Replacing The Microprocessor - Lenovo ThinkCentre Hardware Maintenance Manual

7. Lift the failing heat sink off the system board.
Notes:
a. You might have to gently twist the heat sink to free it from the microprocessor.
b. Do not touch the thermal grease while handling the heat sink.
8. Position the new heat sink on the system board so that the four screws are aligned with the
corresponding holes in the system board.
9. Follow this sequence to install the four screws to secure the heat sink, as shown in Removing the
heat sinkFigure 23 on page 82.
a. Partially tighten screw
b. Partially tighten screw
10. To reinstall the fan duct, position the fan duct on the heat sink and then press the fan duct downward
until the two tabs on the fan duct are secured into place.
11. Go to "Completing the parts replacement" on page 108.

Replacing the microprocessor

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 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. Place a soft, clean towel or cloth on the desk or surface. Hold the sides of your computer and gently lay
it down so that the screen is against the surface and the cover is facing up.
3. Remove the computer cover. See "Removing the computer cover" on page 69.
4. Remove the fan duct and the heat sink from the system board. See "Replacing the heat sink" on page 81.
5. Lift the small handle
1 , then fully tighten screw
3
, then fully tighten screw
1 and open the retainer
2 , and then fully tighten screw
4
, and then fully tighten screw
2 to access the microprocessor
1 .
3
.
3 .
.
Chapter 8 Replacing FRUs
83