Lenovo 4004 Personal Computer User Manual


 
4. Pull the intrusion switch to remove it from the heat sink bracket.
Figure 44. Removing the intrusion switch
5. Follow this sequence to remove the four screws that secure the heat sink and fan assembly to the
system board:
a. Partially remove screw 1 , then fully remove screw 2 , and then fully remove screw 1 .
b. Partially remove screw 3 , then fully remove screw 4 , and then fully remove screw 3 .
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 45. Removing the heat sink
6. Lift the failing heat sink off the system board.
Notes:
56 ThinkCentre User Guide