Lenovo 4221 Laptop User Manual


 
Figure 21. Removing the heat sink and fan assembly
7. Lift the failing heat sink and fan assembly off the system board.
Notes:
a. You might have to gently twist the heat sink and fan assembly to free it from the microprocessor.
b. Do not touch the thermal grease while handling the heat sink and fan assembly.
8. Position the new heat sink and fan assembly on the system board so that the four screws are aligned
with the corresponding holes in the system board and the heat sink and fan assembly cable can be
easily connected to the microprocessor fan connector on the system board.
9. Follow this sequence to install the four screws to secure the heat sink and fan assembly, as shown in
Removing the heat sink and fan assemblyFigure 21 on page 86.
a. Partially tighten screw 1 , then fully tighten screw 2 , and then fully tighten screw 1 .
b. Partially tighten screw 3 , then fully tighten screw 4 , and then fully tighten screw 3 .
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 71.
11. To complete the replacement, go to “Completing the FRU replacement” on page 103.
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.
86 Hardware Maintenance Manual