Logic Board

Before you begin, position the computer upside down, resting the computer on an ESD mat or other soft surface and remove the following:

  • bottom housing
  • EMI cover

The logic board and the down converter board are removed together (still ^ connected to each other), and are separated once they are removed from the computer.

Dvd Rom Cable

Note: Remove SDRAM to make cable removal easier.

On the back of the CD/HD carrier, disconnect the:

  • hard drive power cable
  • hard drive data cable
  • CD-ROM/DVD-ROM data cable
  • logic board cable connector

Disconnect the antenna if it's connected to the AirPort Card, or it it's attached to the protective antenna cap.

Down Converter Imac

3. Remove the six screws on the logic board and five screws on the down converter board.

Note: The two screws located at the top of the down converter board (near the speaker) are larger screws than the other screws (with washers).

Down Converter Board

Gently lift the down converter board and logic board out of the computer.

Plastic Rivet For Computer

5. Using a flatblade screwdriver, pry the plastic rivet off the board.

Put the top half of the rivet back into the bottom half so it doesn't get lost.

6. Holding onto the down converter, press down on the black connector to separate the down converter board from the logic board.

Note: If you are returning the logic board to Apple refer to the parts database and remove the SDRAM, any cables, the modem, the AirPort Card, and I/O panel.

Replacement Note: When reinstalling the logic board, install a new thermal pad on certain models. Refer to the next page for information.

Thermal pad is used on these boards:

661-2425, 500 MHz 661-2426, 600 MHz

661-2425, 500 MHz 661-2426, 600 MHz

Thermal Pad

The thermal pad prevents the microprocessor from overheating.

It is crucial that a fresh thermal pad be used each time you detach the main logic board from the divider panel assembly. (An exception would be if you are simply testing the logic board and only detach it for a few minutes).

Continue with the procedure to install the thermal pad.

Thermal Pad

Thermal Pad

Thermal Pad Installation

  1. Pull the old thermal pad from the microprocessor.
  2. Remove the protective backing from either side of the new thermal pad and place it on the microprocessor.
  3. Press down on the pad to make sure it has even contact without air pockets.
  4. Remove the protective backing from the exposed side of the thermal pad.

Divider Panel

Thermal Pad

Divider Panel

Thermal Pad

5. Install the logic board back on to the divider panel.

Note: Avoid unnecessary contact with either side of the thermal pad as dirt or body oils reduce the thermal conductivity of the pad.

Imac Thermal Pad Size

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  • ashlyn
    How remove logic board apple 20 imac?
    9 years ago

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