Replacing The System Board - Lenovo ThinkCentre 0804 Hardware Maintenance Manual

11. Hold the new microprocessor by the edges and align the notches on it with the tabs in the
microprocessor socket, or align the small triangle on one corner of the microprocessor with the
corresponding beveled corner of the microprocessor socket.
12. Lower the new microprocessor straight down into the microprocessor socket on the system board.
13. Close the microprocessor retainer and lock it into position with the small handle to secure the new
microprocessor in the socket.
14. Reinstall the heat sink and fan assembly. See "Replacing the heat sink and fan assembly" on page 83.
15. Reinstall any parts and reconnect any cables that have been removed or disconnected.
16. To complete the replacement, go to "Completing the parts replacement" on page 96.

Replacing the system board

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
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, 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 73.
3. Remove the front bezel. See "Removing and reinstalling the front bezel" on page 74.
4. Lay the computer on its side for easier access to the system board.
5. Disconnect the front audio and USB assembly cables from the system board. See "Locating parts on
the system board" on page 71.
6. Remove all memory modules and PCI cards that are currently installed. See "Installing or replacing a
memory module" on page 78 and "Installing or replacing a PCI card" on page 76.
.
Chapter 8 Replacing FRUs (Machine Types: 0806, 0810, 0821, 0823, 0827, 0829,0832, 0835,
0842, 0844, 0846, 0848, 0851, and 4089.)
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