Replacing The System Board - Lenovo ThinkCentre A70 7099 Hardware Maintenance Manual

Replacing the system board

This section provides instructions on how to replace the system board.
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:
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Hardware Maintenance Manual
Attention
Do not open your computer or attempt any repair before reading and understanding the
"Important safety information" in the ThinkCentre Safety and Warranty Guide that came with
your computer. To obtain a copy of the ThinkCentre Safety and Warranty Guide, go to:
http://www.lenovo.com/support
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
122.
3. Remove the front bezel. See "Removing and reinstalling the front bezel" on
page 123.
4. Lay the computer on its side for easier access to the system board. Pivot the
drive bay assembly upward to gain access to the system board. See
"Accessing the system board components and drives" on page 125.
5. Disconnect the front audio and USB assembly cables from the system board.
See "Locating parts on the system board" on page 120.
6. Remove all memory modules and PCI cards that are currently installed. See
"Installing or replacing a memory module" on page 128 and "Installing or
replacing a PCI card" on page 126.
7. Remove the heat sink and fan assembly from the failing system board. See
"Replacing the heat sink and fan assembly" on page 131.
8. 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 120.