Apple | iMac (Early 2006 20-inch) | Specifications | Apple iMac (Early 2006 20-inch) Specifications

 Service Source
iMac (Early 2006 20-inch)
© 2006 Apple Computer, Inc. All rights reserved.
iMac (Early 2006 20-inch)
Contents
What’s New 4
iMac (Early 2006) 4
Take Apart
General Information 6
Product View 6
Identifying the iMac (Early 2006 20-inch) Computer 6
What’s New 7
Tools Required 9
Orientation 10
Serial Number Location 10
Safety 11
Opening the Computer 12
EMI Shielding 12
Access Door 13
Memory 15
Front Bezel 18
Camera Board 26
Lower EMI Shield 32
IR Board 35
LCD Display Panel 40
Speakers 48
AirPort Extreme Card 54
Bluetooth Card 57
Optical Drive 60
Hard Drive 67
Power Supply, AC/DC 74
ii
Logic Board 80
AC Line Filter 91
Fan, Hard Drive 95
Fan, Optical Drive 99
Fan, CPU 102
Power Supply, DC/DC, Inverter 105
Ambient Light Sensor Board 108
Cable, Camera and IR 111
Bluetooth Antenna 114
AirPort Antenna 118
Clutch Mechanism 122
Chassis 126
Rear Housing 129
Stand 132
Troubleshooting
General Information 137
Serial Number Location 137
Power On Self Test (POST) 137
DDR Memory 138
Symptom Charts 139
How to Use the Symptom Charts 139
Power Issues 140
No Video 142
Display 144
Hard Drive 145
Optical Drive 147
Fan Sound 152
AirPort/ 155
IR Remote 156
IR Sensor/Receiver 157
Built-in iSight Camera 158
Speakers 160
Mouse 161
iii
What’s New
iMac (Early 2006)
Refer to the new procedures in the Take Apart and Troubleshooting chapters.
Logic board
•
•
•
Intel Core Processor 1.83 and 2.0 GHz
No troubleshooting LEDs
Battery is located on the top side of the logic board
AirPort Extreme and Bluetooth
•
•
Separate antennas
Separate parts: AirPort Extreme and Bluetooth boards
Memory
•
•
SO-DIMM DDR2 667 MHz, memory slot
Memory ejector levers are visibly different from the iMac G5 (iSight) models and should be
used as shown in the Take Apart section.
Ports
•
Mini-DVI video out port (for mirroring or extending the desktop)
Displays
•
LVDS (Low Voltage Differential Signaling ) displays
Power Management
•
SMC replaces SMU (See SMC Overview and SMC Reset Procedure)
Diagnostics
•
Apple Hardware Test and Apple Service Diagnostic have new interfaces and procedures (See
Diagnostics)
Troubleshooting
•
•
•
•
New procedures for troubleshooting no power (See Symptom Charts)
New procedures for troubleshooting no video (See Symptom Charts)
Updated procedures for Target Disk Mode (See Using Target Disk Mode)
Updated procedures for formatting hard drives (See Drive Formatting for Intel-based Macs.)
iMac (Early 2006) — What’s New  Service Source
Take Apart
iMac (Early 2006 20-inch)
© 2006 Apple Computer, Inc. All rights reserved.
General Information
Product View
Identifying the iMac (Early 2006 20-inch) Computer
In January 2006, a second generation iMac including a built-in iSight camera was introduced
using an Intel processor. You can identify the iMac with the Intel processor in several ways.
1.
Check the Configuration on the bottom label. On the bottom of your iMac stand, you’ll find
a label with the configuration information printed on it: The PowerPC G5 iMac computers will
list “iMac G5” in the configuration. iMac computers using Intel processors will not list G5 in
their configuration.
2.
Check the “About This Mac” window. From the Apple Menu, choose About This Mac. The
Processor listing will read the speed of the processor followed by the processor type; iMac
computers introduced in January 2006 will list an Intel processor .
iMac (Early 2006 20-inch) Take Apart — General Information What’s New
Logic board
•
•
•
Intel Core Processor 1.83 and 2.0 GHz
No troubleshooting LEDs
Battery is located on the top side of the logic board
AirPort Extreme and Bluetooth
•
•
Separate antennas
Separate parts: AirPort Extreme and Bluetooth boards
Memory
•
•
SO-DIMM DDR2 667 MHz, memory slot
Memory ejector levers are visibly different from the iMac G5 (iSight) models and should be
used as shown in the Take Apart section.
Ports
•
Mini-DVI video out port (for mirroring or extending the desktop)
Displays
•
LVDS (Low Voltage Differential Signaling ) displays
Power Management
•
SMC replaces SMU (See SMC Overview and SMC Reset Procedure)
Diagnostics
•
Apple Hardware Test and Apple Service Diagnostic have new interfaces and procedures (See
Diagnostics)
Troubleshooting
•
•
•
•
New procedures for troubleshooting no power (See Symptom Charts)
New procedures for troubleshooting no video (See Symptom Charts)
Updated procedures for Target Disk Mode (See Using Target Disk Mode)
Updated procedures for formatting hard drives (See Drive Formatting for Intel-based Macs.)
iMac (Early 2006 20-inch) Take Apart — General Information iMac (Early 2006 20-inch) Take Apart — General Information Tools Required
The following tools are required to service the computer. Note that a special access card (part
922-7172) is required to open the front bezel.
•
ESD-safe workstation and mat
•
Soft, clean towel or cloth (to protect the display and removed parts from scratches)
•
Access card to open the rear cover (part 922-7172)
•
Black stick (or other nonconductive nylon or plastic flat-blade tool)
•
Phillips #1 screwdriver
•
Phillips #2 screwdriver
•
Torx T8 screwdriver (magnetized)
•
Torx T6 screwdriver (magnetized)
•
Torx T10 screwdriver (magnetized)
•
Flat-blade screwdriver
iMac (Early 2006 20-inch) Take Apart — General Information Orientation
For most repairs, the unit should be placed screen-side up, with the bottom facing toward you.
Most photos in this manual reflect that orientation. The SO-DIMM slot is located beneath the
front bezel and is more easily accessed with the unit laying-down on a soft, clean cloth.
Serial Number Location
iMac (Early 2006) serial numbers are located on the bottom of the computer stand. The iMac
models with the Intel processor will not have G5 in the name configuration (as shown below on
the previous iMac G5 model).
iMac (Early 2006 20-inch) Take Apart — General Information 10
Safety
Warning: When the iMac (Early 2006) is under power, be aware that the power supply contains
high voltages that pose a potential hazard to your personal safety. Never work on or near the
power supply with the unit powered on, and as a further precaution always make sure the unit is
unplugged when working on it with the front bezel removed.
WARNING: HIGH VOLTAGE
Text or photographs marked by this symbol indicate that a potential hazard to your personal
safety exists from a high voltage source.
The AC/DC power supply board is a high voltage source with the unit under power, and remains
powered up whenever the system is plugged in, whether or not the system is turned on. Use
extreme caution when troubleshooting the system with the front bezel removed.
•
Disconnect power to the system before performing maintenance.
•
Don’t work alone. In the even of an electrical shock it is important to have another
individual present who can provide assistance.
•
Keep one hand in your pocket when working on any iMac (Early 2006) that is plugged
in. This will help ensure that your body does not provide a path to ground in the event
that you accidentally make contact with the line voltage.
•
Don’t wear jewelry, watches, necklaces, or other metallic articles that could present a risk
if they accidentally make contact with the power supply circuitry.
iMac (Early 2006 20-inch) Take Apart — General Information 11
Opening the Computer
Apple authorized, desktop certified technicians only should ever remove the front bezel on the
iMac (Early 2006). When the front bezel is removed, be sure to always ground yourself and follow
ESD-safe repair practices
Removing the front bezel requires using a special access card (part 922-7172) to release latches
located inside the upper corners of the front bezel. Slightly bending the upper quarter of the
access tool card will help engage the latch more securely.
As you are inserting the card to disengage the latch you should squeeze the top of the bezel,
that will help take pressure off of the latch and enable it to open easier. Note: If the bezel won’t
open, try cutting the card lengthwise into 3/4 inch or 1.5 cm strips. Insert the card on a 45º angle,
aimed toward the outer corner, and try again.
Once the card has been released it is safe to open the bezel. See the Front Bezel Take Apart
procedure for more information.
EMI Shielding
The iMac (Early 2006) enclosure is wrapped in EMI shielding that is easily torn and damaged. To
maintain a properly shielded unit, you must repair all accidental tears and cracks to the shielding
by covering them with EMI tape.
Cover nicks or tears in the EMI shielding with EMI tape.
iMac (Early 2006 20-inch) Take Apart — General Information 12
Access Door
Tools
•
•
•
Phillips #2 screwdriver
ESD-safe workstation and mat
Soft , clean towel or cloth
Preliminary Steps
Before you begin, lay the computer down so the panel is face down and the bottom is facing
you.
Part Location
iMac (Early 2006 20-inch) Take Apart — Access Door 13
Removing the Access Door
1.
Raise the stand and use a Phillips #2 screwdriver, to loosen the two captive access door
screws.
Warning: The ambient light sensor is located to the left. Don’t mistake the ambient light
sensor for a screw. Sticking a screw driver or other sharp object in the ambient light sensor
could damage the computer.
2.
Remove the access door.
Replacing the Access Door
1.
Position the access door on the rear housing over the memory compartment.
2.
Lift the stand out of the way.
3.
Use a Phillips #2 screwdriver to tighten the captive screws.
iMac (Early 2006 20-inch) Take Apart — Access Door 14
Memory
Tools
•
•
Phillips #2 screwdriver
ESD mat, soft , clean towel or cloth
Preliminary Steps
Before you begin, lay the computer down so the panel is face down with the bottom is facing
you; and remove the access door.
Part Location
iMac (Early 2006 20-inch) Take Apart — Memory 15
Removing the Memory
1.
After removing the access door, touch the metal frame around the memory compartment to
discharge any static electricity from your body.
Important: Always discharge static before you touch any parts such as the memory board.
To avoid generating static electricity, do not walk around the room until you have finished
replacing the memory.
2.
Pull the two levers in the memory compartment toward you. If a memory module is installed
in the slot, pulling the levers will dislodge it. Note: The levers are used to remove memory
not to install memory. Always install memory my hand.
a
3.
Set the memory module aside.
iMac (Early 2006 20-inch) Take Apart — Memory 16
Replacing the Memory
1.
With your fingers, insert the memory module into the memory compartment. The module
fits in the slot only one way. Push the memory module into the slot with your thumbs until
you hear a click. Note: Refer to the illustrations on the bottom of the stand for additional
memory installation information.
2.
Replace the access door on the memory compartment.
3.
Use a Phillips #2 screwdriver to tighten the captive screws on the access door.
iMac (Early 2006 20-inch) Take Apart — Memory 17
Front Bezel
Tools
This procedure requires the following tools:
•
Torx T8 screwdriver
•
Access card tool 922-7172
Preliminary Steps
Before you begin, remove the access door.
Part Location
iMac (Early 2006 20-inch) Take Apart — Front Bezel 18
Removing the Front Bezel
1.
Position unit on rear cover with the stand facing you.
2.
Tilt up the front bezel and remove four screws along the bottom.
Warning: The ambient light sensor is located in the second hole from the right. Don’t
mistake the ambient light sensor for a screw. Sticking a screwdriver or other sharp object in
the ambient light sensor could damage the computer.
3.
Locate the access card. Bending the upper quarter of the access tool card will help engage
the latch.
iMac (Early 2006 20-inch) Take Apart — Front Bezel 19
4.
This picture shows how the access tool works. Pushing the tool up the vent on the rear cover
releases the latches on the inside of the front bezel. Refer to the next step for the procedure.
5.
Start on the left side (looking from the back of the unit). As you insert the card to disengage
the latch, squeeze the top of the bezel, that will help take pressure off of the latch and
enable it to open easier. As the bezel releases, pull the bezel away from the rear housing.
Note: If the bezel won’t open, try cutting the card lengthwise into 3/4 inch or 1.5 cm strips.
Insert the card on a 45º angle, aimed toward the outer corner, and try again.
iMac (Early 2006 20-inch) Take Apart — Front Bezel 20
6.
Repeat step 5 to release the locking latch in the right corner. Again, pull the bezel away as
the card releases the latch.
7.
If the bezel won’t release, pull the bottom of the bezel out a bit and insert the access card
again.
iMac (Early 2006 20-inch) Take Apart — Front Bezel 21
8.
Repeat step 7 for the left side.
9.
Once the access card has been removed, it is safe to open the bezel. Position the unit on an
ESD mat, with the bottom facing toward you. Lift up the top of the bezel and pull it up and
slightly toward you. Caution: Make sure the memory eject levers are not protruding from the
access door when you lift the bezel up.
iMac (Early 2006 20-inch) Take Apart — Front Bezel 22
10. Swing the bezel up so you can disconnect two cables on the camera board at the top of the
bezel.
11. Remove the any kapton tape and disconnect the camera and microphone cables from the
camera board.
12. Lift the front bezel off the computer. If replacing a damaged front bezel, also remove the
camera board. Note the microphone is part of the front bezel assembly.
iMac (Early 2006 20-inch) Take Apart — Front Bezel 23
Replacing the Front Bezel
1.
Make sure the black EMI shielding along the top of the LCD panel is not in the way of the
locking mechanisms when you lower the front bezel onto the computer. Use a black stick to
press (re-stick) the EMI shielding along the top of the panel.
2.
Connect the camera and microphone cables (on the camera board) to the cables sticking
out of the top of the computer.
iMac (Early 2006 20-inch) Take Apart — Front Bezel 24
3.
Tuck the cables neatly into the channel on the rear housing.
4.
Press the memory ejector levers into the closed position.
5.
Continue to lower the font bezel down and press the top corners of the front bezel to
connect the latches. Note: Check that the latches are connected by lifting the front bezel at
each corner.
6.
Replace the four bezel mounting screws along the bottom of the computer.
7.
Replace the access door; tighten the two captive screws.
iMac (Early 2006 20-inch) Take Apart — Front Bezel 25
Camera Board
Tools
•
•
Torx T6 screwdriver
ESD mat, soft , clean towel or cloth
Preliminary Steps
Before you begin, remove the access door and front bezel.
Part Location
iMac (Early 2006 20-inch) Take Apart — Camera Board 26
Removing the Camera Board
1.
The camera board and cables are visible as you lift the front bezel off the computer.
2.
Disconnect the camera and microphone cables.
iMac (Early 2006 20-inch) Take Apart — Camera Board 27
3.
Remove the two T6 screws on the camera board.
4.
Peel back the clear mylar material to free the microphone cable from the camera board.
iMac (Early 2006 20-inch) Take Apart — Camera Board 28
5.
Remove the camera board from the front bezel.
iMac (Early 2006 20-inch) Take Apart — Camera Board 29
Replacing the Camera Board
1.
Replace the camera board on the front bezel. Carefully align and insert the camera lens until
it is snug in the bezel aperture
2.
Replace the two screws on the camera board. Route the microphone cable under the clear
mylar.
3.
Connect the camera and microphone cables.
iMac (Early 2006 20-inch) Take Apart — Camera Board 30
4.
Tuck the camera board cables neatly into the channel on the rear housing.
5.
Position the memory ejector levers into the closed position.
6.
Continue to lower the font bezel down over the pull rings (in the memory compartment)
and then lower the top corners of the front bezel so they connect with the magnetic latches.
Note: check that the latches are connected by lifting the front bezel at each corner.
7.
Replace the bezel screws along the bottom of the computer.
8.
Replace the access door; tighten the two captive screws
iMac (Early 2006 20-inch) Take Apart — Camera Board 31
Lower EMI Shield
Tools
The only tool required for this procedure is a black stick (or other nonconductive nylon or plastic
flat-blade tool).
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
Part Location
iMac (Early 2006 20-inch) Take Apart — Lower EMI Shield 32
Removing the Lower EMI Shield
1.
Carefully peel the lower EMI shield off the bottom edge of the rear housing. Use a black
stick to help peel back the shield.
2.
Gently lift the EMI shield to rest of the way to expose the other modules.
•
iMac (Early 2006 20-inch) Take Apart — Lower EMI Shield 33
Replacing the Lower EMI Shield
1.
Position the lower EMI shield over the bottom of the unit so that the holes (for the IR board
and the LED) in the shield are properly aligned.
2.
Press the sticky, edge of the EMI shield onto the bottom side of the display panel. The crease
in the EMI shield should align with the edge of the panel.
3.
Fold down the EMI shield and press it firmly over the bottom edge of the rear housing. Use a
black stick to rub out any air bubbles and ensure that the EMI shield adheres firmly and
without wrinkles along all edges.
4.
Make sure the memory eject levers are in the closed position as shown above.
5.
Replace the front bezel.
6.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — Lower EMI Shield 34
IR Board
Tools
The only tool required for this procedure is a Torx T6 screwdriver.
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
Part Location
iMac (Early 2006 20-inch) Take Apart — IR Board 35
Removing the IR Board
1.
Disconnect the IR cable and the two T6 screws on the IR board. Lift the IR board from its
mounting bracket.
2.
Using a Torx T6 screwdriver, remove the two IR board mounting screws. Remove the IR board
mounting bracket from the logic board.
iMac (Early 2006 20-inch) Take Apart — IR Board 36
3.
Note: If you are replacing the IR cable, you must remove the optical drive and disconnect the
cable from the logic board.
iMac (Early 2006 20-inch) Take Apart — IR Board 37
Replacing the IR Board
1.
If removed, route the IR cable as shown below and make sure the cable is connected to the
logic board near the optical drive and to the IR board near the memory.
2.
Install the IR board mounting bracket, IR board, and screws.
iMac (Early 2006 20-inch) Take Apart — IR Board 38
3.
Replace the lower EMI shield.
4.
Position the memory eject levers into the closed position.
5.
Replace the front bezel.
6.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — IR Board 39
LCD Display Panel
Tools
•
•
•
Torx T6 screwdriver.
Torx T10 screwdriver
Black stick (or other nonconductive nylon or plastic flat-blade tool)
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
Part Location
iMac (Early 2006 20-inch) Take Apart — Display Panel 40
Removing the Display Panel
1.
Peel the bottom of the EMI shield off the frame.
2.
Peel the EMI shield up all the way.
iMac (Early 2006 20-inch) Take Apart — Display Panel 41
3.
Using the access tool, a black stick, or your fingers, peel the black EMI tape off the right and
left sides of the panel.
4.
Using the access tool or black stick, peel back the black EMI tape stuck along the entire
length of the top panel.
iMac (Early 2006 20-inch) Take Apart — Display Panel 42
5.
Using a Torx T6 screwdriver, remove the two LVDS connector screws. Pull the black tab on the
connector to disconnect the LVDS cable from the logic board.
6.
Using a Torx T10 screwdriver, remove the four panel mounting screws.
iMac (Early 2006 20-inch) Take Apart — Display Panel 43
7.
Lift the panel up just enough to see the inverter cables on the left side (Note: this shows the
iMac G5 computer, but the procedure is the same).
8.
Disconnect the two panel-to-inverter cables on the bottom left side of the display.
Replacement Note: The cable connectors are marked with dots to indicate “right-side-up”.
iMac (Early 2006 20-inch) Take Apart — Display Panel 44
9.
Raise the panel up the rest of the way to locate the two inverter cables on the top left side of
the display. Replacement Note: The cable connectors are marked with dots to indicate
“right-side up”.
10. Lift the panel off the computer.
Note: If replacing the display panel, remove the lower EMI shield (if still attached), the display
panel mounting brackets, and the LVDS cable from the back of the display panel before
returning the module to Apple.
iMac (Early 2006 20-inch) Take Apart — Display Panel 45
Replacing the Display Panel
1.
Replace the LVDS cable on the rear of the display panel.
2.
If removed, replace the metal panel mounting brackets to each side of the display.
3.
Connect the four inverter-to-display cable connectors. Remember the connectors are keyed;
dot-side-up.
4.
Replace the display panel with four mounting screws.
5.
Connect the LVDS cable connector to the logic board and secure it with two screws.
6.
Fold the EMI tape firmly over the left, top, and right edges of the display panel. Use your
fingers or the black stick to adhere the tape firmly and rub out wrinkles. Note: If the tape
was ripped or damaged, replace the damaged EMI tape with new EMI tape
7.
Replace the lower EMI shield. Press the EMI shield along the bottom and sides of the
computer frame.
8.
Replace the front bezel.
9.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — Display Panel 46
iMac (Early 2006 20-inch) Take Apart — Display Panel 47
Speakers
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
Part Location
iMac (Early 2006 20-inch) Take Apart — Speakers 48
Removing the Speakers
1.
Using a T10 torx screwdriver, remove the screws from the left and right speakers.
Replacement Note: The longer of the two speaker mounting screws is used to secure the
left speaker; the shorter screw secures the right speaker.
2.
Note the speaker cable routing before removing the speakers. The speaker wire runs around
the AirPort Extreme card and above the heatsink.
iMac (Early 2006 20-inch) Take Apart — Speakers 49
3.
Lift the speakers up and out of the computer. See the next photo for disconnecting the
speaker.
4.
Under the right speaker, disconnect the speaker cable from the logic board.
iMac (Early 2006 20-inch) Take Apart — Speakers 50
Replacing the Speakers
1.
Connect the speaker cable to the logic board.
2.
Install the speakers and route the speaker wire above the heatsink and around the AirPort
Extreme card.
3.
Secure the right speaker with the smaller of the two mounting screws.
4.
Secure the left speaker with the longer of the two mounting screws.
5.
Replace the display panel.
6.
Replace the lower EMI shield.
7.
Replace the front bezel.
8.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — Speakers 51
iMac (Early 2006 20-inch) Take Apart — Speakers 52
iMac (Early 2006 20-inch) Take Apart — Speakers 53
AirPort Extreme Card
Tools
•
Torx T6 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
Part Location
iMac (Early 2006 20-inch) Take Apart — AirPort Extreme Card 54
Removing the AirPort Extreme Card
1.
Using a T6 torx screwdriver, remove the two screws and disconnect the antennas on the
AirPort Extreme card.
2.
The board pops up when the screws are removed. Pull the AirPort Extreme card out of the
slot in the direction of the arrow.
iMac (Early 2006 20-inch) Take Apart — AirPort Extreme Card 55
Replacing the AirPort Extreme Card
1.
Align the AirPort Extreme card with the slot on the logic board. Insert the board into the slot.
2.
Replace the two AirPort Extreme card screws.
3.
Connect the two antenna cables to the card.
4.
Replace the lower EMI shield.
5.
Replace the front bezel.
6.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — AirPort Extreme Card 56
Bluetooth Card
Tools
•
Torx T6 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Speakers
Part Location
iMac (Early 2006 20-inch) Take Apart — Bluetooth Card 57
Removing the Bluetooth Card
1.
Using a T6 torx screwdriver, remove the two T6 screws on the Bluetooth card and disconnect
the antenna from the card.
2.
Lift the card off the logic board.
iMac (Early 2006 20-inch) Take Apart — Bluetooth Card 58
Replacing the Bluetooth Card
1.
Press the Bluetooth card onto the logic board connector. Note: Make sure the card and
antenna are securely connected before installing the speakers.
2.
Connect the Bluetooth antenna to the Bluetooth card.
3.
Replace the two T6 Bluetooth card screws.
4.
Replace the speakers and speaker screws.
5.
Replace the lower EMI shield.
6.
Replace the front bezel.
7.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — Bluetooth Card 59
Optical Drive
Tools
•
•
•
Torx T10 screwdriver
Torx T6 screwdriver
Flat-blade screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
Part Location
iMac (Early 2006 20-inch) Take Apart — Optical Drive 60
Removing the Optical Drive
1.
Looking at the circles below, starting with the top circle, do the following:
Peel back the silver EMI tape going from the chassis frame to the optical drive, remove the
two T6 screws on the optical drive flex cable, disconnect the flexible cable and the optical
drive sensor cable from the logic board.
Caution: Never press down on or grasp the body of the optical drive. Pressing or squeezing
the body of the optical drive could damage the mechanism.
iMac (Early 2006 20-inch) Take Apart — Optical Drive 61
2.
Locate the black release levers on the mounting bracket. Using a flat-blade screwdriver as
shown, press straight down at the base of the release lever, while pushing the release lever
toward the center of the drive. Pressing down disengages the lever from the chassis. Repeat
the process to unhook the other release lever. Refer to step 4 for another visual aide.
3.
Repeat the release process on the second lever. Press down with the screwdriver, press the
lever inward, toward the center of the optical drive. Lift the drive out of the housing.
iMac (Early 2006 20-inch) Take Apart — Optical Drive 62
4.
This photo shows the optical drive out of the computer so you can visualize how the clips
move. Pressing down (#1) releases the clips (#2) outward from the metal chassis.
Caution: Never press down on or grasp the body of the optical drive when removing or
installing it. Pressing or squeezing the body of the optical drive could damage the
mechanism.
5.
If replacing the optical drive, use a T6 torx screwdriver to remove two flex cable screws
attaching to the optical drive. Note: Disconnect the flex cable and transfer it to the
replacement drive. Go on to the next step.
iMac (Early 2006 20-inch) Take Apart — Optical Drive 63
6.
If replacing the optical drive, disconnect the sensor cable from the optical sensor located on
the underside of the optical drive. Transfer the sensor cable to the replacement drive.
7.
iMac (Early 2006 20-inch) Take Apart — Optical Drive 64
Replacing the Optical Drive
1.
Install the flex cable to the optical drive with two T6 screws.
2.
Insert the optical drive bezel into the rear housing, lining up the bezel with the slot opening
(#1) . Be sure to align the two guide holes in the front bezel with guide posts at each end of
the drive access hole.
Push down on the mounting brackets (#2) to lock the optical drive securely into place on the
chassis.
Caution: Never press down on or grasp the body of the optical drive when installing it.
Pressing or squeezing the body of the optical drive could damage the mechanism.
iMac (Early 2006 20-inch) Take Apart — Optical Drive 65
3.
Connect the optical sensor cable to the logic board, attach the flex cable and secure it with
the T6 screws, and reattach the silver EMI tape.
4.
Replace the display panel.
5.
Replace the lower EMI shield.
6.
Replace the front bezel.
7.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — Optical Drive 66
Hard Drive
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
Part Location
iMac (Early 2006 20-inch) Take Apart — Hard Drive 67
Removing the Hard Drive
1.
Remove the two T10 screws attaching the hard drive to the DC/DC inverter board
2.
Disconnect the hard drive sensor cable from the connector on the logic board. Note the
location of the sensor on the side of the hard drive and the routing of the cable.
iMac (Early 2006 20-inch) Take Apart — Hard Drive 68
3.
The hard drive sensor is different from the optical drive sensor. The hard drive sensor can be
identified by resistor R1700. Replacement Note: Make sure to transfer the sensor to the
replacement hard drive. Use the double-stick tape enclosed with the replacement hard drive
to attach the sensor.
4.
Holding the drive by the metal bracket, pull the hard drive toward the inverter and then up
to release the hard drive mounting pins from the grommets on the chassis.
iMac (Early 2006 20-inch) Take Apart — Hard Drive 69
5.
Disconnect the hard drive power and data cables.
6.
If you are replacing the hard drive, remove the temperature sensor, mounting bracket, and
mounting pins (circled) before returning the drive to Apple. Transfer these parts to the
replacement drive.
iMac (Early 2006 20-inch) Take Apart — Hard Drive 70
Replacing the Hard Drive
1.
Attach the hard drive sensor and sensor cable to the side of the hard drive.
2.
Attach the mounting bracket and pins if they were removed. Connect the hard drive data
and power cables.
iMac (Early 2006 20-inch) Take Apart — Hard Drive 71
3.
Route the hard drive sensor cable under the metal chassis. Connect the sensor cable to the
logic board.
4.
Insert the hard drive pins into the grommets. Lower the drive into the rear housing.
iMac (Early 2006 20-inch) Take Apart — Hard Drive 72
5.
Secure the two T10 screws on the hard drive mounting bracket to the DC/DC/inverter board.
6.
Replace the display panel.
7.
Replace the lower EMI shield.
8.
Replace the front bezel.
9.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart — Hard Drive 73
Power Supply, AC/DC
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
Part Location
iMac (Early 2006 20-inch) Take Apart —Power Supply, AC/DC 74
Removing the AC/DC Power Supply
WARNING: The AC/DC power supply PCB remains powered up whenever the system is
plugged in, whether or not the system has been turned on. Use extreme caution when
troubleshooting the system with the front bezel removed.
• Don’t work alone. In the event of an electrical shock it is important to have another
individual present who can provide assistance.
• Keep one hand in your pocket when working on any iMac (Early 2006) system that is
plugged in. This will help ensure that your body does not provide a path to ground in
the event that you accidentally make contact with the line voltage.
• Don’t wear jewelry, watches, necklaces, or other metallic articles that could present a
risk if they accidentally make contact with the power supply circuitry.
1.
Using a torx screwdriver, remove the three self-tapping screws from the top and bottom left
corners of the DC-DC board. Then remove the machine screw from the bottom right corner
of the board. Replacement Note: Install the machine screw (bottom right) first when
installing the replacement board.
iMac (Early 2006 20-inch) Take Apart —Power Supply, AC/DC 75
2.
Lift the power supply up and remove the cable and connector from under the chassis. This
cable connects to the AC filter board located under the logic board. Note the routing of the
cable under the chassis.
3.
Disconnect the two power supply cables; the left cable connects to the DC/DC inverter
board and the right cable connects to the AC filter board.
iMac (Early 2006 20-inch) Take Apart —Power Supply, AC/DC 76
Replacing the AC/DC Power Supply
WARNING: The AC/DC power supply PCB remains powered up whenever the system is
plugged in, whether or not the system has been turned on. Use extreme caution when
troubleshooting the system with the front bezel removed.
• Don’t work alone. In the event of an electrical shock it is important to have another
individual present who can provide assistance.
• Keep one hand in your pocket when working on any iMac (Early 2006) system that is
plugged in. This will help ensure that your body does not provide a path to ground in
the event that you accidentally make contact with the line voltage.
• Don’t wear jewelry, watches, necklaces, or other metallic articles that could present a
risk if they accidentally make contact with the power supply circuitry.
1.
Reconnect the power supply cables.
iMac (Early 2006 20-inch) Take Apart —Power Supply, AC/DC 77
2.
Tuck the cables under the DC/DC power supply/inverter and the metal chassis as shown.
3.
Replace the power supply screws. Install the machine screw (bottom right corner) first when
installing the power supply.
4.
Replace the display panel.
5.
Replace the lower EMI shield.
6.
Replace the front bezel.
7.
Replace the access door.
iMac (Early 2006 20-inch) Take Apart —Power Supply, AC/DC 78
8.
Replace the display panel.
9.
Replace the lower EMI shield.
10. Replace the front bezel.
11. Replace the access door.
iMac (Early 2006 20-inch) Take Apart —Power Supply, AC/DC 79
Logic Board
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
Part Location
iMac (Early 2006 20-inch) Take Apart —Logic Board 80
Removing the Logic Board
1.
Disconnect the AirPort and Bluetooth antennas.
2.
Disconnect the optical cable, flex cable, and peel back the silver EMI tape from the logic
board frame.
3.
Disconnect ten cables from the connectors on the logic board.
iMac (Early 2006 20-inch) Take Apart —Logic Board 81
4.
Using a T10 torx screwdriver, remove the seven screws on the board. Replacement Note:
Always install the machine screws before installing the self-tapping screws
5.
At the top of the heatsink, remove the two screws attaching the logic board support bracket
to the chassis.
iMac (Early 2006 20-inch) Take Apart —Logic Board 82
6.
Holding the board on each side, lift it up and toward the top of the computer. Note: Remove
the memory module from the slot before returning the board to Apple
.
Important: When handling the logic board, never handle the board by the heatsink or metal
rails.
iMac (Early 2006 20-inch) Take Apart —Logic Board 83
Replacing the Logic Board
1.
Position all the logic board cables out of the way so the logic board can be placed into the
rear housing.
2.
As you lower the board into the rear housing, make sure the memory levers are lowered
through the access door opening and the logic board screw holes line up with the board..
3.
At the top of the heatsink, replace the two screws attaching the logic board support bracket
to the chassis.
iMac (Early 2006 20-inch) Take Apart —Logic Board 84
4.
Make sure the hard drive sensor and the sensor cable are attached to the side of the hard
drive. Route the sensor cable under the chassis and connect it to the logic board.
5.
Replace the optical drive sensor cable, flex cable and screws, and the silver EMI tape.
iMac (Early 2006 20-inch) Take Apart —Logic Board 85
6.
Using a T10 torx screwdriver, replace the seven screws on the board. Always install the
machine screws before installing the self-tapping screws.
7.
Connect the cables to the connectors on the logic board.
iMac (Early 2006 20-inch) Take Apart —Logic Board 86
8.
Connect the AirPort and Bluetooth antennas.
9.
Replace the speakers.
10. Replace the IR board.
11. Replace the display panel.
12. Replace the lower EMI shield.
13. Replace the front bezel.
14. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Logic Board 87
iMac (Early 2006 20-inch) Take Apart —Logic Board 88
iMac (Early 2006 20-inch) Take Apart —Logic Board 89
iMac (Early 2006 20-inch) Take Apart —Logic Board 90
AC Line Filter
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• IR Board
• Logic Board
• Hard Drive
Part Location
iMac (Early 2006 20-inch) Take Apart —AC Line Filter 91
Removing the AC Line Filter
1.
Using a torx T10 screwdriver, remove the three self-tapping screws from the power inlet and
the machine screw from the ground cable . Remove the EMI tape on the filter.
2.
Disconnect the AC filter cable from the power supply. Notice the routing of the AC filter
cable under the chassis.
3.
Lift the AC filter out of the rear housing.
iMac (Early 2006 20-inch) Take Apart —AC Line Filter 92
Replacing the AC Line Filter
1.
Install the AC power filter on the rear housing screw mounts with three self tapping screws.
2.
Install the power inlet ground cable to the chassis with a machine screw.
3.
Route the power inlet cable beneath the chassis as shown in the photo above, and connect
it to the power supply.
4.
Using the EMI tape, securely tape the top and bottom edges of the AC power inlet to the
rear housing.
5.
Replace the AC/DC power supply.
6.
Replace the hard drive.
7.
Replace the logic board.
8.
Replace the speakers.
9.
Replace the display panel.
10. Replace the IR Board.
11. Connect the antennas.
12. Replace the lower EMI shield.
13. Replace the front bezel.
14. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —AC Line Filter 93
iMac (Early 2006 20-inch) Take Apart —AC Line Filter 94
Fan, Hard Drive
Tools
•
No tools are required to remove the hard drive fan.
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Logic Board
Part Location
iMac (Early 2006 20-inch) Take Apart —Fan, Hard Drive 95
Removing the Hard Drive Fan
Once the logic board and speakers have been removed, the fan will already be disconnected. Lift
the fan straight up and out of the rear housing.
iMac (Early 2006 20-inch) Take Apart —Fan, Hard Drive 96
Replacing the Hard Drive Fan
1.
Lower the fan onto the white posts in the rear housing. Push it down snug onto the posts.
2.
Replace the logic board.
3.
Replace the speakers.
4.
Replace the display panel.
5.
Replace the IR Board.
6.
Attach the antennas.
7.
Replace the lower EMI shield.
8.
Replace the front bezel.
9.
Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Fan, Hard Drive 97
iMac (Early 2006 20-inch) Take Apart —Fan, Hard Drive 98
Fan, Optical Drive
Tools
•
No tools are required to remove the optical drive fan.
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Logic Board
Part Location
iMac (Early 2006 20-inch) Take Apart —Fan, Optical Drive 99
Removing the Optical Drive Fan
Once the logic board and speakers have been removed, the fan will be disconnected. Lift the fan
straight up and out of the rear housing.
iMac (Early 2006 20-inch) Take Apart —Fan, Optical Drive 100
Replacing the Optical Drive Fan
1.
Lower the fan onto the white posts in the rear housing, above the port openings. Route the
fan cable around the left side of the fan, through the foam gaskets. Push it down snug onto
the posts.
2.
Replace the logic board.
3.
Replace the speakers.
4.
Replace the display panel.
5.
Replace the IR Board.
6.
Replace the antennas.
7.
Replace the lower EMI shield.
8.
Replace the front bezel.
9.
Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Fan, Optical Drive 101
Fan, CPU
Tools
•
No tools are required to remove the CPU fan.
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Logic Board
Part Location
iMac (Early 2006 20-inch) Take Apart —Fan, CPU 102
Removing the CPU Fan
Once the logic board and speakers have been removed, the fan will be disconnected. Lift the fan
straight up and out of the rear housing.
iMac (Early 2006 20-inch) Take Apart —Fan, CPU 103
Replacing the CPU Fan
1.
Lower the fan onto the white standoffs in the rear housing. Push it down snug onto the
posts.
2.
Replace the logic board.
3.
Replace the speakers.
4.
Replace the display panel.
5.
Replace the IR Board.
6.
Replace the antennas.
7.
Replace the lower EMI shield.
8.
Replace the front bezel.
9.
Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Fan, CPU 104
Power Supply, DC/DC, Inverter
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Logic Board
• Hard Drive
• Power Supply, AC/DC
• Hard drive fan
Part Location
Removing the DC/DC Power Supply/Inverter
iMac (Early 2006 20-inch) Take Apart —Power Supply, DC/DC, Inverter 105
1.
Using a torx T10 screwdriver, remove the two power supply, DC-DC inverter screws
connecting the board to the rear housing. Disconnect the two cables; one going to the ACDC power supply and the other connecting to the hard drive.
2.
Remove just the circled chassis screws, one of which is the AC filter ground screw. Carefully
lift the chassis frame just enough to pull the inverter cable from under the metal chassis.
iMac (Early 2006 20-inch) Take Apart —Power Supply, DC/DC, Inverter 106
Replacing the DC/DC Power Supply/Inverter
1.
Route the inverter cable under the metal chassis frame. Check the routing of the cable so it
doesn’t get pinched under the chassis.
2.
Install the screws on the chassis frame and the AC filter ground screw.
3.
Replace the CPU fan.
4.
Connect the cables to the AC/DC power supply and to the hard drive. Replace the two
screws connecting the DC/DC power supply/inverter to the rear housing.
5.
Replace the AC/DC power supply.
6.
Replace the hard drive.
7.
Replace the hard drive fan.
8.
Replace the logic board.
9.
Replace the speakers.
10. Replace the display panel.
11. Replace the IR Board.
12. Replace the lower EMI shield.
13. Replace the front bezel.
14. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Power Supply, DC/DC, Inverter 107
Ambient Light Sensor Board
Tools
•
A black stick or equivalent tool
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Logic Board
Part Location
Removing the Ambient Light Sensor Board
iMac (Early 2006 20-inch) Take Apart —Ambient Light Sensor Board —108
1.
Remove the rubber bumper from between the chassis and the sensor board. Note: This
shows the procedure on the iMac G5 (iSight) model; the removal procedure is the same.
2.
With the rubber bumper gone, use a black stick, pry the ambient light sensor off the inside of
the rear housing. The sensor is stuck to the rear housing with double-stick tape. Note: never
poke the ambient light or you could damage the sensor board.
iMac (Early 2006 20-inch) Take Apart —Ambient Light Sensor Board —109
Replace the Ambient Light Sensor Board
1.
Press the sticky side of the ambient light sensor board to the bottom inside edge of the rear
housing.
2.
Install the rubber bumper between the back of the sensor board and the chassis.
3.
Replace the logic board.
4.
Replace the speakers.
5.
Replace the display panel.
6.
Replace the IR Board.
7.
Replace the lower EMI shield.
8.
Replace the front bezel.
9.
Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Ambient Light Sensor Board —110
Cable, Camera and IR
Tools
No tools are required to remove the camera cable.
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• IR Board
• Optical Drive
Part Location
iMac (Early 2006 20-inch) Take Apart —Camera and IR Cable 111
Removing the Camera and IR Cable
1.
Remove the two-headed end of the cable from the access hole in the upper EMI shield.
2.
Remove the tape (under the optical drive) that secures the cable to the rear housing and
disconnect the cable from the logic board. Remove the camera cable.
iMac (Early 2006 20-inch) Take Apart —Camera and IR Cable 112
Replacing the Camera and IR Cable
1.
Insert the two-headed end of the camera cable through the access hole in the upper EMI
shield.
2.
Route the camera cable as shown below. Tape the camera cable to the rear housing.
3.
Replace the optical drive, flex drive cable and screws, and optical drive sensor cable.
4.
Replace the logic board.
5.
Replace the speakers.
6.
Replace the display panel.
7.
Replace the IR Board.
8.
Replace the lower EMI shield.
9.
Replace the front bezel.
10. Replace the memory access door.
11. Replace the front bezel.
12. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Camera and IR Cable 113
Bluetooth Antenna
Tools
•
Black stick (or other nonconductive nylon or plastic flat-blade tool)
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Display Panel
• Optical Drive
• Logic Board
• Optical Drive Fan
Part Location
iMac (Early 2006 20-inch) Take Apart —Bluetooth Antenna 114
Removing the Bluetooth Antenna
1.
Carefully peel back the EMI shield from the top right inside corner of the rear housing as
shown below. Remove the piece of EMI tape securing the antenna to the chassis (#1). Peel
back just enough EMI backing to access the antenna cable (#2).
2.
Using a flat-blade screwdriver, pry the antenna off the rear housing.
3.
Pull the entire antenna cable through the opening in the EMI shielding at the top.
iMac (Early 2006 20-inch) Take Apart —Bluetooth Antenna 115
Replacing the Bluetooth Antenna
1.
Locate the antenna mounting channel inside the top right corner of the rear housing, and
position the antenna in the channel. Compress the sticky side of the antenna to the housing
until securely fastened.
2.
Route the antenna cable and insert the connector end of the cable through the access hole
in the EMI skirt.
3.
Secure the antenna cable at the top with EMI tape.
4.
Carefully replace the EMI shield at the top. Using a black stick, work out all wrinkles and
bubbles until the EMI tape is smooth and tight.
5.
Route the antenna wire on top of the EMI shielding, along the right side of the rear housing.
6.
Replace the optical drive.
7.
Replace the CPU fan
8.
Replace the logic board.
9.
Connect the Bluetooth antenna.
10. Connect the IR cable.
11. Connect the AirPort antenna.
12. Replace the speakers.
13. Replace the display panel.
14. Replace the lower EMI shield.
15. Replace the front bezel.
16. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Bluetooth Antenna 116
iMac (Early 2006 20-inch) Take Apart —Bluetooth Antenna 117
AirPort Antenna
Tools
•
Black stick (or other nonconductive nylon or plastic flat-blade tool)
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Speakers
• Display Panel
• Optical Drive
• Logic Board
• Hard Drive Fan
Part Location
iMac (Early 2006 20-inch) Take Apart —Wireless Antenna 118
Removing the AirPort Extreme Antenna
1.
Carefully peel back the EMI tape (off the chassis) and the EMI backing from the top left inside
corner of the rear housing as shown below. Peel back just enough EMI backing to access the
antenna board. WIth a black stick pry the antenna off the rear housing.
2.
Remove two pieces of tape that secure the antenna cable to the rear housing (near the
power on LED, in the bottom left corner). Pull the antenna cable through the access hole in
the EMI shield at the top, near the antenna board.
iMac (Early 2006 20-inch) Take Apart —Wireless Antenna 119
Replacing the AirPort Extreme Antenna
1.
Locate the antenna mounting channel inside the left corner of the rear housing, and position
the antenna in the channel. Compress the sticky side of the antenna to the housing until
securely fastened.
2.
Route the antenna cable through the EMI shield and on top of the EMI.
3.
Secure the extra length of antenna cable to the housing with two pieces of tape.
4.
Replace the CPU fan.
5.
Replace the logic board.
6.
Replace the DC-DC board.
7.
Replace the DC power supply.
8.
Replace the speakers.
9.
Replace the IR Board.
10. Replace the AirPort Extreme board.
11. Replace the Bluetooth board.
12. Replace the display panel.
13. Replace the lower EMI shield.
14. Replace the front bezel.
15. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Wireless Antenna 120
iMac (Early 2006 20-inch) Take Apart —Wireless Antenna 121
Clutch Mechanism
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Optical Drive
• Logic Board
• CPU Fan
Part Location
iMac (Early 2006 20-inch) Take Apart —Clutch 122
Removing the Clutch
1.
Remove the EMI tape attached along the top and bottom sides of the clutch mechanism
cover. After removing the tape, pull the cover straight off the clutch.
2.
Peel back the EMI tape on top of the mechanism. Using a torx T10 screwdriver, remove the
four clutch mounting screws.
iMac (Early 2006 20-inch) Take Apart —Clutch 123
3.
Stand up the unit, to access the clutch-to-stand mounting screws.
4.
Using a T10 torx screwdriver, remove the seven clutch-to-stand screws. Separate the
mechanism and the stand from the rear housing.
iMac (Early 2006 20-inch) Take Apart —Clutch 124
Replacing the Clutch
1.
Make sure the stand is erect and the end of the stand is inserted through the mounting hole
in the rear housing.
2.
Position the clutch on the stand, with the clutch springs at bottom. Install the seven long,
clutch-to-stand mounting screws.
3.
Adjust the clutch so that its chassis mounting holes align, and install the four screws that
secure the clutch to the chassis.
4.
Replace the silky EMI tape on top of the mechanism, press it into place.
5.
Replace the metal mechanism cover.
6.
Replace the EMI tape along the top and bottom of the mechanism cover. Make sure the
spring clip on the right side of the mechanism cover is attached to the mechanism cover.
7.
Replace the CPU fan.
8.
Replace the logic board.
9.
Replace the speakers.
10. Replace the display panel.
11. Replace the IR Board.
12. Replace the lower EMI shield.
13. Replace the front bezel.
14. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Clutch 125
Chassis
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Optical Drive
• Logic Board
• CPU Fan
• AC Line Filter
• Hard drive
• Power supply, AC/DC
• Clutch
• Stand
iMac (Early 2006 20-inch) Take Apart —Chassis 126
Part Location
Removing the Chassis
Using a T10 screwdriver, remove 12 self-tapping screws from the chassis, and remove the chassis
from the rear housing.
iMac (Early 2006 20-inch) Take Apart —Chassis 127
Replace the Chassis
1.
Position the chassis on the rear housing as shown and install 12 self-tapping mounting
screws.
2.
Replace the clutch mechanism.
3.
Replace the AC line filter.
4.
Replace the AC/DC power supply.
5.
Replace the hard drive.
6.
Replace the optical drive.
7.
Replace the hard drive and optical drive fans (if removed).
8.
Replace the CPU fan.
9.
Replace the logic board.
10. Replace the speakers.
11. Replace the display panel.
12. Replace the IR Board.
13. Replace the lower EMI shield.
14. Replace the front bezel.
15. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Chassis 128
Rear Housing
Tools
No tools are required to remove the rear housing.
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Display Panel
• Speakers
• Hard drive
• Optical Drive
• Logic Board
• Power supply, AC/DC
• Power supply, DC/DC, Inverter
• CPU Fan
• AC Line Filter
• Optical fan
• Hard drive fan
•
Camera cable
• Bluetooth antenna
• Clutch
• Stand
• Ambient Light Sensor
• Chassis
iMac G5 (20-inch iSight) Take Apart —Chassis 129
Part Location
Removing the Rear Housing
Using a T10 torx screwdriver, remove 12 self-tapping screws from the chassis, and remove the
chassis from the rear housing. Note: the EMI shield is part of the rear housing.
iMac G5 (20-inch iSight) Take Apart —Chassis 130
Replace the Rear Housing
1.
Position the chassis on the rear housing as shown and install 12 self-tapping mounting
screws.
2.
Replace the clutch mechanism.
3.
Replace the stand.
4.
Replace the AC line filter.
5.
Replace the AC/DC power supply.
6.
Replace the hard drive.
7.
Replace the optical drive.
8.
Replace the hard drive and optical drive fans (if removed).
9.
Replace the CPU fan.
10. Replace the logic board.
11. Replace the speakers.
12. Replace the display panel.
13. Replace the IR Board.
14. Replace the lower EMI shield.
15. Replace the front bezel.
16. Replace the memory access door.
iMac G5 (20-inch iSight) Take Apart —Chassis 131
Stand
Tools
•
Torx T10 screwdriver
Preliminary Steps
Before you begin, remove the following:
• Access door
• Front bezel
• Lower EMI shield
• Speakers
• IR Board
• Display Panel
• Logic Board
• CPU Fan
• Clutch
Part Location
iMac (Early 2006 20-inch) Take Apart —Stand 132
Removing the Stand
1.
Stand up the unit, to access the clutch-to-stand mounting screws.
2.
Using a T10 torx screwdriver, remove the seven clutch-to-stand screws. Separate the
mechanism and the stand from the rear housing.
iMac (Early 2006 20-inch) Take Apart —Stand 133
Replacing the Stand
1.
Make sure the stand is erect and the end of the stand is inserted through the mounting hole
in the rear housing.
2.
Position the clutch on the stand, with the clutch springs at bottom. Install the seven long,
clutch-to-stand mounting screws.
3.
Adjust the clutch so that its chassis mounting holes align, and install the four screws that
secure the clutch to the chassis.
4.
Replace the silky EMI tape on top of the mechanism, press it into place.
5.
Replace the metal mechanism cover.
6.
Replace the EMI tape along the top and bottom of the mechanism cover. Make sure the
spring clip on the right side of the mechanism cover is attached to the mechanism cover.
7.
Replace the CPU fan.
8.
Replace the logic board.
9.
Replace the speakers.
10. Replace the display panel.
11. Replace the IR Board.
12. Replace the lower EMI shield.
13. Replace the front bezel.
14. Replace the memory access door.
iMac (Early 2006 20-inch) Take Apart —Stand 134
iMac (Early 2006 20-inch) Take Apart —Stand 135
 Service Source
Troubleshooting
iMac (Early 2006 20-inch)
© 2006 Apple Computer, Inc. All rights reserved.
General Information
Serial Number Location
iMac (Early 2006) serial numbers are located on the bottom of the computer stand.
Power On Self Test (POST)
Intel-based Macs such as the iMac (Early 2006) rely on a combination of tones and blinking LEDs
to display Power On Self Test (POST) error codes.
If the computer detects out-of-specification memory or no RAM installed, the screen will be black
and the power LED on the front of the computer will blink once a second to indicate bad or no
RAM. Bad RAM can include physically damaged, the incorrect type, or not present.
If the RAM is good enough to pass the POST test but it is marginal and cannot be used by the
operating system, the computer will show a gray screen, three tones will sound and the power
LED on the front of the computer will blink three times, pause, and repeat until the computer is
turned off.
The solution to both these situations is to install known good memory.
iMac (Early 2006 20-inch) Troubleshooting — General Info 137
DDR Memory
The iMac (Early 2006) computer has two SDRAM slots in the bottom of the computer. The iMac
ships from the factory with at least 512 MB of DDR2 SDRAM installed into the top slot. (The
computer may come with more RAM in the top slot or RAM in the bottom slot, depending on
how the computer was ordered from Apple.)
The maximum amount of RAM you can install in the iMac is 2 GB total (a 1 GB SO-DIMM in each
of the two slots). You can use small-outline dual inline memory modules (SO-DIMMS) of 512 MB or
1 GB that meet all of these criteria:
•
- PC2-5300
•
- unbuffered
•
- nonparity
•
- 200-pin
•
- 667 MHz DDR2 SDRAM
NOTE: DIMMs with any of the following features are NOT supported in this iMac:
•
- registers or buffers
•
- PLLs
•
- ECC
•
- parity
•
- EDO RAM
iMac (Early 2006 20-inch) Troubleshooting — General Info 138
Symptom Charts
How to Use the Symptom Charts
The Symptom Charts included in this chapter will help you diagnose specific symptoms related
to the product. Because cures are listed on the charts in the order of most likely solution, try
the cures in the order presented. Verify whether or not the product continues to exhibit the
symptom. If the symptom persists, try the next cure.
Note: If a cure instructs you to replace a module, reinstall the original module before you
proceed to the next cure.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 139
Power Issues
No Power.
The iMac (Early 2006) will not turn on. The display remains black and there are no sounds from
the fans or drives.
1. Verify the power outlet is good. Plug a different device into the socket to ensure there is power,
or plug the iMac into another outlet. Does the iMac power on now?
Yes. Resolved. Bad outlet.
No: Go on to the next step.
2. Check the power cord. Use a known good power cord. Does the iMac power on now?
Yes: Your power cord has failed. Replace the AC power cord.
No: Go on to the next step.
3. Check the connection of the power cord on both ends. Verify that the power cord is securely
plugged into both the AC outlet and back of the computer. Does the iMac power on now?
Yes: You may have a loose fit to your power cord. Replace the AC power cord and test.
No: Go on to the next step.
4. Plug a bus powered FireWire device in like an iPod using a FireWire cable or other FireWire
drive or device with a power LED. Does the iPod show charging or the FireWire device show a
power LED on?
Yes: The AC Power Inlet is good. Go on to the next step.
No: AC power is not being detected. If you’ve verified the outlet and power cord, replace the
AC Power Inlet.
5. Plug a bus powered USB device into the USB ports on the rear of the computer like a keyboard,
iPod Shuffle or USB 2.0 iPod using a USB cable and press the power button. Does the iPod show
power or the keyboard caps lock LED light?
Yes: The Power Supply is functioning. Go on to the next step.
Yes, but only for a moment: The Power Supply cannot maintain power; replace the Power
Supply.
No: The Power Supply has failed. Replace the Power Supply.
6. At this point in the Power On process, you should hear a boot chime and see the front LED on
the computer light up. When the main logic board and LCD panel communicate to deliver video,
the front LED should go out. Does the Front LED go off?
Yes: The LCD and main logic board have communicated. If there is no picture on the display,
follow No Video troubleshooting.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 140
No: Your logic board is not communicating with LCD panel. Open the unit and re-seat the
TMDS cable and test again. If the issue persists, replace the main logic board.
Audible buzzing, whining, or ticking noise
The iMac (Early 2006) contains several mechanical devices such as motors and fans that may
make audible buzzing, ticking, or whining noises when they are operating in a normal manner.
The sounds will vary depending on how the system is used.
When troubleshooting abnormal noises try the following:
1.
Verify that the computer is running a supported version of the Mac OS X operating system.
If an earlier version of the operating system has been installed then the fans may run at
excessive speeds.
2.
Determine that this noise is related to the computer by removing and shutting down all
other devices in the vicinity of the computer that could be causing a sound.
3.
Eject any media inserted into the optical drive. The optical drive will make a variety of normal
sounds when accessing the optical media.
4.
Quit all applications and test the computer again. Processor intensive applications may cause
the fans to run at a higher RPM and therefore be more audible.
5.
Boot to Apple Service Diagnostic v. 3S100 or later and select the EFI test suite by holding
down the D key during startup. The diagnostic tests fan speeds and thermal sensor
functionality. Should tests fail, replace any parts indicated by the diagnostic.
6.
Reboot the computer and check the computer again. If the noise persists and is unusually
loud, contact Apple Technical Support.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 141
No Video
The iMac (Early 2006) will turn on but there is No Video on the display.
The boot chime can be heard, a white LED appears on the front bezel and sounds from the fan or
drive activity can be heard, but the display has no picture or color.
1. Check if the computer is sleeping. Press the space bar to wake the computer from sleep mode.
Did the computer wake from sleep?
Yes: Put the computer to sleep from the Apple menu and wake the computer again to test.
Check Energy Saver setting to see when the computer has been designated to sleep.
No: Continue to next step.
2. Reset your computer’s PRAM (Parameter RAM):
- If your iMac is on, turn it off by holding the power button until the unit powers off. You
should hear the fans go quiet.
While the computer is off, with your left hand, hold down the Apple key, the Option key
next to it, and the letter “R” key on the keyboard. When you have these keys all pressed
down, push the power button with your right hand and then quickly move that hand
to hold down the letter “P” on the keyboard. Keep these four keys pressed while the
computer starts up.
Make sure you hold down the four keys (P - R - Apple - Option) while the computer is
starting up. When you hear the computer’s start up chime for the second time, you can
let go of the keys on the keyboard.
If you didn’t hear at least two startup chimes, go to the top of this section and begin
again. It’s important that you hear two startup chimes when performing this procedure.
This indicates that you have successfully reset the computer’s PRAM (Parameter RAM).
4. Does the computer display video after successfully resetting the computer’s PRAM?
Yes: Restart the computer from the Apple menu and make sure the computer is now
working correctly.
No: Continue to next step.
5. Make sure the machine is powered off; power off the machine by holding in the Power Button
on the rear of the machine. Turn on the machine. Observe the white LED on the front bezel
during startup; it should go out after a few moments. Did the LED go off?
Yes: If the LED went off, this indicates that the main logic board has communicated with the
LCD display for video signal and your main logic board should be good. You can confirm by
connecting an external monitor and checking to see that you have video out. Go to Step 8.
No: Continue with the next step to reset system power management
6. Reset the SMC (Formerly SMU).
- Turn off the computer by choosing Shut Down from the Apple menu, or by holding the
power button until the computer turns off.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 142
-
Unplug all cables from the computer, including the power cord.
Wait 10 seconds.
Plug in the power cord while simultaneously pressing and holding the power button on
the back of the computer.
Let go of the power button.
Press the power button once more to start up your iMac.
After resetting the SMC (Formerly SMU), does front LED go off after a few moments now?
Yes: Press and hold the power button until the computer powers off. Start the computer
again and confirm that front LED is reliably going off. If the computer still has no video but
the LED is reliably going off, continue with step 8.
No: Go to the next step.
7. Unplug the iMac and remove the SDRAM. Replace with known good SDRAM. Plug the iMac
back in and power the unit on. Does the front LED go off after a few moments now?
Yes: Replace the original SDRAM and test again. If the front LED does not go off with the only
the original SDRAM installed, replace the SDRAM. If the LED is now reliably going off after a
few moments, but yet you still do not have any video, go to step 8.
No: If the LED remained on, the main logic board is not communicating with the LCD panel
to generate video. Replace the main logic board.
8. With the LED going off, you may have a No Backlight condition or an LCD failure. In a dim room,
turn the display at an angle to you and look closely at the display. Is the display completely black
or can you see a dim, purplish light or glow to the display?
- Completely black: Replace the inverter
- Dim purplish light or glow: Replace the LCD panel.
Display is tinted another color.
1.
Reset the parameter RAM. Press the Command-Option-P-R keys. When you keep all the keys
held down, you will hear the startup chime over and over again (about every ten seconds)
until you let go. After you hear the second chime, you can let go of the keys.
Does the computer display video after successfully resetting the computer’s PRAM?
Yes: Problem resolved. Restart the computer from the Apple menu and make sure the
computer display is no longer tinted another color.
No: Continue to the next step.
2.
Connect an external monitor to the mini-VGA port. Does the external display exhibit the
same color tinting?
Yes: Replace the logic board.
No: Check the TMDS cable connection. If connected and same color tinting persists, replace
the TMDS cable. Does color tinting persist after changing the TMDS cable?
Yes: Replace the LCD display panel.
No: Problem solved. Restart the computer from the Apple menu and make sure the
computer display is no longer tinted another color.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 143
Display
When displaying a single color over the screen area, the LCD panel shows one or more pixels
that are not properly lit
Active-matrix LCD technology uses rows and columns of addressable locations (pixels) that
render text and images on screen. Each pixel location has three separate subpixels (red, green,
and blue) that allow the image to be rendered in full color. Each subpixel has a corresponding
transistor responsible for turning the subpixel on or off.
There are typically millions of these subpixels on an LCD display. For example, the LCD panel used
in the Apple Cinema HD display is made up of 2.3 million pixels and 6.9 million red, green, and
blue subpixels. Occasionally, a transistor does not work perfectly, which may result in the affected
subpixel being turned on (bright) or turned off (dark). With the millions of subpixels on a display,
it is quite possible to have a low number of faulty transistors on an LCD. Therefore, a certain
number of subpixel anomalies is considered acceptable. Rejecting all but perfect LCD panels
would significantly increase the retail price for products using LCD displays. These factors apply
to all manufacturers using LCD technology—not just Apple products.
To determine whether or not the display has an acceptable number of pixel anomalies, follow the
steps below:
1.
Set the display image to one of the following colors: all-white display, all-red display, all-green
display, or all-blue display.
2.
Using a jeweler’s loupe, pocket microscope, or other magnifying device, identify and count
each subpixel anomaly:
• Bright subpixel anomaly = subpixel that is always on
• Dark subpixel anomaly = subpixel that is always off
3.
Important: Check the number of subpixel anomalies with the following chart:
LCD Size
(inches)
17 to 20
Acceptable Number of Subpixel
Anomalies
Replace the Display
Bright
Dark
Both
Bright
Dark
Both
up to 4
up to 6
up to 8
5 or more
7 or more
9 or more
4.
If the number of subpixel anomalies exceeds the acceptable number listed in the chart,
replace the LCD panel.
5.
If the number of subpixel anomalies is acceptable, explain to the customer that the pixel
anomalies are within specifications, and no repair is necessary.
Important: Do not release the specifications to customers. Instead, inform them that a
certain number of subpixel anomalies is considered acceptable, and these factors apply to all
manufacturers using LCD technology—not just Apple products.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 144
Hard Drive
Flashing question mark, or an alternating question mark and Mac OS (face or a
folder)
Note: When troubleshooting hard drive problems it is a good idea, if possible, to back up any
important data. Some troubleshooting steps may require erasing the contents of the hard drive.
1.
Boot from the system CD that came with the computer, and open Disk Utility. Does the hard
drive show in Disk Utility?
Yes: Run Repair Disk and Repair Permissions to correct any directory and permissions issues.
Go on to Step 2.
No: Go to Step 3.
2.
Did Disk Utility successfully repair directory or permissions?
Yes: Restart the computer to the hard drive. Go on to Step 3.
No: Go to Step 3.
3.
Did the computer successfully start to the internal Hard Drive?
Yes: Run Apple Hardware Test 3A100 or later for this machine and return to the customer if it
passes.
No: Boot the machine to Apple Hardware Test 3A100 or Apple Service Diagnostic 3S100 (or
later).
4.
Did the machine successfully boot to the Diagnostic?
Yes: Run the test suites. No: Make sure you’re using the correct version of the Diagnostic, and that the disc is able to
boot another machine that it supports. If so, then try booting from an external optical drive.
If this is successful, you should replace the optical drive and retest the machine booting to
the diagnostic disc. 5.
Did the tests pass?
Yes: Reinstall the System Software that came with the computer and test. No: Replace the component (s) indicated by the test results. Hard Drive Issues
Note: The following information is for Intel-based and PPC Macintosh drive compatibility
Drives to be used in booting Intel-based Macintosh hardware should be formatted and
•
partitioned with an Intel-based Macintosh disk utility running on Intel-based Macintosh
hardware. That should ensure you get the correct default partition map and structure for
reliable booting.
Intel-based Macintosh CPUs in Target Disc Mode will only mount on PPC machines running
•
Mac OS X 10.4 or later, and may show one contiguous partition rather than separate
partitions on the host machine.
Always make sure to use the OS that came with the machine if you need to reinstall software
•
(ask the customer for the discs if necessary), and the diagnostics specifically designated for
that hardware.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 145
System hangs during normal startup process
1.
Boot from the system CD that came with the computer and see if the hard drive mounts on
the desktop.
2.
Using Drive Setup, reinstall the system software drivers for the hard drive.
3.
Using Drive Setup, reinitiation the hard drive.
4.
Check all cable connections to and from the hard drive.
5.
Replace the hard drive data cable.
6.
Replace the hard drive.
7.
Replace the logic board.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 146
Optical Drive
CDs or DVDs don’t show up on the Desktop.
1.
Select Preferences from the Finder menu and make sure the option to show CDs, DVDs and
iPods is checked: in the General window as shown below.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 147
2.
Select System Preferences from the Apple menu and open the CDs & DVDs preferences
window. Make sure that audio CDs are set to launch iTunes and movie DVDs set to launch
DVD Player when those media are inserted, as shown below.
3.
Check that the drive can read discs normally. Insert an audio CD and check whether it shows
up on your desktop or launches iTunes.
Does the audio CD mount on the desktop or in iTunes?
Yes: The drive seems to read CD discs okay. Go on to Step 4.
No: Make sure the disc is readable by other computers. Try other CD discs. If none mount or
no audio CDs launch iTunes, replace the optical drive.”
4.
Eject the audio CD and insert the iMac Software Install and Restore DVDs that came with the
customer’s computer, or insert a DVD movie.
Does this disc show up on the desktop, or does the movie launch DVD Player? Yes: The computer is reading CD and DVD media. This may be related to a specific disc or
discs the customer is using and you should examine those discs.
No: The optical disc is reading CD media, but not DVD media. Try other DVD discs. If none
mount or movie DVDs do not launch DVD Player, replace the optical drive flex cable.
5.
If after replacing the optical drive flex cable the drive still won’t mount any optical media,
replace the optical drive. If the issue persists, then replace the logic board.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 148
The computer won’t burn discs.
1.
Check whether the drive can read CDs and DVDs normally. Perform the steps above for “CDs
or DVDs don’t show up on the Desktop.”
2.
Try a test burn by creating a Burn Folder, as follows.
• In the Finder, choose “New Burn Folder” from the File menu.
• Open the Burn Folder, drag an item inside for testing, and click “Burn” in the upper right
corner of the window.
• When prompted, insert a blank disc and follow the dialog instructions.
Does the disc burn successfully (problem solved), fail with an error, or is the disc ejected?
3.
If the disc fails to burn with an error, check for these error messages.
Unknown Error -2147352480. See Knowledge Base article 25480 and 25750 for more
information.
Buffer underrun error. See Knowledge Base articles 25480 and 25750 for more information.
Unknown Error. If you see “Unknown Error” without “-2147352480”, you will want to see
Knowledge Base article 152224 for more information.
4.
If the blank disc is ejected, try another blank disc. If the issue persists, try another brand and
speed of blank media; if you’re using blank CD media, see if this happens with blank DVD
media. If the drive consistently rejects all blank media, or only rejects blank CD media while
accepting blank DVD media or vice versa, replace the optical drive flex cable and test.
Does the drive successfully burn to disc after replacing the optical flex cable?
Yes: Problem solved.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 149
No: Replace the optical drive. Does it burn correctly now?
Yes: Problem solved.
No: Replace the logic board.
Discs won’t insert.
1.
Is there a disc already in the drive?
Yes: Eject the disc before inserting another. Refer to Knowledge Base article 106752,
“Macintosh: How to Eject a Disc When Other Options Do Not Work”. If none of these options
will eject the disc, you may have to disassemble the drive to recover the disc. See Knowledge
Base article 86382 - Macintosh: How to Remove a Stuck Disc From a Slot-Loading Drive.
No: Reseat the optical drive. Perform the “Optical Drive” procedure in Take Apart to reseat the
drive in the mounting aperture and reconnect the optical flex drive cable connector.
2.
After reinstalling the optical drive, can you now insert a disc?
Yes: Issue resolved. Run diagnostics and return the system to the customer. No: Replace the optical drive flex cable. Yes: Problem solved. Run diagnostics and trying inserting a disc again.
3.
After replacing the optical drive flex cable, can you insert a disc now?
Yes: Issue resolved. Run diagnostics and return the system to the customer. No: Replace the optical drive.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 150
Optical disc constantly ejects
1.
Disconnect all peripheral devices, especially the mouse in cases where the disc is constantly
ejecting. Retest. If the issue is resolved, reconnect peripherals one-at-a-time until faulty
peripheral is identified.
2.
Try cleaning the disc. If the disc is dirty or scratched, it may not mount.
Is the issue resolved?
Yes: Problem solved.
No: Try a different disc. If the issue persists, go on to the next step.
3.
Boot from Apple Hardware Test (hold down the “D” key at startup). If you can boot to this
volume, run the Quick and Extended tests.
Does the unit pass the tests?
Yes: Restart to the internal hard drive and test again.
No: Replace the component (s) indicated by the test results. If you cannot boot to Apple
Hardware Test because it ejects, go on to step 4.
4.
Boot from the system install DVD (use Startup Manager, hold down the Option key at
startup). If you can boot from this volume, perform an Archive and Install with the Install
DVD that came with the computer and test.
Is the issue resolved?
5.
Yes: Problem solved.
No: If you cannot boot to Apple Hardware Test or to the Install DVD because they eject,
reseat the optical drive flex cable and retest.
6.
Replace the optical drive flex cable.
7.
Replace the optical drive.
8.
Replace the logic board
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 151
Fan Sound
Loud fan noise coming from inside the computer
The iMac G5 (20-inch iSight) has a trio of fans that circulate air throughout the system. It also
includes temperature sensors, and advanced thermal software that spins the fans fast or slow as
needed. As the system usage increases, the fans will adjust their speed using advanced thermal
software to meet the cooling needs of the system.
Under normal conditions, rotating fans will make a slight hum that varies in relationship with
their rotational speed and the amount of air that they are moving. In addition, the normal
functioning of the hard drive and optical drive will generate additional whirring and scratching
sounds that may be audible. All of these sounds are normal and do not indicate a failure with
your computer.
To begin troubleshooting a possible fan issue, we need to qualify the sound that you’re
experiencing.
1.
Does the sound occur only under specific light/heavy usage conditions?
Yes: CPU intensive applications such as iTunes, Garage Band, DVD Player, etc., or two or more
applications open at once will cause the fans to run at an increased rate making them more
noticeable. If the sound only occurs when one or more of these applications is running, this
is normal.
No: If the sound isn’t affected by CPU intensive application it may be due to other factors. Go
on to the next step.
2.
Is the sound always present, or does the sound vary?
The sound is always present: The normal functioning of the hard drive and optical drive will
generate additional whirring and scratching noises that may be audible. Check whether this
sound is related to one of the components. Go to step 4.
The sound varies: Under normal conditions rotating blowers will make a slight hum that
varies in relationship with their rotational speed and the amount of air that they are moving.
Let’s see if this is indeed the case. Go to Next Step.
3.
Are the fans making a normal humming sound that increases/decreases in relation to
processor usage? As the fans increase their speed to cool the system the sound level will
increase.
Launch the Activity Monitor application included with Mac OS X in the Utilities folder to
determine whether the noise corresponds with heavy usage of the CPU. Does fan activity
increase / decrease with the CPU Usage graph in Activity Monitor? Check by running CPU
intensive applications such as iTunes.
Yes: This is normal operation and none of the fans require replacement.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 152
No: If the fan activity does not coincide with CPU usage, the sound you’re hearing may not
be fan activity. Go to the Next Step.
4.
The normal functioning of the hard drive and optical drive will generate additional whirring
and scratching noises that may be audible. We can isolate these noises by booting the
computer to the iMac Install Mac OS X Install Disc 1.
- Place the disc in the drive, and restart your machine while holding down the “C” key as the
machine starts up.
- Once at the Installer window, choose Open Disk Utility from the Installer Menu.
- Once Disk Utility is open, select the system’s hard drive and on the toolbar choose
Unmount. Note: if the drive has multiple partitions, unmount each of these partitions.
This will spin down the hard drive. The optical drive will also be busy at this time; wait a
moment for the optical drive to spin down also and then listen to the machine.
Is the sound still present?
Yes: With the hard drive and optical drive inactive, all you should be hearing are the fans
in the machine. While booted to the CD, these fans should be running at a lower level
since CPU activity is low with both drives inactive. Fan sound that includes objectionable
ticking, whistling, or squealing may require further investigation and/or replacement of the
particular fan. Go on to the next step.
No: The normal functioning of the hard drive and optical drive will generate additional
whirring and scratching sounds that may be audible. All of these sounds are normal and do
not indicate a failure with the machine. If you wish to check the health of the hard drive, see
article 152349, “Replacing a disk before it fails.”
5.
Shut down the computer, remove the power cord and any other connected cables, and
remove the access door, front bezel, and EMI shield.
Stand up the computer, plug it in, and start it up by pressing the external power button.
As the machine starts up, listen carefully to each of the three fans, and see if you can locate
the fan from which the objectionable ticking, whistling, or squealing sound is coming. The
CPU fan is the left-most fan, the hard drive fan is in the center, and the optical drive fan is on
the right.
Can you pinpoint the fan making the sound?
Yes: Replace the noisy fan.
No: If you can hear an objectionable ticking, whistling, or squealing sound, but you cannot
identify the source of the sound, contact Apple Technical Support.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 153
Fans are running at a constant high speed
If the fans on the system are running at a constant high speed, or ramp very quickly to high
speed and do not vary once this speed is reached, the fans are most likely receiving incorrect
thermal input. Follow these steps:
1.
Reset the SMC and then test to see if the fans still exhibit the issue.
2.
Boot to Apple Service Diagnostic v3S100 EF1 tests. This will test the fans and thermal input of
the sensors. If the tests fail, replace the component (s) indicated by the test.
3.
Verify that the hard drive temperature sensor cable, and the optical drive temperature
sensor cable are plugged in correctly. If necessary, replace the hard drive and optical drive
temperature sensor cables.
4.
Replace the hard drive and optical drive temperature sensors.
5.
Replace the hard drive.
6.
Replace the logic board.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 154
AirPort/
Not able to connect wirelessly with AirPort
1. From the Apple menu, choose About this Mac.
2- Click on More Info. System Profiler should open.
3- In System Profiler, in the column on the left, look under Network for a line called “AirPort Card”.
Select that line.
4- Does the section to the right say “No Information Found”?
Yes: The computer doesn’t realize it has an AirPort card installed. Go to step. 5
No: The iMac recognizes that it has an AirPort card installed. Go to step 6.
5- Remove the front bezel, lower EMI shield, and two card mounting screws. and reseat the
AirPort card. Re-install the two card mounting screws and check System Profiler again to see if
the computer sees the AirPort card. Does it recognize the card now?
Yes: Problem solved. Replace the lower EMI shield and front bezel and re-test the system to
verify that the original symptom is resolved.
No: Replace the AirPort card. Refer to the Take Apart - Logic board procedure for
replacement instructions. If the issue persists after replacing the AirPort card, replace the
logic board..
6- Now that we know the iMac recognizes the AirPort card, check the antenna. If the antenna is
not plugged in all the way, you may have very short AirPort range.
7- Remove the access door, front bezel, lower EMI shield, and right speaker, and the two AirPort
card mounting screws . Disconnect the card, turn it over and reconnect the antenna cable
connectors to the card. Make sure the antenna lead is firmly seated. Replace the card and other
components and re-test.
8- If the antenna lead is plugged in properly and the AirPort card is recognized but the problem
persists, there are a number of other things that could cause issues with wireless networking.
Refer to Knowledge Base document 106858 for more networking information.
9- Replace the AirPort card. Refer to Take Apart/Logic Board.
10- Replace the AirPort antenna. Refer to Take Apart/AirPort Antenna.
11- Replace the logic board. Refer to Take Apart/Logic Board.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 155
IR Remote
Remote won’t communicate with system applications such as iTunes or iPhoto, or with the
optical drive.
Make sure of the following when using the Apple Remote:
•
You are within 30 feet of the front of the computer.
•
You have an unobstructed line-of-sight to the front of the computer.
•
You are pointing the lens end of the Apple Remote directly at the front of the computer.
•
The computer is powered on and awake.
•
The “Disable remote control infrared receiver” checkbox in the Security pane of System
Preferences is NOT checked.
•
Make sure the active application works with Apple Remote. Apple Remote uses Front Row,
and from Front Row it can access DVD Player, iPhoto, iTunes, and QuickTime Player.
•
Make sure the remote is paired with the computer. Access the System Preferences/Security
pane and check “Unpair” if available. Close the Security pane, and re-pair the Apple Remote
with the computer. See Knowledge Base article 302545.
1.
Use a digital camera to test your Apple Remote.
If you have a digital camera or DV camera with an LCD display, you can use it to see if your
Apple Remote is emitting a signal. Infrared beams are invisible to the human eye, but most
digital cameras and video cameras use Charged-Coupled Device (CCD) chips or image
sensors that are sensitive to infrared light.
To use a camera to test your Apple Remote, follow these steps:
• Turn on your digital camera or DV camera and remove any lens cover.
• Point your Apple Remote toward the camera lens.
• Press and hold the Menu button on the remote while looking at your camera’s LCD display.
• If you see a faint blinking light coming from the Apple Remote in the camera’s LCD, then
the remote is working properly.
• If you don’t see any blinking light in the camera’s LCD, replace the battery in your Apple
Remote and then test it again with your computer (see “iMac G5 (iSight): How to replace the
Apple Remote battery” for instructions). (KBase article 302543)
2.
Does the IR remote now communicate with an active application that works with Apple
Remote?
Yes: IR remote is functioning correctly.
No: Replace Apple Remote.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 156
IR Sensor/Receiver
Supported applications do not respond to input from the remote control.
1.
Perform the checks above under “IR Remote” to verify that the Apple Remote is functioning
correctly, and retest. Do supported applications now respond to input from the IR remote?
Yes: Problem resolved.
No: Go to the next step.
2.
Verify that the IR Sensor can be seen in the Apple System Profiler. Open the Apple System
Profiler and click on the “USB” section. You should see the following listed:
Do you see the IR Receiver listed under the USB section of the Apple System Profiler?
Yes: Go on to the next step.
No: Replace the IR cable and retest. Refer to the “IR Board” procedure in Take Apart.
Do supported applications now respond to input from the IR remote?
Yes: Problem resolved.
No: Replace the IR sensor board and retest. Refer to the “IR Board” procedure in Take
Apart. If the issue persists after replacing these parts, replace the logic board.
3.
Access System Preferences and click Security. In the Security pane check the following:
• Make sure “Disable remote control infrared receiver” checkbox is not checked.
• If “Unpair” is available in the Security pane of System Preferences, another Apple Remote
may be paired to the computer (pairing allows only one Apple Remote to control the
computer). To delete a pairing between the remote and the iMac G5 (iSight), click Unpair.
(You may have to enter your Administrator password to make changes in the Security pane.)
After making sure these features are disabled, does the Apple Remote control the machine
now?
Yes: Problem resolved.
No: Replace the IR sensor board and retest. Refer to the “IR Board” procedure in Take Apart.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 157
Built-in iSight Camera
The built-in camera is not recognized.
1.
Boot the iMac (Early 2006) to the desktop and launch iChat AV. Note: You do not need to be
connected to a network to use iChat AV to troubleshoot. Verify that the correct versions of
Mac OS X and iChat AV are installed. Reinstall or update software as needed.
2.
Open the iChat AV preferences and click on the ‘Video’ icon. Verify whether the camera is
recognized by the iChat AV software. Is the camera recognized?
Yes: the camera is recognized and video preview is normal: This indicates the camera is
functioning. Pull down the ‘Video’ options from the menu bar and verify that the camera is
enabled. The camera must be enabled to function.
No: the camera is not recognized and no video preview is visible. This indicates the camera
may not be functioning properly. Open the iMac G5 and inspect the camera board (inside
the front bezel) and the attached cable. Reseat the cable on the camera board and check the
other end of the camera cable connection to the logic board. The camera cable connector is
on the right side of the logic board, above the AirPort/Bluetooth combo card.
3.
Replace the camera cable.
4.
Replace the camera board located inside the front bezel.
5.
If the iSight camera still doesn’t appear in System Profiler on the USB bus after replacing the
camera board, replace the logic board.
Camera recognized but no video.
1.
Verify that the lens assembly for the iSight camera located in the top middle of the front
bezel is not obstructed by anything including Post-It notes or other objects.
2.
Replace the camera board in the front bezel and retest.
Camera image quality poor.
The built-in camera is recognized by iChat AV and other supported video applications however
the image quality is poor.
1.
Verify that the lens assembly for the iSight camera is clean. Fingerprints and other
contaminants can affect image quality. Clean the lens using a lint free lens cleaning cloth
being while being careful not to scratch the lens.
2.
Verify that there is sufficient lighting to produce a good quality image. Lighting which is
comparable to that found in a well lit office will product a good quality image. If possible,
avoid having a brightly lit background. Diffused lighting is preferred over direct lighting.
3.
Launch iChat AV and open the iChat AV preferences. Click on the ‘Video’ tab. Is the video
quality acceptable?
Yes: The camera is functioning normally. The image quality problems may be caused by
bandwidth limitations when using iChat over the internet. Instruct the customer to use the
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 158
iChat AV connection doctor feature to verify that there is sufficient bandwidth to have a
video iChat session without a significant degradation of image quality.
No: The camera may not be functioning normally. Replace the camera board in the front
bezel and retest.
Camera recognized but no audio
1.
Open the System Preferences window and click on Sound.
2.
Verify that the built in iSight camera has been selected as the device for sound input.
3.
Verify that the volume settings (on the slider bar) are appropriate.
4.
Launch iChat AV and open the iChat AV preferences. Click on the ‘Video’ icon. Speak into
the microphone while monitoring the microphone level indicator. Does the line level meter
respond while you are speaking?
Yes: The microphone circuit is functioning correctly. Check the preference settings of any
supported AV applications the customer is experiencing problems with to make sure that
the microphone feature is enabled and that the internal iSight microphone has been
selected as the input device.
No: Inspect the microphone / camera cable attached to the camera board inside the front
bezel. If the cable is damaged, replace the cable and retest. If the issue continues, replace the
front bezel. The front bezel contains the microphone.
Audio Quality Poor
The camera is recognized but the built-in microphone’s audio quality is poor.
1.
Open the System Preferences window and click on Sound.
- Verify that the built-in camera has been selected as the sound input port.
- Verify that the input volume settings are appropriate. Use the volume level meter to verify
settings.
2.
Open iMovie and create a new project. Click on the Audio button and record a sound
sample. Is the sound quality acceptable?
Yes: The microphone is functioning normally. The audio quality problems may be caused by
bandwidth limitations when using iChat over the internet. Instruct the customer to use the
iChat AV connection doctor feature to verify that there is sufficient bandwidth to have an
audio iChat session without a significant degradation of audio quality.
IChat AV allows the user to limit the allocated bandwidth which could impact audio quality.
Check the settings and increase the bandwidth if needed.
No: The microphone may be faulty. Replace the front bezel which houses the microphone.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 159
Speakers
Can’t hear sound from the speakers.
1.
Disconnect any external microphones, speakers, or headphones.
2.
Access System Preferences and select Sound. In the Sound pane, select Output and make
sure the Internal speakers are selected as the device for sound output, the Output volume is
adequate, and Mute is not selected. Do you have sound now?
Yes: Problem resolved.
No: Go to the next step.
3.
Reset parameter RAM. Press Command-Option-P-R during startup but before “Welcome to
Macintosh” appears. Do you have sound now?
Yes: Problem resolved.
No: Go to the next step.
4.
Verify that the speaker cable connector is securely attached to the logic board. Do you have
sound now?
Yes: Problem resolved.
No: Replace the speakers.
5.
After replacing the speakers, do you have sound now?
Yes: Problem resolved.
No: Replace the logic board.
I hear sound out of only one speaker.
1.
Are there any external microphones, speakers or headphones plugged into the iMac?
Yes: Disconnect any external microphones, speakers, or headphones. Do you hear audio from
both of the built in speakers on your iMac?
Yes: Good. It looks like the built-in speakers are working properly. This may be an issue
with the microphone, speakers or headphones that were plugged into your iMac. Please
work with the manufacturer to troubleshoot this issue.
No: Go to step 2.
No: Check your speaker balance. If your balance setting was set to the left or right speaker,
you would only hear sound from one speaker. Go to step 2.
2.
Open System Preferences. (System Preferences can be found under the Apple menu.)
3.
Click once on the sound icon.
4.
Click once on the Output tab.
5.
Make sure your balance setting is in the middle. After adjusting the audio balance, do you
have audio from both speakers now?
Yes: It looks like the issue was the balance was not set properly.
No: Replace the speakers.
6.
If the speakers did not solve the problem, replace the logic board.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 160
Mouse
My mouse doesn’t work at all.
1.
Turn over the mouse and check the if the red LED on the underside of the mouse. Is the LED
lit?
Yes: The mouse has power. Try using the mouse on another surface. Non-reflective, opaque
surfaces without repetitive patterns work best. The surface should be clean, but not shiny.
Optical mice won’t work on glass, mirrored surfaces, glossy materials or mouse pads with
pictures.
No: There is no power to the mouse. Try plugging the mouse into one of the USB ports
on the machine. If the mouse won’t power on from any USB port, try it on a known good
machine. If the mouse fails to power on with known good machine, replace the mouse. If the
mouse will power on with a known good machine, replace the main logic board.
2.
If the underside LED is lit and the surface is good, and the mouse still does not track, try
plugging the mouse into another USB port on the machine. Does the mouse track now?
Yes: Issue resolved. Try the other USB ports on the system to make sure you don’t have a bad
port.
No: Try using a known good mouse. If a known good mouse resolves the issue, replace the
mouse. If a known good mouse does not resolve the issue, replace the main logic board.
My mouse works intermittently (the cursor freezes randomly) or is slow to
respond.
1.
Try using the mouse on another surface. Non-reflective, opaque surfaces without repetitive
patterns work best. The surface should be clean, but not shiny. Optical mice won’t work on
glass, mirrored surfaces, glossy materials or mouse pads with pictures. Does the mouse track
correctly on a proper surface?
Yes: Issue resolved.
No: Check the Mouse Tracking setting in the Mouse control panel.
2.
Boot to another volume (like the System Install Disc). Does the mouse track properly now?
Yes: Reinstall System Software
No: Try a using a known good mouse. If a known good mouse resolves the issue, replace the
mouse. If the issue persists with a known good mouse, replace the main logic board.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 161
Keyboard
Certain keys or none of the keys on the keyboard function.
1.
Unplug all devices from your computer, including your mouse and keyboard as well as
printer, scanner, external hard drives, and hubs. (Warning: Some devices may require you
to perform steps before it is safe to unplug them, e.g, external storage devices.) Be sure to
unplug your hub, if you have one.
2.
Plug your keyboard into the back of your computer firmly and securely. Plug your mouse
into the back of your computer firmly and securely. Take special care to make sure the
connector is completely in the socket. Go on to step 3.
3.
Does your keyboard work now?
Yes: Problem solved.
No: Unplug your keyboard and plug it into another USB slot on the back of your iMac. Does
it work now?
Yes: Replace the logic board.
No: Unplug your keyboard and plug your mouse into the port the keyboard just
occupied. Go on to step 4.
4.
Does your mouse work now?
Yes: Replace the keyboard.
No: Replace the logic board.
My keys are sticky or slow to respond.
1.
Try a known good keyboard.
2.
Open System Preferences. Click on the keyboard and mouse icon. Adjust the “key repeat
speed and delay until repeat” rate.
3.
Replace the keyboard.
When I type, strange characters appear on the screen.
1.
Depending on your iMac’s settings, a simple keystroke can change your keyboard from
English to Japanese. This can result in some pretty funny characters showing up when you
type. To switch to the US keyboard,
2.
Open System Preferences.
3.
Click on the International icon.
4.
Click on the Input Menu near the top of the screen.
5.
Scroll down the list and uncheck any non-US keyboard layouts.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 162
6.
Close the System Preferences. Try typing a few characters. Did is solve the problem?
Yes: Problem solved.
No: Replace the keyboard.
The USB port on my keyboard doesn’t work.
1.
Unplug all devises from your keyboard.
2.
Plug your Apple mouse into the left USB port on your keyboard. Does your mouse work
when it’s plugged into this port?
Yes: Now plug the mouse into the right port. Does it work?
Yes: Try a known good keyboard.
No: Try a known good mouse to rule out the mouse. Then go to step 3.
No: Try a different mouse or keyboard.
3.
Now unplug the keyboard from the USB port on the back of the iMac, and plug the mouse
into the port the keyboard had been in. Does the mouse work now?
Yes: Replace the keyboard?
No: It appears that your USB port isn’t functioning properly. Go on to step 4.
4.
Replace the logic board.
Error Beep(s)
Refer to Power On Self Test (POST) covered in the General Information section of this chapter.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 163
USB
A USB device doesn’t work
1.
Please unplug all of your USB devices from your iMac except your Apple Keyboard and Apple
mouse.
2.
Now plug your device directly into the back of your iMac. Does it work as expected now?
Yes: Your device works when plugged directly into the computer. This indicates a conflict
with one of the other USB devices. You can test by gradually adding your devices back
and seeing where the issue occurs, then contacting the manufacturer of the device(s)) for
assistance.
No: Unplug your device from the iMac and plug the keyboard into the port your device just
occupied. Is your keyboard still working?
Yes: Your Apple Keyboard works when plugged into the USB port your device was
plugged into. This points to an issue with your device. Please review the documentation that
came with your device. Install any necessary drivers and contact the manufacturer of your
device for assistance.
No: Replace the logic board
I see a message saying not enough power to function.
It appears that this device needs to be plugged into the computer’s USB port, rather than the
keyboard USB port. Any USB device connected to the keyboard needs to be either a self-powered
device (a USB device with its own AC power supply), or a low-power device (a device that does
not need a large amount of voltage to operate). Your device may draw more power than the
keyboard can provide.
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 164
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 165
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 166
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 167
iMac (Early 2006 20-inch) Troubleshooting — Symptom Charts 168
 Service Source
Views
iMac (Early 2006 20-inch)
© 2006 Apple Computer, Inc. All rights reserved.
iMac (Early 2006 20-inch)—Upper Exploded View
Camera Board
661-3899
Camera Board/IR Cable
922-6994
Display Panel, LCD,
Samsung
661-3895
Bracket,LCD, Left
922-7005
Cable, Display, LVDS
922-7251
Shield, EMI, Lower LCD
(not shown) 922-7137
LVDS Cable
922-7251
Speakers
922-6988
Front Bezel, 20”
922-7257
Bracket, LCD, Right
922-7004
Optical Clip
922-7156
Optical Flex Cable
922-7160
Optical Drive w/Bezel, 8x
661-3889
Optical Sensor Cable
922-6995
Optical Drive Temp Sensor
922-6995
Optical Bezel
922-6997
Optical Drive Temp Sensor
922-6995
Fan, CPU
922-
Fan, Hard Drive
922-6993
HD Bracket w/ Grommets
922-7000
Power Supply,
DC/DC, Inverter
661-3781
Cable HD, Data, Sata
922-7252
Logic Board
661-3880
AirPort Card
661-3874
J661-3874
Z661-3874
Hard Drive
661-3848 160 GB
661-3849 250 GB
661-3850 500 GB
Hard Drive Sensor Cable
922Hard Drive Temp Sensor
922-7296
Bluetooth Card
922-7289
iMac (Early 2006 20-inch) — Views 170
iMac (Early 2006 20-inch)—Lower Exploded View
AC Line Filter
922-7255
Fan, Optical Drive
922(Coming Soon)
Cover,
Stand Mechanism
922-7007
Power Supply AC/DC
661-3780
Antenna, Wireless w/Bluetooth
922-7253
Power Supply, DC/DC, Inverter
661-3878
AirPort, Antenna, Wireless
922-7241
Rear Housing
922-7259
Ambient Light Sensor
922-7250
Access Door, Memory
922-7256
SDRAM, SO-DIMM
661-3876 512 MB, 533 DDR2, 667
661-3892 1GB, DDR2, 667
IR Board
922-7295
IR Bracket
922-7297
Stand
922-7260
Apple Remote
661-3756
Stand Mechanism
922-7002
(Not Shown)
Chassis
922-7258
Not Shown:
Modem, External 661-3797
Battery 922-6476
Power Cord 922-7139
Access Tool 922-7172
Mouse 661-3896
iMac (Early 2006 20-inch) — Views 171
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