Lenovo ThinkCentre M91p User Manual page 52

This section provides instructions on how to replace the heat sink and fan assembly.
CAUTION:
The heat sink and fan assembly 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 heat sink and fan assembly, 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. Open the computer cover. See "Opening the computer cover" on page 30.
3. Disconnect the heat sink and fan assembly cable from the microprocessor fan connector on the system
board. See "Locating parts on the system board" on page 12.
4. Follow this sequence to remove the four screws that secure the heat sink and fan assembly to the
system board:
a. Partially remove screw
b. Partially remove screw
Note: Carefully remove the four screws from the system board to avoid any possible damage to the
system board. The four screws cannot be removed from the heat sink and fan assembly.
Figure 18. Screws that secure the heat sink and fan assembly
5. Lift the heat sink and fan assembly with the fan duct off the system board.
Notes:
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ThinkCentre User Guide
1
, then fully remove screw
3
, then fully remove screw
2
, and then fully remove screw
4
, and then fully remove screw
1
.
3
.