Lenovo ThinkCentre A85, Hardware Maintenance Manual

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CAUTION:
The heat sink and microprocessor might be very hot. Turn off the computer and wait
three to five minutes to let the computer cool before opening the computer cover.
To replace the system board, do the following:
1. Remove all media from the drives and turn off all attached devices and the computer. Then, disconnect
all power cords from electrical outlets and disconnect all cables that are connected to the computer.
2. Remove the computer cover. See “Removing the computer cover” on page 107.
3. Remove the front bezel. See “Removing and reinstalling the front bezel” on page 108.
4. Lay the computer on its side and pivot the drive bay assembly upward to gain access to the system
board. See “Accessing the system board components and drives” on page 109.
5. Disconnect the front audio and USB assembly cables from the system board. See “Locating parts
on the system board” on page 104.
6. Remove all memory modules and PCI cards that are currently installed. See “Installing or replacing a
memory module” on page 113 and “Installing or replacing a PCI card” on page 110.
7. Remove the heat sink and fan assembly from the failing system board. See “Replacing the heat sink and
fan assembly” on page 116.
8. Remove the battery from the system board. See “Replacing the battery” on page 115.
9. Carefully take note of the location of all cable connections on the system board and disconnect all the
cables. See “Locating parts on the system board” on page 104.
Chapter 9
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Installing or replacing hardware: 0104, 0154, 7539, and 7548
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