Replacing The Microprocessor - Lenovo ThinkCentre M90 Hardware Maintenance Manual

8. Position the new heat sink and fan assembly on the system board so that the four screws are aligned
with the holes on the system board.
Note: Position the new heat sink and fan assembly so that the heat sink and fan assembly cable is
toward the microprocessor fan connector on the system board.
9. Alternate tightening each screw a small and equal amount until the heat sink and fan assembly is
secured to the system board. Do not over-tighten the screws.
10. Connect the heat sink and fan assembly cable to the microprocessor fan connector on the system
board. See "Locating parts on the system board" on page 70.
11. Go to "Completing the parts replacement" on page 98.

Replacing the microprocessor

Attention
Do not open your computer or attempt any repair before reading and understanding the "Important safety
information" in the ThinkStation Safety and Warranty Guide that came with your computer. To obtain a copy
of the ThinkStation Safety and Warranty Guide, go to:
http://www.lenovo.com/support
This section provides instructions on how to replace the microprocessor.
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 microprocessor, 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 68.
3. Lay the computer on its side to get easier access to the system board.
4. Remove the heat sink and fan assembly from the system board. See "Replacing the heat sink and
fan assembly" on page 75.
5. Lift the small handle
.
Chapter 8 Replacing FRUs (Machine Types: 3029, 3054, 3139, 3219, 3246, 3282, 3349, 3421, 3544, 3652, 3769, 3934,
1 and open the retainer
4992, 5206, 5267, 5325, 5384, 5450, 5474, 5498, 5554, 5852, 6232, and 6590.)
2 to access the microprocessor 3 .
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