step 8. All other issues go to
appropriate.
Yes Suspect issue with video
circuitry. Go to Corrupted
Video.
No Video circuitry OK.
Go to step 3.
2010-09-03
3. Disconnect and carefully
inspect all four cables on
back of LCD panel for signs of
damage, corrosion, or pinched
wires.
4. Power ON computer and verify
if issue still occurs.
Yes Replace damaged cable(s)
where needed, otherwise
reattach connectors. Retest.
No Go to step 4.
Yes If connections are secure and
display is still ickering, go to
step 5.
No Issue resolved.
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 50
X03
5. Shine bright (low heat)
ashlight into front of LCD.
Verify if an image is being
displayed when ickering issue
is occurring.
Yes Image present but backlight
is ickering. Replace vertical
sync cable (between LCD
panel and upper end of LED
backlight board) and retest.
X03
If issue persists, replace LED
backlight board.
No Replace DisplayPort cable
between LCD panel and logic
board, and retest.
6. Verify if noise varies when
adjusting brightness level up
and down.
Yes Noise seems to be generated
by vertical sync cable. Inspect
and replace.
No Noise is from another source.
Go to step 7.
7. Verify if noise can be heard
when computer is set up with
Yes Replace LED backlight board.
Go to step 8.
user seated in normal user
position. Adjusting brightness
level up and down may be
necessary to recreate issue.
No Noises that are not audible
from the normal user position
are considered acceptable.
8. Verify if noise is still present. Yes Replace LCD panel. If noise
still present, go to Noise/
Hum/Vibration.
No Issue resolved.
M04
X03
M04
L06
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 51
LCD Image Issues
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
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 operating
temperature for about a minute before
evaluating front-of-screen performance.
2. Check display preferences for use of custom
display prole.
3. Check brightness setting.
4. Clean glass panel while checking for dust/debris.
Deep Dive: General
Check Result Action Code
1. Verify if issue is incorrect/
missing colors.
2. Verify if issue is distorted/
blurred image.
3. Verify if issue is bright or dark
pixel anomalies.
Yes
No Go to step 2.
Yes Go to distorted/blurred
No Go to step 3.
Yes Go to pixel anomalies.
No Go to step 4.
Go to incorrect/missing
colors.
image.
2010-09-03
4. Verify if issue is vertical or
horizontal lines.
5. Verify if issue is non-uniform
brightness.
Yes Go to vertical/horizontal
lines.
No Go to step 5.
Yes
No LCD functioning OK. Return to
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 52
Go to non-uniform
brightness.
appropriate symptom ow if
user issue is still present.
Incorrect/Missing Colors
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Incorrect/Missing Colors
• Wrong color display
• Color/contrast issues
1. Allow display to reach normal operating
temperature for about a minute before
evaluating front-of-screen performance.
2. Verify if System Preferences > Display settings are
congured to use default display prole.
3. Verify System Preferences > Universal Access >
Display “Enhance contrast”, “Use grayscale”, and
“Black on White/White on Black” settings are set
to defaults.
Deep Dive
Check Result Action Code
1. Verify computer has been
warmed up for about a minute.
2. Verify if all four cables on back
of LCD panel are secure at both
ends.
Yes Go to step 2.
No Warm up computer for about
a minute. Go to step 2.
Yes Go to step 3.
No Reseat connections, replace
damaged cable(s) if needed.
Retest.
L14
2010-09-03
3. Go to System Preferences >
Desktop & Screen Saver >
Desktop and set color to Solid
Gray Light. Verify if incorrect/
missing color issue aects
entire display.
4. Set up computer side-by-side
with a known-good, samemodel computer showing
same image. Verify if issue is
noticeably worse on display
being tested.
Yes Suspect poor video
connection. Replace
DisplayPort cable between
LCD panel and logic board.
No Go to step 4.
Yes Replace LCD panel. L02
No Small variations in color
uniformity across display are
normal and do not warrant
replacement of LCD.
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 53
L14
Distorted/Blurred Image
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Distorted/Blurred Image
• Text and graphics appear fuzzy
• Image corrupted
1. Set System Preferences > Displays to native
resolution of LCD. Non-native resolutions are
unable to produce optimal clarity.
2. Clean outside of glass panel.
3. Boot from install DVD to determine if a potential
software issue exists.
Deep Dive
Check Result Action Code
1. Boot from Install DVD and
verify if issue is still visible.
2. Verify if issue is visible on an
external display attached to
mini DisplayPort.
Yes Go to step 2.
No Issue likely caused by
software or driver issue.
Troubleshoot for software
issues. Make sure all software
updates have been installed.
Yes Issue NOT caused by internal
LCD panel. Go to step 3.
No Go to step 6.
2010-09-03
3. For systems without video card,
go to step 4. If a video card is
present, remove video card,
inspect connector for damage
or corrosion then reinstall.
Verify if issue still occurs.
4. Verify if distorted/blurred
image issue is still present.
5. Verify if issue is still present
with replacement logic board
installed.
Yes Replace video card.
Go to step 4.
No Issue likely caused by poor
video card connection.
Yes Replace logic board. For
systems with a video card,
reinstall the user’s original
video card. Go to step 5.
No Issue resolved.
Yes Return to step 1 and retest.
No Issue resolved.
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 54
M24
M04
6. Inspect glass panel. Verify if
issue is caused by condensation
or contaminants on inside
surface of glass panel.
Yes Clean glass and/or LCD using
procedures in Glass Panel
take-apart chapter.
Identify possible sources
of contamination (nearby
cigarette/cooking smoke,
heavy airborne dust, etc.)
to prevent recurrence.
Condensation should
dissipate after computer has
been running a few hours.
No Go to step 7.
7. Remove DisplayPort cable
between LCD panel and logic
board, and verify if there is
damage to cable or connectors.
8. Verify if issue is still visible after
reinstalling DisplayPort cable.
9. Verify if issue is still present
with replacement LCD panel
installed.
Yes Replace DisplayPort cable. X03
No Reinstall DisplayPort cable.
Go to step 8.
Yes Replace LCD panel.
L04
Go to step 9.
No Issue resolved.
Yes Return to step 1 and retest.
No Issue resolved.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 55
Pixel Anomalies
Unlikely cause: logic board, power supply, hard drive, optical drive, fans, speakers, camera,
microphone
Quick Check
Symptoms 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.
2. See kBase #HT1721: About LCD display pixel
anomalies.
Deep Dive
Check Result Action Code
1. Determine if “defects” are dust/
debris on surface of glass panel
or LCD.
2. Determine if bright pixel
defects exceed acceptable
number. See kBase #HT1721:
About LCD display pixel
anomalies.
3. Determine if dark pixel defects
exceed acceptable number. See
kBase #HT1721: About LCD
display pixel anomalies.
Yes Clean glass and/or LCD using
procedures in Glass Panel
take-apart chapter.
No Go to step 2.
Yes Replace LCD panel. L08
No LCD panel meets bright pixel
defect specications.
Go to step 3.
Yes Replace LCD panel. L08
No LCD panel meets dark pixel
defect specications.
Go to step 4.
2010-09-03
4. Determine if combination
of bright/dark pixel defects
exceed acceptable number. See
kBase #HT1721: About LCD
display pixel anomalies.
Yes Replace LCD panel. L08
No Explain to user that LCD
panel is operating within
specications for pixel defects.
Do NOT replace LCD panel.
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 56
Vertical/Horizontal Lines
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Vertical/Horizontal Lines
• Vertical lines
• Horizontal lines
1. Boot from install DVD to determine if potential
software issue exists.
2. Verify if issue is visible on an external display.
Deep Dive
Check Result Action Code
1. Boot from Install DVD and
verify if issue is still visible.
2. Verify if issue is visible on an
external display attached to
mini DisplayPort.
Yes Go to step 2.
No Issue likely caused by
software or driver issue.
Troubleshoot for software
issues. Make sure all software
updates have been installed.
Yes Issue NOT caused by internal
LCD. For systems with a video
card, go to step 3. For systems
without a video card, go to
step 4.
No Go to step 6.
2010-09-03
3. If a video card is present,
remove video card and inspect
connector for damage or
corrosion then reinstall. Verify if
issue still occurs.
4. For systems without video card,
horizontal lines may be related
to a failing RAM module. Verify
if video issue only happens
AFTER Apple logo and spinning
wheel appear.
5. Start with shift key down
(safe mode) to disable system
extensions. Verify if issue still
happens when booting in safe
mode.
Yes Replace video card.
Go to step 8.
No Issue likely caused by poor
video card connection.
Yes Issue only happens AFTER
Apple logo and spinning
wheel appear. Go to step 5.
No Issue present before Apple
logo and spinning wheel
appear. Go to step 8.
Yes Go to step 8.
No No video issue when booting
in safe mode. Go to step 6.
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 57
M24
6. Isolate with only one memory
module installed, then with the
other one. Test with knowngood memory. Verify if issue
only happens with specic
RAM module(s).
Yes Replace aected RAM
module.
No Go to step 7.
X02
7. Isolate with one known-good
memory module installed in
one memory slot. Repeat by
testing in other memory slots
Verify if issue only happens
with specic memory slot of
logic board.
8. Remove DisplayPort cable
between LCD panel and logic
board and verify if there is
damage to cable or connectors.
9. Verify if issue is still present
after reinstalling DisplayPort
cable.
10. Verify if issue is still present
with replacement logic board
installed.
11. Reinstall original logic board
and verify if issue is still present
with original logic board
reinstalled.
Yes Replace logic board and
M07
retest.
No Go to step 8.
Yes Replace DisplayPort cable.
X04
Go to step 9.
No Reinstall DisplayPort cable.
Go to step 9.
Yes Replace logic board. If video
M04
card was present, reinstall
original video card.
Go to step 10.
No Issue resolved.
Yes Go to step 11.
No Issue resolved.
Yes Replace LCD panel. L04
No Issue resolved. If a video card
was present, reinstall original
video card.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 58
Non-Uniform Brightness
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Non-Uniform Brightness
• Brightness not uniform
• Color not-uniform
1. Verify System Preferences > Displays > Brightness
slider is set above minimum.
2. Allow display to reach normal operating
temperature for about a minute before
evaluating front-of-screen performance.
3. Visually inspect glass panel for presence of dust,
cigarette smoke, or other contaminants. Clean
glass panel if needed.
4. Run latest available service utilities to check for
correct LCD panel temperature.
Deep Dive
Check Result Action Code
1. Determine if brightness
uniformity issue is visible after
display has warmed up for
about a minute.
2. Look at user-provided
examples showing brightness
uniformity issue. Determine if
variation in uniformity appears
excessive when compared to
another same-model computer.
Yes Go to step 2.
No Display backlight can take a
minute to stabilize. Retest. If
issue still not visible return
computer to user.
Yes Go to step 3.
No Demonstrate to user that LCD
performs similarly to another
computer of the same model.
2010-09-03
3. Remove glass panel and
loosen screws securing LCD
panel. Determine if brightness
uniformity improves.
4. Remove LCD panel, then
inspect and reseat backlight
cables. Determine if brightness
uniformity improves.
Yes Inspect for mechanical
interference with screws
or cables making contact
with back of LCD. Reseat
components & cables, retest.
No Go to step 4.
Yes One or more backlight cables
were loose.
No Replace LCD panel. L07
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 59
Cosmetic Defects
Symptoms 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 if damage was caused by user
environment, accidental damage, or abuse. If
applicable, inform user that Apple does not
warrant damage caused by accident, abuse,
misuse, ood, re, earthquake, or other external
causes. For more information, refer to:
http://www.apple.com/legal/warranty
2. For dark and bright pixel anomalies see
Pixel Anomalies.
Uncategorized Symptoms
Quick Check
Symptoms Quick Check
Uncategorized Symptoms
• Unable to locate appropriate
symptom code.
1. Make sure brightness level is set above minimum.
2. Clean glass panel to make sure external
contaminants are removed prior to evaluating
display performance.
3. Allow LCD display to warm up approximately
15 minutes before evaluating display color and
brightness uniformity performance.
Deep Dive
Check Result Action Code
1. Verify if existing symptom code
applies to issue reported by
user.
Yes Jump to appropriate
symptom code ow.
No Document reported failure
and send feedback to
smfeedback6@apple.com
stating that a suitable
symptom code wasn’t found.
Provide as much detail as
possible.
N99
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Display 60
Mass Storage
Hard Drive Not Recognized
Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Drive Not Recognized
Drive No Boot
• Flashing Question Mark
• Boots to Grey Screen
• Boots to Blue Screen
• Boots to Prohibitory Symbol
(Review kBase #HT2674: Intel-
based Mac: Startup sequence
and error codes, symbols)
1. Use a known-good mouse. A stuck mouse button
will not allow boot.
2. Boot from Install DVD. Use Disk Utility to verify
S.M.A.R.T. status of internal hard drive.
3. Use Disk Utility to repair Mac OS X on disk.
4. Verify that user’s data is backed up and that user
authorizes erasing disk and reinstalling software.
5. Use Target Disk Mode to mount user’s drive on a
known-good computer. Use Disk Utility on host
computer for Quick Checks 2 through 4.
Deep Dive
Check Result Action Code
1. Boot from Install DVD and run
Disk Utility. Verify if user’s drive
is available for Disk Utility to
repair.
2. Run Disk Utility’s “Repair
Disk” function and verify if it
completes successfully.
Yes Go to step 2.
No Go to step 5.
Yes Go to step 3.
No Go to step 4.
2010-09-03
3. Reboot computer. Verify if
system boots successfully and
that Disk Utility “Verify” function
reports no errors.
4. With user’s permission, erase
internal drive and reinstall Mac
OS. Verify if installation process
completes.
Yes Data error. Issue resolved.
No Go to step 4.
Yes Go to step 8.
No Go to step 5.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 61
5. Check that the 4 wire SATA
power cable (carrying 12v and
5v DC) is correctly connected
to the Hard Drive. Inspect
internal hard drive SATA and
power cable and connectors for
bent pins, or other damage to
the cable(s).
Yes Replace any damaged SATA
Bus or SATA Power cable. For
the internal SATA drive, the
DC power comes from the
main DC power cable harness.
Go to step 8.
No Go to step 6.
X03
6. Reseat internal hard drive
SATA data cable at logic board
and drive ends, and verify if
computer boots up successfully.
7. Test with a known-good
bootable drive. Verify if system
boots successfully and that Disk
Utility “Verify” function reports
no errors.
8. Reboot computer. Verify if
system boots successfully and
that Disk Utility “Verify” function
reports no errors.
Yes Go to step 8.
No Replace hard drive SATA
cable. Go to step 8.
Yes Reinstall user’s drive.
Go to step 9.
No SATA data cable was veried
or replaced, and known-good
drive is installed:
-If hard drive does not spin up
when system is powered on,
replace DC power harness; if
the no spinning issue persists
after DC cable was replaced,
replace Power Supply.
-If hard drive spin up sound
can be heard when system
is powered on, but system
cannot boot from it , replace
logic board.
Yes Issue resolved. Return system
to user.
No Go to step 7.
X03
X03
P99
M19
2010-09-03
9. Reboot computer. Verify if
system boots successfully and
that Disk Utility “Verify” function
reports no errors.
10. Replace aected internal drive.
Boot from system-specic
Install DVD and reinstall Mac
OS X with drive format option.
Verify if drive is formatted
correctly (GUID partition table)
and that software restore was
successful.
Yes Issue resolved.
No User’s hard drive appears to
be defective. Go to step 10.
Yes Issue resolved by replacing
H01
aected internal drive.
No SATA data cable veried/
replaced and new drive
installed, Check with knowngood restore DVD. If restore
failure still happens, go to
step 11.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 62
11. If restore from Install DVD is
unsuccessful, startup a knowngood Intel Mac system with
T key pressed (to enter Target
Disk Mode), insert the iMac
Install DVD in its optical drive
and connect it to the user’s
system via a FireWire cable.
Startup user’s system while
holding Option key, then select
and boot from the Install
Disc DVD and restore system
software. Verify if software
restore was successful.
Yes Restore failure seems to be
due to user’s internal optical
drive or media issue. Go to
Optical Drive Read/Write
Error.
No Restore failure seems to be
due to internal SATA bus
issue. Replace logic board.
Hard Drive Read/Write Errors
Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
M19
Drive Read/Write Error
Drive Bad Sector/Defective
Drive Formatting Issues
• Cannot save documents
• Read/write error message
• Hang when accessing or saving
data
1. Boot from Install DVD. Use Disk Utility to verify
S.M.A.R.T. status of internal hard drive.
2. Use Disk Utility to repair internal hard disk.
3. Verify that user’s data is backed up and that user
authorizes erasing disk and reinstalling software.
4. Use Target Disk Mode to mount user’s drive on a
known-good computer. Use Disk Utility on host
computer for Quick Checks 2 through 3.
Deep Dive
Check Result Action Code
1. Run Disk Utility ‘Repair Disk’
function, and verify if it
completes successfully.
2. Reboot computer. Verify if
system boots successfully and
that Disk Utility “Verify” function
reports no errors.
3. With user’s permission, erase
internal drive(s) containing Mac
OS X, and reinstall it. Verify if
installation process completes.
Yes Go to step 2.
No Go to step 3.
Yes Data error. Issue resolved. H07
No Go to step 3.
Yes Go to step 6.
No Go to step 4.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 63
4. Inspect internal hard drive SATA
power and data cables and
connectors for bent pins, or
other damage to the cable.
Yes Replace damaged cable.
Go to step 6.
No Go to step 5.
H04
5. Reseat SATA cable on internal
hard drive and logic board
ends. Verify if computer starts
up.
6. Reboot computer. Verify if
system boots successfully and
Disk Utility “Verify” function
reports no errors.
7. Test with known-good
bootable drive. Verify if system
boots successfully and Disk
Utility “Verify” function reports
no errors.
8. Reboot computer. Verify if
system boots successfully and
that Disk Utility “Verify” function
reports no errors.
9. Replace user’s drive. Verify if
drive formats correctly with a
GUID partition map and installs
Mac OS without errors.
Yes Go to step 6.
No Replace internal hard drive
SATA data cable. Go to step 6.
Yes Issue resolved.
No Go to step 7.
Yes Reinstall user’s drive, go to
step 8.
No SATA data cable veried or
replaced and known-good
drive installed used without
success. Replace logic board.
Yes Issue resolved.
No User’s drive appears to be
defective. Go to step 9.
Yes Issue resolved by replacing
user’s drive.
No SATA data cable veried or
replaced and new drive did
not resolve issue. Replace
logic board.
H04
M19
H03
M19
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 64
Hard Drive Noisy
Unlikely cause: LCD panel, logic board, power supply, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Hard Drive Noisy
• Noise during start up
• Noise during operation
• Noise when drive is copying or
saving data
1. Boot from Install DVD. Use Disk Utility to verify
S.M.A.R.T. status of hard drive.
2. Use Disk Utility to repair disk.
3. Determine if noise is comparable to another
machine of the same model. See kBase #TS3204:
iMac (Late 2009) Evaluating normal noises.
Deep Dive
Check Result Action Code
1. Boot from the Install DVD and
run Disk Utility. Verify if user
hard drive is available for Disk
Utility to repair.
2. Run Disk Utility ‘Repair Disk’
function and verify if it
completes successfully.
3. Restart the computer. Verify if
the noise is still present.
Yes Go to step 2.
No
Yes Go to step 3.
No Go to step 4.
Yes Go to step 4.
No Issue resolved. Return system
Go to Hard Drive Not
Recognized.
to user.
2010-09-03
4. Remove glass and LCD panel,
check that internal hard drive
thermal sensor cable is present,
is the correct type for the
installed drive model, is well
connected and retest (with an
external display connected).
Verify if the noise comes from
the center fan.
5. Disconnect internal hard drive
SATA data cable and retest
(with an external display
connected). Verify if the noise is
still present.
Yes Replace thermal sensor cable
with correct part number (see
Exploded View to identify
the part number, and Take
Apart chapter for correct
installation).
No Go to step 5.
Yes
No Go to step 6.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 65
Noise issue still present, but
does not appear to be caused
by hard drive. Go to Noise/
Hum/Vibration.
6. Remove hard drive and verify
if rubber vibration isolation
grommets are properly
installed in hard drive bracket
(attached to hard drive) and
to mechanism in rear housing
(where hard drive pins insert).
Yes Go to step 7
No If grommets are missing or
damaged, replace hard drive
bracket or mechanism as
appropriate. Go to step 7
7. Restart system and verify if the
noise is still present.
8. Reconnect user’s drive and,
with user’s permission, erase
hard drive and reinstall Mac
OS. Verify if installation process
completes.
9. Restart system and verify if the
noise is still present.
10. With replacement hard drive
installed, reboot computer.
Verify if noise is still present.
11. Disconnect hard drive SATA and
power connections then boot
from the Install DVD. Verify if
noise is caused by fans.
Yes Go to step 8
No Reseating or replacing the
drive rubber grommets /
bracket solved noise issue.
Yes Go to step 9.
No Replace hard drive.
Go to step 10.
Yes Replace hard drive.
Go to step 10.
No Software related issue.
Yes Replacement hard drive did
not resolve issue. Go to step
11 to check for other source
of noise.
No Issue resolved by replacing
hard drive.
Yes Go to Fan Failures/Thermal
Issues.
No Go to step 12.
H06
2010-09-03
12. Disconnect hard drive and
optical drive then boot from an
external volume. Verify if noise
disappears when optical drive
has been disconnected.
Yes Possible optical drive or
media issue. Go to Optical
Drive Noisy.
No
Noise issue still present, but
does not appear to be caused
by hard drive. Go to Noise/
Hum/Vibration.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 66
Optical Drive Not Recognized
Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Drive Not Recognized/Mount
• Discs inject and eject, but do
not appear in Finder
1. Check Finder Preferences and make sure “CD’s,
DVD’s and iPods” is checked under “Show these
items on the desktop” in the General section.
2. Check aected optical media for presence of
physical damage(s) on its surface.
3. Test with known-good optical media.
4. Use System Proler Serial-ATA section to see if
optical drive appears.
5. Check System Proler Serial-ATA section for
presence of an inserted optical media.
Deep Dive
Check Result Action Code
1. Verify if optical drive is listed
in Serial-ATA section of System
Proler.
2. Test both CD and DVD media.
Verify if optical drive can read
both CD and DVD media.
Yes Go to step 2.
No Go to step 3.
Yes No issue, or possible
intermittent issue. Gather
more information from user.
2010-09-03
3. Connect known-good optical
drive to SATA cable. Verify if
both CD and DVD media are
read reliably.
No If both types of media fail,
check that Finder Preferences
are set to “show CD’s and
DVD’s”, then go to step 3.
If only one type of media fails,
drive has a laser pickup issue.
Replace optical drive.
Yes SATA cable and port on logic
board appear good. Go to
step 5.
No Go to step 4.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 67
J03
4. Reseat SATA cable connections
at optical drive and logic board
(cable connects to back of logic
board). Verify if both CD and
DVD media are read reliably.
Yes Go to step 6.
No Replace optical drive SATA
cable and test.
If issue persists, replace logic
board.
Go to step 6.
X03
M19
5. Connect original optical drive
to known-good SATA cable.
Verify if both CD and DVD
media are read reliably.
6. Test read compatible knowngood CD and DVD media
(Install DVD). Verify if media is
recognized and reads reliably.
Yes SATA cable issue. Replace
SATA cable. Go to step 6.
No Replace optical drive. J03
Yes Issue resolved.
No Replace optical drive. J03
Optical Drive Won’t Accept/Eject Media
Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Drive Won’t Accept Media
Drive Won’t Eject Media
• Cannot insert a disc into drive
• Cannot eject a disc from drive
1. Check aected optical media for presence of
physical damage(s) on its surface.
2. Use System Proler Serial-ATA section to see if
optical drive appears. If not, go to Optical Drive
Not Recognized.
X03
2010-09-03
3. Restart computer and hold down mouse button
or keyboard eject key to cycle optical drive.
4. Inspect optical drive slot for obstructions
Deep Dive
Check Result Action Code
1. Verify if optical drive is listed in
System Proler device tree for
Serial-ATA devices.
Yes Optical drive communicating
with logic board. Go to step 5.
No Go to step 2.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 68
2. Verify SATA cable connections
between optical drive and logic
board. Visually inspect cables
and connectors for any debris,
damage or bent pins. Verify if
optical drive is listed in System
Proler device tree.
Yes Optical drive communicating
with logic board. Go to step 5.
No Replace damaged cables
and retest. If connections are
good and no visible cable
damage, go to step 3.
X03
3. Connect known-good optical
drive to SATA cable. Verify if
known-good optical drive is
listed in the System Proler
device tree.
4. With known-good optical drive
installed, test for media inject/
eject. Verify if drive accepts and
ejects known-good media.
5. Inspect optical drive slot during
disc insert/eject. Verify if discs
can be inserted easily and don’t
get scraped during insertion/
ejection.
6. With known-good optical
media (Install DVD), test for
media inject/eject. Verify
if drive accepts and ejects
known-good media.
Yes Go to step 4.
No Suspect bad SATA cable.
Go to step 7.
Yes Known-good optical drive
resolved inject/eject issue.
Replace optical drive.
No Go to step 7.
Yes Go to step 6.
No Verify correct optical drive
bezel alignment with
enclosure. Reseat optical drive
then retest. If issue persists,
replace optical drive.
Yes Media issue. No repair
necessary. Suggest user
investigate use of dierent
media.
No Go to step 3.
J03
J03
2010-09-03
7. Replace SATA cable then test
for media inject/eject. Verify if
drive injects and ejects knowngood media.
Yes SATA cable resolved issue.
X03
Return system to user.
No SATA cable veried or
M19
replaced, and optical drive
veried or replaced. Replace
logic board and retest.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 69
Optical Drive Read/Write Error
Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Drive Read/Write Data Error
• Errors when writing optical
media.
• Errors when reading optical
media.
• Hang when accessing or
preparing to write data.
1. Check that optical media is not physically
damaged.
2. Run latest service utilities to check for optical
drive thermal sensor.
3. Test optical media in a known-good optical drive
in the same type of computer to rule out media
issue.
4. Check with known-good discs like the Install DVD
that came with the computer.
5. For write issues, check with known-good media
that performs well in a known-good optical drive
in the same type of computer.
Deep Dive
Check Result Action Code
1. Verify if media is free to spin
without optical drive scraping
edge or surface of media.
2. Reseat optical drive in
enclosure and verify that a
media can be inserted without
being scratched
Yes Go to step 3.
No Go to step 2
Yes Go to step 3
No Replace optical drive and
retest.
J05
2010-09-03
3. Test both CD and DVD media.
Verify if drive can read both CD
and DVD media.
4. Install known-good optical
drive and verify if both CD and
DVD media are read reliably.
Yes Go to step 7.
No If both types of media fail,
check that Finder Preferences
are set to “show CD’s and
DVD’s”, then go to step 4.
If only one type of media fails,
drive has a laser pickup issue.
Replace optical drive.
Yes Both SATA cable and port on
logic board appear good. Go
to step 6.
No Go to step 5.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 70
J03
5. Continue to use known-good
optical drive. Reseat optical
drive SATA+Power cable
connection at logic board ends
(cable connects to back of logic
board). Verify if both CD and
DVD media are read reliably.
Yes Go to step 6.
No Replace SATA cable and retest.
If issue persists, replace logic
board.
Go to step 7.
X03
M19
6. Reinstall user’s optical drive
and verify if both CD and DVD
media are read reliably.
7. Test write data to compatible
CD and DVD media. Verify if
burned media is recognized
and read reliably.
Yes Go to step 7.
No Replace user’s optical drive. J03
Yes Issue resolved.
No Run ODD sensor and ODD fan
tests in ASD:
If errors found check
ODD sensor and ODD fan
connections to logic board
(read/write errors may be due
to drive getting too hot).
If no errors are found
while running latest Apple
J03
diagnostics, replace optical
drive.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 71
Optical Drive Not Performing to Specications
Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Optical Drive Not Performing to
Specications
• Read or write speeds slower
than expected
1. Test optical media in another computer of the
same type to rule out media issue.
2. For write issues, check with known-good media
that performs well in another computer and drive
of the same type.
3. Run latest service utilities to check optical drive
thermal sensor status.
Deep Dive
Check Result Action Code
1. Test both CD and DVD media.
Verify if optical drive can read
both CD and DVD media.
2. Connect known-good optical
drive to SATA cable. Verify if
both CD and DVD media are
read reliably.
Yes Go to step 5.
No If both types of media fail,
check that Finder Preferences
are set to “show CD’s and
DVD’s”, then go to step 2.
If only one type of media fails,
drive has a laser pickup issue.
Replace optical drive.
Yes SATA cable and port on logic
board good. Go to step 4.
No Go to step 3.
J03
2010-09-03
3. Reseat SATA cable connections
at optical drive and logic board
(cable connects to back of logic
board). Verify if both CD and
DVD media are read reliably.
4. Connect original optical drive
to known-good SATA cable.
Verify if both CD and DVD
media are read reliably.
5. Test write data to compatible
CD and DVD media. Verify if
burned media is recognized
and read reliably.
Yes Go to step 5.
No Replace SATA cable and test.
If issue persists, replace logic
board.
Go to step 5.
Yes SATA cable issue. Replace
SATA cable. Go to step 5.
No Replace optical drive. J03
Yes Issue resolved.
No Go to step 6.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 72
X03
M19
X03
6. Media that is out of balance
may not perform well at higher
speeds even though higher
speeds may be supported
by the optical drive. Verify if
slowing requested burn speed
allows discs to be written
reliably.
Yes Media issue. No repair
necessary.
No Go to step 7.
7. Test write data to compatible
CD and DVD media. Verify
burned media is recognized
and reads reliably.
Yes Issue resolved.
No Check ODD sensor and ODD
fan in latest service utilities:
If errors found check
ODD sensor and ODD fan
connections to logic board
(read/write errors may be due
to drive being too hot).
If no errors are found while
running diagnostics, replace
optical drive.
Optical Drive Noisy
Unlikely cause: LCD panel, power supply, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
J03
2010-09-03
Optical Drive Noisy (J04)
• Noise during boot
• Noise during operation
• Noise when drive is copying or
writing data
1. Test optical media in another computer of the
same type to rule out media issue.
2. Check with known-good discs like the Install DVD
that came with the computer.
3. Verify if noise occurs without media in optical
drive. If so, verify if noise made by hard drive or
fans.
4. Refer to kBase #TS3204: iMac (Late 2009)
Evaluating normal noises.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 73
Deep Dive
Check Result Action Code
1. Test optical drive with dierent
source of media. Does the noise
issue remain?
2. Reseat optical drive in
enclosure. Does noise issue
remain?
3. Install known-good optical
drive in enclosure. Does noise
issue remain?
4. Compare system with similar
model for optical drive noise in
operation and verify that noise
level is similar.
Yes Go to step 2.
No Issue due to unbalanced
media. Recommend using
dierent media.
Yes Go to step 3.
No Issue resolved by reseating
drive in enclosure.
Yes Go to step 4.
No Replace optical drive. J04
Yes Noise level of optical
drive appears to be within
specication. Return system
to user.
No Check for other causes of
noise in the system.
SD Card Will Not Insert Into Slot
Unlikely cause: LCD panel, logic board, optical drive, hard drive
Quick Check
Symptom Quick Check
SD Card will not insert into slot
• SD memory card does not fully
seat into slot
• Card slot does not align with
enclosure.
Deep Dive
Check Result Action Code
1. Verify if known-good SD card
ts in slot.
1. The SD card must be a 32 mm by 24 mm by 2.1
mm. You can also use thinner cards, such as Multi
Media Cards (MMC).
2. Clear any obstruction in SD card slot.
Yes Ask user to replace defective
or out-of-spec SD card.
No Loosen the SD board screws,
then insert known-good SD
card again. Go to step 2.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 74
2. Verify if known-good SD card
now ts in slot.
Yes Tighten SD reader board
screws. Go to step 3.
No Replace SD card reader, retest. X24
3. Verify if SD card now ejects
and inserts without issue.
Yes Issue resolved by SD card
reader alignment.
No Replace SD card reader. X24
SD Card Not Recognized
Unlikely cause: LCD panel, logic board, optical drive, hard drive
Quick Check
Symptom Quick Check
SD Card Not Recognized
• Card does not show up on
desktop or in System Proler
1. Insert user’s SD card into a known-good system
and verify that it functions properly. If card
cannot be read, contact card manufacturer for
support options.
2. Verify SD card slot with known-good SD card.
3. Check correct drivers are installed for user’s SD
card type. Standard SD cards are supported by
Mac OS X, but others may require specic driver
software to be used.
2010-09-03
Deep Dive
Check Result Action Code
1. Verify if SD card inserts
correctly in SD slot.
2. Unlock and insert user’s SD
card and verify it shows up on
desktop or in System Proler.
3. Insert a known-good unlocked
SD card and verify if read/write
capabilities are working.
Yes Go to step 2.
No Go to SD Card Will Not Insert
Into Slot.
Yes Go to step 6.
No Go to step 3.
Yes User’s SD card not functioning
properly. Contact card
manufacturer for support.
No Go to step 4.
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 75
4. Run System Proler and verify
if SD card reader is now listed
in USB devices.
Yes Go to step 5.
No Reseat SD cable at SD card
reader and logic board
If issue persists, replace
SD cable.
If issue persists after cable
was replaced, replace
SD card reader.
If issue persists after card
reader was replaced, replace
logic board.
X03
X24
M17
5. Verify if a known-good
unlocked SD card can now be
correctly read and written.
6. Lock the user’s SD card and
verify if it can’t be written.
Yes Go to step 6.
No Replace SD card reader. X24
Yes Issue resolved.
No Replace SD card reader. M17
Uncategorized Symptoms
Check Result Action Code
1. Verify if existing symptom code
applies to issue reported by
user.
Yes Jump to appropriate
symptom code ow.
No
Document reported failure
and send feedback to
smfeedback6@apple.com
stating that a suitable
symptom code wasn’t found.
Provide as much detail as
possible.
N99
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Mass Storage 76
Communications
AirPort/Bluetooth Issues
Quick Check
Symptoms Quick Check
AirPort/Bluetooth Issues
• Unable to join networks or pair
devices
• AirPort card or functionality not
available
• Bluetooth card or functionality
not available
• Intermittent device or
connection dropouts
• Limited wireless range
1. Verify that AirPort or Bluetooth is turned ON, and
for AirPort issues make sure that a network is
selected.
2. (AirPort) Run the Apple System Proler and verify
that installed AirPort card supports the channel
number used by the wireless access point.
3. (AirPort) Check if the wireless access point
requires special connection and encryption
protocols.
4. (AirPort) Check for nearby sources of interference
such as microwave ovens or cordless phones. See
kBase #HT1365: AirPort: Potential source of
interference.
5. (AirPort) Check the number of users trying to
use AirPort in the area for possible network
congestion (available bandwidth).
6. (Bluetooth) If user complaints about a Bluetooth
issue with an input device, rst use a knowngood Bluetooth input device to perform tests
with computer. Then test user’s Bluetooth device
on known-good computer to dene which side
is creating the communication issue. See kBase
#TS3048: Troubleshooting wireless mouse and
keyboard issues.
2010-09-03
7. Isolate potential OS issues by starting up
from original Install media for the computer, a
same-model computer in Target Disk Mode, or
compatible known-good OS on an external drive.
Both AirPort and Bluetooth services are available
when booted from Install disc.
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 77
Deep Dive
Check Result Action Code
1. Open System Proler. AirPort
is listed under Network, while
Bluetooth is listed under USB.
Verify if both AirPort and
Bluetooth cards are recognized.
2. (Airport) Wait at least 15
seconds after computer has
been shutdown and reseat
AirPort card connection on
logic board. Verify if AirPort
card is now listed in Apple
System Proler.
3. (Airport) After card has been
replaced, verify if AirPort card
is now listed in Apple System
Proler.
4. (Airport) Enable AirPort and
verify if known local AirPort
networks are available,
or create a computer-tocomputer network with
another Macintosh computer
using AirPort. See http://
docs.info.apple.com/article.
html?path=AirPort/5.0/en/
ap2110.html. Verify if you
connect successfully.
Yes Install all available software
updates for AirPort/Bluetooth
and re-test. If issue persists
after software update, go to
step 4 for AirPort, or go to
step 6 for Bluetooth.
No Go to step 2 for AirPort.
Go to step 6 for Bluetooth.
Yes Issue resolved by reseating
AirPort card.
No Wait at least 15 seconds after
computer has been shutdown
and replace AirPort card and
re-test. Go to step 3.
Yes Issue resolved by replacing
AirPort card.
No Replace logic board and re-
test.
Yes Issue resolved.
No Go to step 5.
N01
M11
2010-09-03
5. (Airport) Check and reseat the
two antennas to the AirPort
card. Verify if you can connect
to known AirPort network.
Yes Issue resolved.
No Replace AirPort card. If issue
persists, replace AirPort
antenna(s). If the damaged
antenna is embedded in rear
housing behind Apple logo,
replace rear housing.
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 78
N04
X03
6. (Bluetooth) Verify that
computer and known-good
Bluetooth device are both in
discoverable mode. Verify if
you can now successfully and
reliably pair the device.
Yes Issue resolved.
No If Bluetooth cannot be
enabled, replace Bluetooth/
camera cable. If issue persists
replace Bluetooth card and
retest. Go to step 8.
If Bluetooth can be enabled
but Bluetooth communication
persists, replace Bluetooth
antenna. Go to step 7.
X03
N15
X03
7. (Bluetooth) Re-test with new
Bluetooth antenna and verify if
Bluetooth issues are resolved.
8. (Bluetooth) Re-test with new
Bluetooth cable/card and verify
if Bluetooth issues are resolved.
Yes Issue resolved.
No Replace Bluetooth card. N15
Yes Issue resolved.
No Replace logic board. M11
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 79
AirPort Card Kernel Panic
Quick Check
Symptoms Quick Check
AirPort Card Kernel Panic
• Kernel Panic on startup
• Kernel Panic or freezing while
attempting to connect to WiFi
networks
• Kernel Panic while transferring
data on WiFi networks
1. Isolate OS by starting up from original Install
media for this computer, a same-model computer
in Target Disk Mode, or compatible known-good
OS on an external drive. AirPort and Bluetooth
services are available when booted from the
Install disk.
2. Ensure that all software and rmware updates for
the computer and AirPort have been installed.
Deep Dive
Check Result Action Code
1. Wait at least 15 seconds after
computer has been shutdown
before disconnecting AirPort
card from logic board. Verify if
computer now starts without
kernel panic.
Yes Reseat AirPort card and retest.
If problem continues replace
AirPort card. Go to step 2.
No Kernel panic not related
to AirPort. Restart from
Install DVD or known-good
bootable external drive and
check Panic.Log le on user’s
hard drive to nd out which
is the crashing I/O interface.
Also troubleshoot installed
Mac OS X software.
2010-09-03
2. With replacement AirPort card
installed, verify if computer
starts now without kernel
panic.
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 80
Yes AirPort card issue. Issue
resolved.
No Replace logic board. M11
N13
Ethernet Port/Device Issue
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
Ethernet Port/Device Issue
• No Ethernet device present
• Unable to access network
resources
• Ethernet device shows no
connection
• Ethernet device unable to an IP
address
• Slow network performance
1. Check Ethernet cable for damage. Try a
known good Ethernet cable – CAT5 or better
recommended for 100Mbps+ connections.
2. Check Ethernet ports on the computer and wall/
switch for dust, debris, damage or bent pins.
3. Ensure distance from networking infrastructure is
less than 300 feet/ 105 meters.
4. Verify port, cable and network hardware with a
known good system. Isolate rewall, MAC address
ltering or hardware access control devices.
5. Isolate OS by starting up from original Install
media for this computer, a same-model computer
in Target Disk Mode, or compatible known-good
OS on an external drive.
Deep Dive
Check Result Action Code
1. Visually inspect Ethernet port
of computer and ensure that all
pins will make physical contact
with the Ethernet cable.
Yes Go to step 2.
No Pins are damaged, bent at or
missing. Replace logic board.
M24
2010-09-03
2. Boot from original Install media.
Verify Network Link status is
active by using Network Utility
under the “Info” tab. Verify if the
Link Status is “Active”.
3. Connect computer to another
Mac using CAT5 Ethernet
cable. See article http://
docs.info.apple.com/article.
html?path=Mac/10.6/en/8429.
html. Verify if you connect
successfully.
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 81
Yes Go to step 3.
No If same Ethernet cable gives
an “Active” link status on a
known-good, same-model
computer, replace logic board.
Yes Ethernet communication
good. Go to step 4.
No If same Ethernet cable and
computer connects to a
known-good, same-model
computer, replace logic board.
M10
M10
4. Check for speed and duplex
issues on network. Open
System Preference > Network;
click the Advanced button,
then the Ethernet tab. Verify if
the speed and duplex reported
are what is expected.
Yes Go to step 5.
No
Change speed and duplex
settings. See article http://
docs.info.apple.com/article.
html?path=Mac/10.6/
en/8711.html. Go to step 6.
5. Check for MTU (Maximum
Transmission Unit) issues. See
kBase #HT2532: Mac OS X:
How to change the MTU for
troubleshooting purposes.
Verify if changing MTU settings
on computer resolves issue.
6. If changing speed, duplex
or MTU settings allows
connectivity, check with a
known-good, same-model
computer. Verify if known-good
computer produces the same
results.
Yes Go to step 6.
No Ethernet controller damaged.
Yes Check with ISP or Network
No Verify with known good OS.
Wireless Input Device Doesn’t Pair
Quick Check
Symptoms Quick Check
M10
Replace logic board.
Administrator concerning
speed, duplex & MTU settings.
M10
If issue persists, replace logic
board.
2010-09-03
Wireless Input Device Doesn’t
Pair
• Can’t get system to recognize a
Bluetooth keyboard, mouse or
trackpad
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 82
7. Check computer with a known-good Bluetooth
input device to test computer side.
8. Test Bluetooth device side with a known-good
Mac OS X 10.6.x up to date computer with
installed Bluetooth device driver.
9. Ensure that device is being used within 30-foot
range for Bluetooth devices.
10. See kBase #TS3048: Troubleshooting wireless
mouse and keyboard issues.
Deep Dive
Check Result Action Code
1. Without any wired input
devices connected, and
with a known-good Apple
wireless mouse /trackapd in
discoverable mode, startup the
computer. Verify if computer
shows the Bluetooth Mouse
Setup Assistant.
2. Connect a wired mouse and
run Apple System Proler. Verify
if Bluetooth interface is listed
under USB in System Proler.
3. Using an externally connected
display, run Apple System
Proler and verify if Bluetooth
interface is listed under USB in
System Proler.
4. Run Apple System Proler.
Verify if Bluetooth interface
is listed under USB in System
Proler.
Yes Bluetooth hardware is active.
Go to step 6.
No Go to step 2.
Yes Bluetooth hardware is
present. Go to step 6.
No Remove glass and LCD panel,
reseat both ends of cable
between Bluetooth board and
logic board. Go to step 3.
Yes Bluetooth hardware is now
present. Go to step 6.
No Replace Bluetooth cable.
Go to step 4.
Yes Bluetooth hardware is now
present. Go to step 6.
No Replace Bluetooth board.
Go to step 5.
X03
N15
5. Run Apple System Proler.
Verify if Bluetooth interface
is listed under USB in System
Proler.
6. Run Software Update and
apply any available Bluetooth
updates. Activate Bluetooth
in System Preferences (or
Apple menu icon) then select
“Congure a new Bluetooth
device” (or run Bluetooth
Mouse Setup Assistant). Verify
if a known-good Bluetooth
mouse/trackpad is seen.
7. With a known-good Apple
Wireless mouse/trackpad on
and in discoverable mode,
verify if you can successfully
pair the device with the
assistant.
Yes Bluetooth hardware is now
present. Go to step 6.
No Replace logic board. M11
Yes Bluetooth discovery is now
active. Go to step 7.
No Replace Bluetooth antenna. X03
Yes Check for stability.
Go to step 8.
No
Go to Wireless Input Device
Loses Connection.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 83
8. With known-good Apple
Wireless mouse/trackpad
paired, verify if the device stays
connected.
Yes Issue resolved.
No Inspect and reseat Bluetooth
antenna cable. Replace a
damaged antenna cable, or
Bluetooth board if its antenna
connector is damaged.
Go to step 9.
X03
9. With user’s mouse/trackpad
paired, verify if the mouse stays
connected.
Yes Antenna issue. Issue resolved.
No Go to Wireless Input Device
Uncategorized Symptoms
Quick Check
Symptoms Quick Check
Uncategorized Symptoms
• Unable to locate appropriate
symptom code.
1. Verify System Preferences/Network settings
are congured appropriately to support
communication method.
2. For Ethernet connection issues verify that cable
being used functions when used with another
known-good system.
3. For wireless connection issues review user
environment to determine whether possible
interference from other 2.4GHz communications
devices might be contributing to issue. See
kBase #HT1365: AirPort: Potential sources of
interference
Resassemble system.
Loses Connection.
2010-09-03
Deep Dive
Check Result Action Code
1. Verify if existing symptom code
applies to issue reported by
user.
iMac (21.5-inch, Mid 2010) Symptom Charts — Communications 84
Yes Jump to appropriate
symptom code ow.
No
Document reported failure
and send feedback to
smfeedback6@apple.com
stating that a suitable
symptom code wasn’t found.
Provide as much detail as
possible.
N99
Input/Output Devices
Apple Remote Inoperable
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
Apple Remote Inoperable
• Apple Remote doesn’t bring up
Front Row
• Apple Remote doesn’t control
iTunes
• Apple Remote doesn’t control
computer volume
1. Make sure Apple Remote is within 30 ft. of
computer, and has an unobstructed line-of-sight
to computer.
2. Make sure lens end of Apple Remote is pointing
directly at front of computer.
3. Make sure “Disable remote control infrared
receiver” checkbox in System Preferences >
Security is not checked.
4. Ensure that all software and rmware updates for
this model have been installed to take advantage
of any available bug xes.
Deep Dive
Check Result Action Code
1. Open Photo Booth or iChat’s
video preview window. Point
Apple Remote at built-in
camera and press any button
on Apple Remote. Verify if a
white, ashing light is visible in
video preview.
Yes Apple Remote is functioning.
Go to step 2.
No Replace Apple Remote
battery.
Go to step 3.
2010-09-03
2. Open System Preferences
> Security. Verify if “Unpair”
setting is available in this
preference panel.
3. With replacement battery,
verify if white ashing light
is visible coming from Apple
Remote in video preview
window.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 85
Yes Click “Unpair” button to
disable possible pairing with
another Apple Remote.
Go to step 4.
No Possible IR board issue.
Go to step 5.
Yes Battery issue. Issue resolved. X05
No Apple Remote defective.
Replace Apple Remote.
X04
4. After clicking “Unpair”, verify if
the computer now responds to
the Apple Remote.
Yes Pairing issue. Issue resolved.
No Possible IR board issue.
Go to step 5.
5. Open Apple System Proler.
Verify if “IR Receiver” is listed in
USB list of devices.
6. Check that IR board is correctly
tted and aligned with Apple
window and that lens is not
blocked by any foreign material
and re-test. Verify if computer
responds to Apple Remote.
7. After reseating or replacing
IR board, verify if “IR Receiver”
is listed under USB in Apple
System Proler, and that
computer now responds to
Apple Remote.
8. After replacing IR cable, verify if
“IR Receiver” is listed under USB
in Apple System Proler, and
that computer now responds to
Apple Remote.
Yes IR board reporting on USB
bus. Check for lens block.
Go to step 6.
No Inspect and reseat IR cable
connection to logic board.
Go to step 7.
Yes Lens blocked or sensor not
aligned with window. Issue
resolved.
No Lens damaged or inoperable.
Replace IR board. Go to step 7.
Yes IR module reseated/replaced.
Issue resolved.
No If IR board was only reseated,
replace IR cable. Go to step 8.
Yes IR cable replaced. Issue
resolved.
No Replace IR board. Go to step 9.
X03
X03
X03
2010-09-03
9. After replacing IR board, verify
if “IR Receiver” is listed under
USB in Apple System Proler,
and that computer now
responds to Apple Remote.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 86
Yes IR board replaced. Issue
X03
resolved.
No Replace logic board. M23
Audio: Microphone
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
Audio: Microphone
• Microphone not working
• Microphone audio garbled
• No sound
1. Verify that no tape, sticky notes, or other objects
are blocking microphone located on top of
computer near camera. Microscopic perforations
on top of computer must be free of obstructions
in order for microphone to function.
2. Go to System Preferences > Sound > Input.
Verify that sound input device is set to internal
microphone.
3. Go to System Preferences > Sound > Input.
Verify that “Input volume” setting is set above
minimum level.
4. Go to System Preferences > Sound > Input.
Verify that “Input level” indicator moves when
speaking into microphone.
Deep Dive
Check Result Action Code
1. Verify if boot chime is present
when system is powered
ON. Make sure audio output
preferences are not set to mute.
Yes Go to step 2.
No Reset PRAM and retest.
2010-09-03
2. Make sure no cables are
connected to external sound
input/output ports. Go to
System Preferences > Sound >
Input and verify that “Internal
microphone” is an available
option.
3. Go to System Preferences >
Sound > Input and verify if
“Input volume” is set above
minimum sensitivity.
4. Go to System Preferences
> Sound > Input and verify
if “Input level” indicator
moves when speaking into
microphone.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 87
Yes Go to step 3.
No Replace audio cable. M09
Yes Go to step 4.
No Set “Input volume” slider to
middle position. Retest.
Yes Microphone and audio input
functioning. Go to step 6.
No Suspect bad microphone
connection. Reseat
microphone connector on
logic board. Go to step 5.
5. Inspect microphone cable
routing and verify if cable is
pinched or damaged.
Yes Replace rear housing
(microphone cable not
available separately).
No Go to step 6.
L14
6. Record sound sample using
GarageBand or iMovie. Verify if
sound quality of sound sample
is normal during playback.
Yes Microphone circuitry OK.
Return system to user.
No Replace logic board. M09
Audio: Built-in Speakers Have Distorted Sound
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
Audio: Built-in Speakers Have
Distorted Sound
• No audio from one or both
speakers.
• Audio from speakers distorted
1. Go to System Preferences > Sound > Output.
Verify that sound output device is set to internal
speakers and that balance control is set to the
center position.
2. Obtain known-good high-quality sound le or
use iTunes Store sound samples to evaluate
sound quality. Verify suspect sound les on
another system to determine if distortion is
caused by computer or sound le.
2010-09-03
3. Set volume control to mid-range. Overdriving
built-in speakers can cause distortion.
Deep Dive
Check Result Action Code
1. Go to System Preferences >
Sound > Output. Set speaker
balance 100% to LEFT speaker
and play a known-good sound
le. Verify if sound is generated
by LEFT speaker and that sound
quality is acceptable.
2. Set speaker balance 100%
to RIGHT speaker and play a
known-good sound le. Verify
if sound is generated by RIGHT
speaker and that sound quality
is acceptable.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 88
Yes LEFT speaker and amplier
circuitry OK. Go to step 2.
No Distortion detected in LEFT
speaker. Set Balance slider to
middle position. Go to step 3.
Yes RIGHT speaker and amplier
circuitry OK. Set Balance slider
to middle. Go to step 3.
No Distortion detected in RIGHT
speaker. Go to step 4.
3. Connect external speakers or
headphones to audio-out port
and play a known-good sound
le. Verify if sound quality is
acceptable.
Yes Suspect bad speaker.
Go to step 4.
No Audio CODEC or amplier
issue suspected. Replace logic
board and retest.
M09
4. Inspect LEFT and RIGHT
speaker cones and speaker
connection cable for damage.
Verify if speakers have visible
damage.
5. Install known-good speaker
into location where distorted
sound was heard. Verify if
sound quality improves.
Yes Replace damaged speaker.
Retest.
No Go to step 5.
Yes Replace speaker. L11
No Speaker amplier issue
suspected. Replace logic
board.
Audio: Built-in Speakers Have No Sound
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
Audio: Built-in Speakers Have No
Sound
• No audio from one or both
speakers.
• Audio from speakers distorted
1. Go to System Preferences > Sound > Output.
Verify that sound output device is set to internal
speakers.
2. Go to System Preferences > Sound > Output.
Verify that “Output volume” setting is set above
the minimum level and that “Mute” checkbox is
not selected.
L11
M09
2010-09-03
3. Go to System Preferences > Sound > Output.
Verify that “Balance” slider is set to middle
position so left and right speakers are both used.
Deep Dive
Check Result Action Code
1. Verify if boot chime is present
when system is powered
ON. Make sure audio output
preferences are not set to mute
and volume is set to mid-range.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 89
Yes Go to step 2.
No Reset PRAM and retest.
2. Make sure no cables are
connected to external sound
input/output ports. Go to
System Preferences > Sound >
Output and verify that “Internal
speakers” is an available option.
Yes Go to step 3.
No If “Headphones” is the only
available sound output
device, replace audio cable.
If “Digital output” is the
only available sound output
device, reseat audio cable to
logic board. If issue persists,
replace audio cable.
If issue persists, replace logic
board.
L11
L11
M09
3. Go to System Preferences >
Sound > Output. Set speaker
balance 100% to LEFT speaker
and play a known-good sound
le. Verify if sound is generated
by LEFT speaker and that sound
quality is acceptable.
4. Set speaker balance 100%
to RIGHT speaker and play a
known-good sound le. Verify
if sound is generated by RIGHT
speaker and that sound quality
is acceptable.
5. Verify if user-reported audio
issue has been resolved.
6. Boot system from Install
DVD or another known-good
bootable volume. Verify if issue
still occurs.
Yes LEFT speaker and amplier
circuitry OK. Go to step 4.
No No audio in LEFT speaker.
Go to step 7.
Yes RIGHT speaker and amplier
circuitry OK. Set Balance slider
to middle. Go to step 5.
No No audio in RIGHT speaker.
Go to step 7.
Yes Issue no longer present.
Return system to user.
No Go to step 6.
Yes Go to step 7.
No Known-good boot volume
works OK. Troubleshoot for
software issue. Isolate if issue
is application-specic or a
possible OS conict.
2010-09-03
7. Connect external speakers or
headphones to audio-out port
and play a known-good sound
le. Verify if sound quality is
acceptable.
8. Disconnect and carefully
inspect audio connectors
assembly and its connection to
logic board for damage such as
bent pins or pinched/cut wires.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 90
Yes Logic board, internal
speakers, and audio-out port
functioning correctly. Return
system to user.
No Go to step 8.
Yes Replace damaged audio
L14
connectors asembly. If issue
persists, verify if symptom has
changed.
No Replace logic board. M09
Camera Issues
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans, speakers, microphone
Quick Check
Symptoms Quick Check
Camera Issues
• Camera not detected
• No green LED for camera
• Excessive blooming
• Poor White Balance
• Poor Focus
• Green image
• Image distortion
1. Launch Apple System Proler and conrm that
system’s USB hub and built-in camera are visible.
2. Verify camera lens and glass panel are clean and
free of contaminants. Clean glass panel if needed.
3. Launch Photo Booth to verify that green indicator
LED near camera lens turns on and image quality
is acceptable.
Deep Dive
Check Result Action Code
1. Launch Apple System Proler
and verify built-in camera is
visible in USB list of devices.
2. Launch Photo Booth. Verify if
green LED near camera lens
turns ON and image appears
normal.
Yes Camera recognized.
Go to step 2
No Inspect and reseat camera
cable connection on logic
board. Go to step 2.
Yes Camera functioning. Return
system to user.
No Remove glass and clean both
sides. Clean camera lens.
If issue persists, replace
camera cable.
If issue persists, replace
camera.
If issue persists, replace logic
board.
X07
X07
M13
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 91
FireWire Device Not Recognized
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
FireWire Device Not Recognized
• FireWire hard drive not
recognized
• FireWire optical drive not
recognized
• FireWire camera not recognized
• FireWire printer not recognized
1. For external FireWire drives, make sure any
external power source is plugged in and
operating to isolate a power issue with the
device.
2. Test a known-good FireWire device to isolate a
failed peripheral issue.
3. Test a known-good FireWire cable to isolate a
FireWire cable issue.
4. Ensure that all software and rmware updates for
this model have been installed to take advantage
of any available bug xes.
5. Launch Apple System Proler and verify if the
aected FireWire device is visible on FireWire
bus. If yes, then FireWire port and cable are
functioning properly. Contact FireWire device
manufacturer to verify that device is supported.
Deep Dive
Check Result Action Code
1. Unplug all FireWire devices
from computer. Reset PRAM.
Reconnect FireWire device
in question. Verify if FireWire
device is recognized.
Yes Issue resolved.
No Possible logic board failure.
Go to step 2.
2010-09-03
2. Use a known-good FireWire
cable with a known-good
FireWire device (such as
another Mac in Target Disk
Mode). Verify if FireWire device
is recognized.
3. Verify if FireWire device is
recognized on a known-good
same model computer.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 92
Yes Try FireWire device in question
with a known-good computer
of same model. Go to step 3.
No FireWire not recognized.
Replace logic board.
Yes Go to step 4.
No Device may need additional
power. Use a powered FireWire
hub. Go to step 5.
M12
4. Verify if FireWire device is
recognized with a knowngood FireWire cable on user’s
computer.
Yes FireWire cable issue. Issue
resolved.
No FireWire device may need
additional power. Go to step 5.
5. Using a powered FireWire
hub, and having installed any
software or rmware updates
for the device, verify if FireWire
device is now recognized.
6. Create a new user in System
Preferences > Accounts and
log out current user. Log in
on new user account and
verify if FireWire device is now
recognized.
Yes Device recognized. Required
additional power from hub or
update. Issue resolved.
No Device may require additional
software, or there may be a
conict in the Mac OS. Go to
step 6.
Yes Software Issue. Troubleshoot
software on User account. Issue
resolved.
No Apply all Mac OS and FireWire
specic updates. If issue
persists, contact device
manufacturer for support.
FireWire port and cable have
been veried.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 93
USB Device Not Recognized
Unlikely cause: LCD display, power supply, hard drive, optical drive, fans
Quick Check
Symptoms Quick Check
USB Device Not Recognized
• USB wired keyboard/mouse not
recognized
• USB external drive not
recognized
• USB camera not recognized
• USB printer not recognized
Deep Dive
1. Reset SMC.
2. For printers and external USB drives, make sure
any external power source is plugged in and
operating to isolate a power issue with device.
3. The iMac has 4 USB ports on rear of computer. Try
each port to isolate a particular port malfunction.
4. Test with a known-good wired keyboard or
mouse to isolate a failed peripheral issue.
5. Test with a known-good USB cable when dealing
with a printer or external USB drive, to isolate a
USB cable issue.
6. Ensure that all software and rmware updates for
this model have been installed to take advantage
of any available bug xes.
7. Launch Apple System Proler and verify if device
is visible on USB bus. If yes, then the USB port and
cable are functioning properly. Contact device
manufacturer to verify that device is supported.
2010-09-03
Check Result Action Code
1. Unplug all USB devices from
the computer except for USB
keyboard and mouse. Start
computer and reset PRAM.
Verify if USB keyboard and
mouse are recognized.
2. Verify if Bluetooth Mouse Setup
assistant launches after startup.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 94
Yes Test with all USB ports to
ensure all USB ports working
as expected. Replace logic
board for any port failures.
No Reset SMC. Go to step 2.
Yes Bluetooth detected, but
external USB devices not
recognized. Go to step 3.
No Disconnect USB keyboard and
mouse. Go to step 4.
3. Verify if a known-good USB
keyboard and mouse are
recognized.
Yes Test original USB mouse and
keyboard. Replace if still not
recognized. Go to step 5.
4. With no USB devices
connected, restart computer.
Verify if Bluetooth Mouse Setup
assistant launches after startup.
5. With known-good USB
keyboard and mouse working,
test USB peripheral in question
(USB hard drive or printer, etc.)
Verify if device is recognized
in Apple System Proler under
USB.
6. Verify if using a powered USB
hub resolves the issue.
No External USB ports not
functioning. Replace logic
board.
Yes Bluetooth detected.
Go to step 3.
No Bluetooth not recognized.
Internal and external USB not
functioning. Replace logic
board.
Yes Device recognized. Test in all
USB ports to ensure all USB
ports working as expected.
Replace logic board for any
port failures.
No Device may require more
power than supplied by USB
ports. Test with a powered
USB hub. Go to step 6.
Yes Test device on the same
USB port of a same-model
computer without any other
USB port populated. If other
computer does not require
a powered USB hub to allow
the device functionality,
replace logic board.
M15
M15
M15
M15
2010-09-03
No The computer’s USB ports
and cable have been veried.
Ensure all software and
rmware updates have
been applied for computer
and device. If issue persists,
contact device manufacturer
for support.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 95
Wired Keyboard Does Not Function Properly
Quick Check
Symptoms Quick Check
Wired Keyboard Does Not
Function Properly
• Some or all keys on the
keyboard don’t work
• Eject key or Caps Lock key
doesn’t seem to work
• Some keys don’t work as
expected
1. Reset SMC
2. Open System Preferences > Universal Access >
Mouse & Trackpad and verify that Mouse Keys
is turned OFF. When enabled, Mouse Keys can
disable functionality of some or most keys,
depending on keyboard used.
3. The iMac has 4 USB ports on rear of computer.
Make sure to try each port to isolate a particular
port malfunction.
4. Test with a known-good wired keyboard to
isolate a failed peripheral issue.
5. Test wired keyboard on a known-good, samemodel computer. If it works on the other
computer, this may indicate a bad USB port if
keyboard doesn’t work at all on user’s computer,
or a software issue if keyboard is working but not
as expected on user’s computer.
6. Ensure that all software and rmware updates for
this model have been installed to take advantage
of any available bug xes.
Deep Dive
Check Result Action Code
1. Verify if all keys on keyboard
work.
2. Verify if Caps Lock is working as
expected.
3. Verify if media Eject key is
working as expected. Note that
to prevent accidentally ejecting
media, Mac OS X adds a slight
delay to the media Eject key
before it takes eect.
Yes Go to step 2.
No Go to Keyboard: Specic
Keys Do Not Respond.
Yes Go to step 3.
No Go to Keyboard: Specic
Keys Do Not Respond
Yes Go to step 4.
No Go to step 5.
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 96
4. Open System Preferences >
Speech. Verify if the “Speak
selected text when the key is
pressed” checkbox is selected.
Yes The key combination to speak
text cannot be used for any
other purpose. Either disable,
or change to a more rare
key combination (including
Shift, Command, Option and
Control).
No Go to step 6. M15
5. With optical media in the drive,
hold the media Eject key. Verify
if the eject symbol appears on
screen and that optical media
is ejected if present.
6. Open System Preferences >
Language and Text > Input
Menu. Check “Keyboard Viewer”.
From the Input Menu (ag) in
the Menu Bar, choose “Show
Keyboard Viewer”. Verify if keys
pressed appear in Keyboard
Viewer.
7. Open TextEdit or another text
application and try typing
something using the nonresponding keys. Verify if
they are typed in this other
application.
Yes Normal media eject key delay.
No repair necessary.
No Go to Optical Drive Won’t
Accept/Eject Media.
Yes Keys recognized.
Go to step 9.
No Keys not recognized.
Replace keyboard.
Yes Application-specic issue.
Troubleshoot application.
No Create a new user account
in System Preferences >
Accounts, log out from
current user and log in with
new user to isolate a User
account related issue. If issue
persists, reinstall Mac OS X
from Install DVD.
K01
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 97
Keyboard: Specic Keys Do Not Respond
Quick Check
Symptoms Quick Check
Keyboard: Specic Keys Do Not
Respond
• One or more keys do not
respond when pressed
• Key sticks
• Keycap missing
1. If wireless keyboard is being used verify that it is
properly paired with computer. Go to Wireless
Input Device Doesn’t Pair symptom ow to
resolve pairing issues.
2. The caps lock key has a built-in delay to reduce
accidental activation and must be held for
approximately ½ second for it to be activated. See
kBase #TS1578: Keyboard Caps Lock modied
to reduce accidental activation.
3. Inspect keyboard for signs of liquid spills or other
contamination. Apple’s warranty does not cover
accidental damage.
4. If keycap is loose attempt to reattach it.
5. Use the Keyboard Viewer menu to check every
key.
6. Recheck keyboard with a known-good computer.
with an up to date Mac OS X 10.6.x
7. Replace keyboard if issue is conrmed (K01 for
inoperative keys, K17 for wrong/falling keycaps).
2010-09-03
Wired Keyboard/Mouse Not Recognized
Quick Check
Symptoms Quick Check
Wired Keyboard/Mouse Not
Recognized
• USB wired keyboard/mouse not
recognized when plugged in.
• Mouse scroll ball not working
or not working as expected.
• Mouse buttons not working or
not working as expected.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 98
1. Reset SMC.
2. The iMac has 4 USB ports on rear of computer.
Make sure to try each port to isolate a particular
port malfunction.
3. Test with a known-good wired keyboard or
mouse to isolate a failed peripheral issue.
4. Test a mouse when connected directly to ports
on the back of iMac to isolate a keyboard USB
port issue.
5. Ensure that all software and rmware updates for
this model have been installed.
Deep Dive
Check Result Action Code
1. Verify if computer recognizes
keyboard or mouse when
plugged into rear USB ports on
back of iMac.
2. Verify if keyboard is working as
expected.
3. Verify if Mighty Mouse has an
issue with scroll ball.
4. Verify if mouse has an issue
with buttons.
Yes Test device in all USB ports to
ensure all other USB ports are
working as expected.
Replace logic board if any
USB port on rear fails.
Replace keyboard if any USB
port on keyboard fails.
Go to step 2.
No
Yes Go to step 3.
No Go to Wired Keyboard Does
Yes See kBase #HT1537: How to
No Go to step 4.
Yes Go to step 7.
No Go to step 5.
Go to USB Device Not
Recognized.
Not Function Properly.
clean Mac products.
M15
K11
5. Verify if mouse has an issue
with tracking.
6. Try using mouse on another
surface. Non-reective, opaque
surfaces without repetitive
patterns work best. The surface
should be clean but not shiny.
Verify if mouse tracks correctly
when used on another surface.
7. See kBase #HT1581:
Troubleshooting Mighty
Mouse and determining
expected behavior. Verify if
this article resolves issue.
Yes Go to step 6.
No Go to step 7.
Yes Surface issue. Issue resolved.
No Go to step 7
Yes Issue resolved.
No Replace wired Mighty Mouse. K99
2010-09-03
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 99
Wireless Input Device Does Not Pair
Quick Check
Symptoms Quick Check
Wireless Input Device Does Not
Pair with computer
• Apple Wireless Keyboard/Magic
Mouse/Magic Trackpad not
recognized when powered on.
• Unable to pair Bluetooth input
device with computer.
• Apple Magic Mouse buttons
not working.
• Apple Magic Trackpad clicking/
tracking/tapping actions not
working.
1. Remove/ reinstall batteries into device to check
they were not reversely inserted.
2. Ensure that all software and rmware updates
have been installed to take advantage of any
available bug xes.
3. Ensure that the Bluetooth device software has
been installed on test computer.
4. Install known-good charged batteries in
Bluetooth device. Press power button to check
that green LED stays lit for at least 3 seconds.
5. Review kBase #TS3048: Troubleshooting
wireless mouse and keyboard issues.
6. Use a known-good up-to-date Mac OS X
computer with Bluetooth enabled in Bluetooth
Preferences, where a known-good similar
Bluetooth device could be previously paired, and
where a wired mouse is connected.
7. Try to pair the aected Bluetooth device using
the Bluetooth Setup Assistant Utility.
8. (Apple Wireless Keyboard , Magic Mouse or Magic
Trackpad) Download and run the Bluetooth
Service Diagnostic utility (available in the Disk
Images page of GSX/Service Source).
2010-09-03
9. (Apple Wireless Keyboard , Magic Mouse or Magic
Trackpad) After Bluetooth Service Diagnostic
utility passed, pair the device again, using the
Bluetooth Setup Assistant.
iMac (21.5-inch, Mid 2010) Symptom Charts — Input/Output Devices 100
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