Lenovo ThinkCentre M79, Hardware Maintenance Manual

Page: 143 / 186

Replacing the system board
Attention: Do not open your computer or attempt any repair before reading and understanding the Chapter
1 “Read this first: Important safety information” on page 1.
Note: Each computer has a unique Vital Product Data (VPD) code stored in the nonvolatile memory on the
system board. After you replace the system board, the VPD must be updated. To update the VPD, see
“Updating or recovering the BIOS” on page 68.
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 removing 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 105.
3. Remove the front bezel. See “Removing and reinstalling the front bezel” on page 106.
4. Pivot the drive bay assembly upward. See “Accessing the system board components and drives” on
page 108.
5. Remove all memory modules and PCI Express cards that are currently installed. See “Installing or
replacing a memory module” on page 109 and “Installing or replacing a PCI card” on page 111.
6. Remove the heat sink and fan assembly from the failing system board. See “Replacing the heat sink and
fan assembly” on page 126.
Note: Do not let the thermal grease on the bottom of the heat sink and fan assembly get in contact
with anything.
7. Record the cable routing and cable connections and then disconnect all cables from the system board.
8. Remove the eight screws that secure the system board.
Chapter 11
.
Installing or replacing hardware
135