Imac Intel 21 5 Emc 2805 Logic Board Replacement Repair Guide

Difficulty

Moderate

Steps

Time Required

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Sections

Display Assembly
18 steps
Display Assembly Cables
2 steps
Display
3 steps
Lower Support Bracket
2 steps
Right Speaker
4 steps
Hard Drive Brackets
2 steps
Power Supply
10 steps
Fan
3 steps
Hard Drive Assembly
3 steps
Hard Drive Tray
2 steps
Logic Board Assembly
13 steps
SATA Data and Power Cables
2 steps
Heat Sink
2 steps
AirPort/Bluetooth Card
2 steps
Logic Board
1 step

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Introduction

What you need

Step 1

              Display Assembly

With the hinge free to move, the iMac will be unbalanced and hard to work on. Repairs are fast and easy with an iMac service wedge, but can be completed without one.
If you are using the iFixit cardboard service wedge, follow these assembly directions to put it together.
Before beginning any work on your iMac: Unplug the computer and press and hold the power button for ten seconds to discharge the power supply’s capacitors.
Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.

With the hinge free to move, the iMac will be unbalanced and hard to work on. Repairs are fast and easy with an iMac service wedge, but can be completed without one.

If you are using the iFixit cardboard service wedge, follow these assembly directions to put it together.

Before beginning any work on your iMac: Unplug the computer and press and hold the power button for ten seconds to discharge the power supply’s capacitors.

Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.

1024

Step 2

Starting on the left of the display, near the power button, insert the iMac Opening Tool into the gap between the glass panel and the rear enclosure.
The hub on the iMac Opening Tool will keep you from pushing the wheel in too far. If using a different tool, insert no more than 3/8" into the display. Otherwise, you risk severing antenna cables and causing serious damage.

Starting on the left of the display, near the power button, insert the iMac Opening Tool into the gap between the glass panel and the rear enclosure.

The hub on the iMac Opening Tool will keep you from pushing the wheel in too far. If using a different tool, insert no more than 3/8" into the display. Otherwise, you risk severing antenna cables and causing serious damage.

Step 3

Use the tool like a pizza cutter—roll it along through the gap, and it will cut the foam adhesive through the center.
Be sure to always push with the handle behind the cutting wheel. If you pull, the wheel might get pulled out of the handle.
Run the tool up along the left side of the display.

Use the tool like a pizza cutter—roll it along through the gap, and it will cut the foam adhesive through the center.

Be sure to always push with the handle behind the cutting wheel. If you pull, the wheel might get pulled out of the handle.

Run the tool up along the left side of the display.

Step 4

Continue running the tool up around the top left corner.

Continue running the tool up around the top left corner.

Step 5

Cut the adhesive along the top left of the display.

Cut the adhesive along the top left of the display.

Step 6

Continue along the top of the display.
You may want to run the tool back and forth through what you’ve already cut a few times, to ensure you get as much of the adhesive separated as possible.

Continue along the top of the display.

You may want to run the tool back and forth through what you’ve already cut a few times, to ensure you get as much of the adhesive separated as possible.

Step 7

Push the tool around the top right corner of the display.

Push the tool around the top right corner of the display.

Step 8

Wheel the tool down along the right side of the display.

Wheel the tool down along the right side of the display.

Step 9

Finish pushing the opening tool to the bottom of the right side of the display.
At this point, you’ll want to run the tool back around the entire display, to ensure you cut as much adhesive as possible.

Finish pushing the opening tool to the bottom of the right side of the display.

At this point, you’ll want to run the tool back around the entire display, to ensure you cut as much adhesive as possible.

Step 10

While the opening tool cut most of the adhesive, the display will still be slightly adhered to the case. A plastic card will be necessary to free up the last of this adhesive.
Set the iMac face-up on a table.
Starting from the top right corner of the iMac, wedge a plastic card between the display and frame.
Be careful not to insert the plastic card more than 3/8", or you may damage internal components.

While the opening tool cut most of the adhesive, the display will still be slightly adhered to the case. A plastic card will be necessary to free up the last of this adhesive.

Set the iMac face-up on a table.

Starting from the top right corner of the iMac, wedge a plastic card between the display and frame.

Be careful not to insert the plastic card more than 3/8", or you may damage internal components.

Step 11

Gently twist the plastic card sideways to create a gap between the display and frame.
Move slowly and be careful not to stress the display glass too much—you only need to make a gap of about 1/4".

Gently twist the plastic card sideways to create a gap between the display and frame.

Move slowly and be careful not to stress the display glass too much—you only need to make a gap of about 1/4".

Step 12

Slide the card toward the center of the display to cut any of the remaining adhesive along the top right corner of the iMac.
Be sure to stop before the iSight camera, or you may damage it.

Slide the card toward the center of the display to cut any of the remaining adhesive along the top right corner of the iMac.

Be sure to stop before the iSight camera, or you may damage it.

Step 13

Wedge the plastic card into the top right corner once again, and leave it there to prevent the adhesive from resticking.

Wedge the plastic card into the top right corner once again, and leave it there to prevent the adhesive from resticking.

Step 14

Insert a second plastic card into the gap between the display and frame near the top left corner of the iMac.

Insert a second plastic card into the gap between the display and frame near the top left corner of the iMac.

Step 15

Gently twist the card upward, slightly increasing the space between the display and frame.
As with the other side, twist slowly to allow the adhesive time to separate, and be careful not to over-stress the display glass.

Gently twist the card upward, slightly increasing the space between the display and frame.

As with the other side, twist slowly to allow the adhesive time to separate, and be careful not to over-stress the display glass.

Step 16

Slide the plastic card toward the center, again stopping just before the iSight camera.

Slide the plastic card toward the center, again stopping just before the iSight camera.

Step 17

Wedge the plastic card back into the top left corner.

Wedge the plastic card back into the top left corner.

Step 18

With both plastic cards inserted as shown near the corners, gently twist the cards sideways to increase the gap between display and case.
If there are any sections that seem to stick and won’t separate, stop twisting and use one of the cards to cut the remaining adhesive.
Begin to lift the top of the display up from the frame.
Only lift the display a few inches—the display data and power cables are still connected to the logic board.

With both plastic cards inserted as shown near the corners, gently twist the cards sideways to increase the gap between display and case.

If there are any sections that seem to stick and won’t separate, stop twisting and use one of the cards to cut the remaining adhesive.

Begin to lift the top of the display up from the frame.

Only lift the display a few inches—the display data and power cables are still connected to the logic board.

Step 19

              Display Assembly Cables

Use a pair of tweezers to flip up the metal retaining bracket on the display data cable.
Carefully pull the display data cable from its socket on the logic board.
Be sure to pull the display data cable connector straight out of its socket.

Use a pair of tweezers to flip up the metal retaining bracket on the display data cable.

Carefully pull the display data cable from its socket on the logic board.

Be sure to pull the display data cable connector straight out of its socket.

Step 20

While holding the display up with one hand, use the other hand to unplug the display power cable.
Lift the display up enough to have easy access to the connector, but not so much that you stretch the cables and stress their connections (about 8").

While holding the display up with one hand, use the other hand to unplug the display power cable.

Lift the display up enough to have easy access to the connector, but not so much that you stretch the cables and stress their connections (about 8").

Step 21

              Display

Lift the display up to a near-vertical position.
At this point there is still a strip of adhesive along the bottom of the display, that will hold the display to the frame like a hinge. You can loosen this adhesive by working the display up and down a few times.

Lift the display up to a near-vertical position.

At this point there is still a strip of adhesive along the bottom of the display, that will hold the display to the frame like a hinge. You can loosen this adhesive by working the display up and down a few times.

Step 22

Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply (boxed in red).
Grasp the small tab at the end of one of the bottom edge display adhesive strips and pull the adhesive toward the top of the iMac to remove it.
Repeat this step with the other adhesive strip and remove it.
If either adhesive strip breaks before it’s removed, use a plastic card to slice through the remaining adhesive.

Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply (boxed in red).

Grasp the small tab at the end of one of the bottom edge display adhesive strips and pull the adhesive toward the top of the iMac to remove it.

Repeat this step with the other adhesive strip and remove it.

If either adhesive strip breaks before it’s removed, use a plastic card to slice through the remaining adhesive.

Step 23

Lift the display up from the frame and remove it from the iMac.
It may be necessary to slowly lift from one side, to peel against the remaining adhesive.
Be very careful handling the display—it’s big, heavy, and made of glass.
If you’re replacing the display with a new one, you may need to transfer some components from the old display to the new display.
During reassembly, head over to our display adhesive guide to install the new adhesive.

Lift the display up from the frame and remove it from the iMac.

It may be necessary to slowly lift from one side, to peel against the remaining adhesive.

Be very careful handling the display—it’s big, heavy, and made of glass.

If you’re replacing the display with a new one, you may need to transfer some components from the old display to the new display.

During reassembly, head over to our display adhesive guide to install the new adhesive.

Step 24

              Lower Support Bracket

Remove the following five Phillips screws holding the lower support bracket in place:
Four 3.2 mm screws
One 1.7 mm screw
On at least some EMC 2544 machines, all five screws are the same size.
You may need to peel up the display adhesive lining the bottom edge of the iMac enclosure to access the screws.

Remove the following five Phillips screws holding the lower support bracket in place:

Four 3.2 mm screws

One 1.7 mm screw

On at least some EMC 2544 machines, all five screws are the same size.

You may need to peel up the display adhesive lining the bottom edge of the iMac enclosure to access the screws.

Step 25

Remove the lower support bracket from the iMac enclosure.

Remove the lower support bracket from the iMac enclosure.

Step 26

              Right Speaker

Use the tip of a spudger to push on either side of the right speaker cable connector to walk it out of its socket on the logic board.

Use the tip of a spudger to push on either side of the right speaker cable connector to walk it out of its socket on the logic board.

Step 27

Remove the two 10.0 mm T10 screws securing the right speaker to the rear enclosure.

Remove the two 10.0 mm T10 screws securing the right speaker to the rear enclosure.

Step 28

Insert the tip of a spudger between the right speaker and the antenna cable that is routed into the speaker’s right side.
Run the spudger down along the right side of the speaker to pry the antenna cable from its channel in the right speaker.
If the channel is not easily accessible, you can pull the speaker gently away from the case to gain access to the antenna cable.

Insert the tip of a spudger between the right speaker and the antenna cable that is routed into the speaker’s right side.

Run the spudger down along the right side of the speaker to pry the antenna cable from its channel in the right speaker.

If the channel is not easily accessible, you can pull the speaker gently away from the case to gain access to the antenna cable.

Step 29

Lift the right speaker straight up and remove it from the iMac.
It may be helpful to tip the top of the speaker away from the rear enclosure when removing it from the iMac.

Lift the right speaker straight up and remove it from the iMac.

It may be helpful to tip the top of the speaker away from the rear enclosure when removing it from the iMac.

Step 30

              Hard Drive Brackets

Remove the following screws securing the hard drive bracket to the rear enclosure:
Two 21 mm T10 Torx screws from the left-hand hard drive bracket.
One 9 mm T10 Torx screw.
One 27 mm T10 Torx screw.

Remove the following screws securing the hard drive bracket to the rear enclosure:

Two 21 mm T10 Torx screws from the left-hand hard drive bracket.

One 9 mm T10 Torx screw.

One 27 mm T10 Torx screw.

Step 31

Remove the left and right hard drive brackets from the iMac.

Remove the left and right hard drive brackets from the iMac.

Step 32

              Power Supply

The next few steps bring your hands close to the exposed face of the power supply. Do not touch the face of the power supply or any of the exposed solder. Touching it risks a high voltage shock from the many large capacitors attached to the board.
Use the tip of a spudger to push each side of the power button cable connector and gently walk it out of its socket.

The next few steps bring your hands close to the exposed face of the power supply. Do not touch the face of the power supply or any of the exposed solder. Touching it risks a high voltage shock from the many large capacitors attached to the board.

Use the tip of a spudger to push each side of the power button cable connector and gently walk it out of its socket.

Step 33

Use the tip of a spudger to push each side of the power supply control cable connector and gently walk it out of its socket.

Use the tip of a spudger to push each side of the power supply control cable connector and gently walk it out of its socket.

Step 34

Remove the two 7.2 mm T10 Torx screws securing the power supply to the rear enclosure.
In newer model iMacs these are 7.2 mm T8 Torx screws.
During reassembly, be careful not to trap the power button wire behind the board.

Remove the two 7.2 mm T10 Torx screws securing the power supply to the rear enclosure.

In newer model iMacs these are 7.2 mm T8 Torx screws.

During reassembly, be careful not to trap the power button wire behind the board.

Step 35

When working on the power supply, be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.
Tilt the power supply forward.

When working on the power supply, be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.

Tilt the power supply forward.

Step 36

Pull the power supply slightly up and out from the rear enclosure.
Rotate the power supply counterclockwise, lifting the right side up about an inch higher than the left.

Pull the power supply slightly up and out from the rear enclosure.

Rotate the power supply counterclockwise, lifting the right side up about an inch higher than the left.

Step 37

Slide the power supply to the right to clear the screw posts on the rear enclosure.

Slide the power supply to the right to clear the screw posts on the rear enclosure.

Step 38

Rock the power supply forward and remove it from its recess in the rear enclosure.
Do not try to completely remove the power supply from the iMac yet—it is still connected to the logic board.

Rock the power supply forward and remove it from its recess in the rear enclosure.

Do not try to completely remove the power supply from the iMac yet—it is still connected to the logic board.

Step 39

Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.
Flip the power supply over to access the DC power cable connection behind the logic board.
Squeeze the tab on the back side of the DC power cable connector and pull it straight out of its socket on the back of the logic board.

Flip the power supply over to access the DC power cable connection behind the logic board.

Squeeze the tab on the back side of the DC power cable connector and pull it straight out of its socket on the back of the logic board.

Step 40

You may find it helpful to set the iMac down on its back for the next couple of steps.
Use the flat end of a spudger to press the clip on the side of the AC inlet cable connector inward.
While pressing on the release clip with the spudger, grasp the AC inlet cable, and pull the connector straight out of its socket.

You may find it helpful to set the iMac down on its back for the next couple of steps.

Use the flat end of a spudger to press the clip on the side of the AC inlet cable connector inward.

While pressing on the release clip with the spudger, grasp the AC inlet cable, and pull the connector straight out of its socket.

Step 41

Remove the power supply from the iMac.

Remove the power supply from the iMac.

Step 42

Fan

Use the tip of a spudger to push the fan cable connector out of its socket on the logic board.
It is recommended to carefully push on both sides of the connector to walk it out of its socket.

Use the tip of a spudger to push the fan cable connector out of its socket on the logic board.

It is recommended to carefully push on both sides of the connector to walk it out of its socket.

Step 43

Remove the following screws securing the fan to the rear enclosure:
Two 12.5 mm T10 screws
One 9.9 mm T10 screw

Remove the following screws securing the fan to the rear enclosure:

Two 12.5 mm T10 screws

One 9.9 mm T10 screw

Step 44

Lift and remove the fan from the iMac.

Lift and remove the fan from the iMac.

Step 45

              Hard Drive Assembly

Lift the hard drive from the edge nearest the logic board and pull it slightly out of its recess.
The hard drive is attached by a single SATA power/data cable—do not attempt to fully remove it from the iMac yet.

Lift the hard drive from the edge nearest the logic board and pull it slightly out of its recess.

The hard drive is attached by a single SATA power/data cable—do not attempt to fully remove it from the iMac yet.

Step 46

Use a spudger to disconnect the single SATA power and data combo cable by gently prying its large plastic connector away from the hard drive.

Use a spudger to disconnect the single SATA power and data combo cable by gently prying its large plastic connector away from the hard drive.

Step 47

Remove the hard drive assembly from the iMac.

Remove the hard drive assembly from the iMac.

Step 48

              Hard Drive Tray

Remove the single 7.2 mm T10 screw securing the hard drive tray to the rear enclosure.

Remove the single 7.2 mm T10 screw securing the hard drive tray to the rear enclosure.

Step 49

Remove the hard drive tray from the rear enclosure.

Remove the hard drive tray from the rear enclosure.

Step 50

              Logic Board Assembly

Use the tip of a spudger to walk the left speaker cable connector out of its socket.
It is recommended to first press on one side of the connector, then press on the other side until freed.

Use the tip of a spudger to walk the left speaker cable connector out of its socket.

It is recommended to first press on one side of the connector, then press on the other side until freed.

Step 51

De-route the left speaker cable by pulling it straight up out of the retaining clip in the back of the rear enclosure.

De-route the left speaker cable by pulling it straight up out of the retaining clip in the back of the rear enclosure.

Step 52

In a similar fashion as the previous step, de-route the combo SATA data/power cable up out of the retaining clip.

In a similar fashion as the previous step, de-route the combo SATA data/power cable up out of the retaining clip.

Step 53

Use a pair of tweezers to flip up the metal retaining bracket on the iSight camera cable connector.
Pull the iSight camera cable straight out of its socket on the logic board.
This is a delicate connector that can be easily damaged.

Use a pair of tweezers to flip up the metal retaining bracket on the iSight camera cable connector.

Pull the iSight camera cable straight out of its socket on the logic board.

This is a delicate connector that can be easily damaged.

Step 54

If necessary, use the tip of a spudger to peel back the tabs covering the antenna connectors.

If necessary, use the tip of a spudger to peel back the tabs covering the antenna connectors.

Step 55

Use the tip of a spudger to disconnect each of the four antenna connectors from the AirPort/Bluetooth card.
Note the original positions for each connector when reconnecting the cables.

Use the tip of a spudger to disconnect each of the four antenna connectors from the AirPort/Bluetooth card.

Note the original positions for each connector when reconnecting the cables.

Step 56

Use the flat edge of a spudger to pry the headphone jack cable connector from its socket on the logic board.
Push the cable slightly to the right.

Use the flat edge of a spudger to pry the headphone jack cable connector from its socket on the logic board.

Push the cable slightly to the right.

Step 57

Remove the following screws securing the exhaust duct to the rear enclosure:
Two 6.3 mm T8 screws
Two 4.7 mm T8 screws

Remove the following screws securing the exhaust duct to the rear enclosure:

Two 6.3 mm T8 screws

Two 4.7 mm T8 screws

Step 58

Remove the four 7.2 mm T10 screws securing the logic board to the rear enclosure.

Remove the four 7.2 mm T10 screws securing the logic board to the rear enclosure.

Step 59

Use a pair of tweezers to peel the tape covering the exhaust duct.

Use a pair of tweezers to peel the tape covering the exhaust duct.

Step 60

Tilt the top of the logic board away from the rear enclosure.

Tilt the top of the logic board away from the rear enclosure.

Step 61

Lift the logic board straight up and out of the iMac.
Be careful not to snag the board on any of the rear case’s screw posts.
The I/O inputs at the bottom of the logic board will be the greatest challenge. It is recommended to pull gently to avoid any damage.

Lift the logic board straight up and out of the iMac.

Be careful not to snag the board on any of the rear case’s screw posts.

The I/O inputs at the bottom of the logic board will be the greatest challenge. It is recommended to pull gently to avoid any damage.

Step 62

When reinstalling the logic board, check the alignment of the exterior I/O ports. The logic board can sit crooked even when secured with all its screws.
Use a USB flash drive and/or ethernet cable to keep the logic board aligned while you screw it in.

When reinstalling the logic board, check the alignment of the exterior I/O ports. The logic board can sit crooked even when secured with all its screws.

Use a USB flash drive and/or ethernet cable to keep the logic board aligned while you screw it in.

Step 63

              SATA Data and Power Cables

The SATA data connector has a clip that must be pressed to allow removal.
While pressing on the clip with your thumb, lift and disconnect the SATA data connector from its socket on the logic board.

The SATA data connector has a clip that must be pressed to allow removal.

While pressing on the clip with your thumb, lift and disconnect the SATA data connector from its socket on the logic board.

Step 64

Grasp the hard drive power connector and gently pull it out of its socket on the logic board.

Grasp the hard drive power connector and gently pull it out of its socket on the logic board.

Step 65

              Heat Sink

The following screws secure the heat sink to the logic board:
Remove the two T8 screws from the exhaust port end of the heat sink.
Loosen, but do not remove, the four captive T8 screws securing the CPU end of the heat sink.

The following screws secure the heat sink to the logic board:

Remove the two T8 screws from the exhaust port end of the heat sink.

Loosen, but do not remove, the four captive T8 screws securing the CPU end of the heat sink.

Step 66

Slowly lift and remove the heat sink from the logic board.
When reassembling your iMac, follow our thermal paste application guide to reapply the thermal paste.

Slowly lift and remove the heat sink from the logic board.

When reassembling your iMac, follow our thermal paste application guide to reapply the thermal paste.

Step 67

              AirPort/Bluetooth Card

Remove the two 3.2 mm T5 screws securing the AirPort/Bluetooth card to the logic board.

Remove the two 3.2 mm T5 screws securing the AirPort/Bluetooth card to the logic board.

Step 68

Slightly lift the AirPort/Bluetooth card and pull it straight out its socket.
Do not use excessive force to pull the end of the AirPort/Bluetooth Card away from its socket on the logic board. Doing so may cause severe damage.
When reinstalling the card, be sure it is properly seated before reinstalling the retaining screws.

Slightly lift the AirPort/Bluetooth card and pull it straight out its socket.

Do not use excessive force to pull the end of the AirPort/Bluetooth Card away from its socket on the logic board. Doing so may cause severe damage.

When reinstalling the card, be sure it is properly seated before reinstalling the retaining screws.

Step 69

              Logic Board

During reassembly of the logic board, pay attention to the position of the I/O connectors. When the board is back in the case, insert a USB or Thunderbolt cable into one of the connectors to align it perfectly.

During reassembly of the logic board, pay attention to the position of the I/O connectors. When the board is back in the case, insert a USB or Thunderbolt cable into one of the connectors to align it perfectly.

To reassemble your device, follow these instructions in reverse and use our Adhesive Strips Guide to reattach the display glass.

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Introduction#

What you need#

Introduction

What you need