Lenovo ThinkCentre A70 7099 Hardware Maintenance Manual page 107

7. Remove the four screws 1 that secure the heat sink and fan assembly to the
system board.
Note: Carefully remove the four screws from the system board to avoid any
possible damage. The four screws are integrated parts of the heat sink and fan
assembly and they cannot be removed from the heat sink and fan assembly.
Figure 19. Screws that secure the heat sink and fan assembly
8. Lift the 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. When handling the heat sink and fan assembly, do not touch the thermal
grease on the bottom of it.
9. Place 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.
Make sure that you properly place the new heat sink and fan assembly so that
you can easily connect the new heat sink and fan assembly cable to the
microprocessor fan connector on the system board.
10. Alternate tightening each screw a small and equal amount until the new heat
sink and fan assembly is secured to the system board. Do not over-tighten the
screws.
11. Connect the new heat sink and fan assembly cable to the microprocessor fan
connector on the system board. See "Locating parts on the system board" on
page 86.
12. Reconnect any cables that have been removed.
13. To complete the replacement, go to "Completing the parts replacement" on
page 114.
Chapter 8. Replacing FRUs - Tower computers
101