Lenovo 410554U Hardware Maintenance Manual page 95

3. Remove the heat sink and fan assembly cable from the system board. Note the cable location. See
"Locating parts on the system board " on page 79.
4. Follow this sequence to remove the heat sink from the system board:
a. Partially remove screw
b. Partially remove screw
5. Carefully lift the heat sink off of the system board.
6. Remove the plastic cover from the bottom of the new heat sink to expose the heat sink grease (this cover
protects the heat sink grease from contamination).
Notes:
a. Do not remove the plastic cover until you are ready to install the heat sink and fan assembly on the
microprocessor. Do not touch the grease on the heat sink and fan assembly. Do not put the heat
sink and fan assembly anywhere except on the microprocessor after the plastic cover has been
removed and the grease exposed.
b. Some heat sink part numbers will have orientation labels showing "Front of System." Heat Sinks that
do not have orientation labels should be oriented so the fan cable is toward the board connector
labeled "CPU Fan."
7. Place the new heat sink into position.
Important: Do not touch the thermal grease while handling the heat sink.
8. Align the four screws on the heat sink with the four mounting studs in the chassis.
9. Follow this sequence to install the screws, noting that fully tight is 5 in-lbs +/- 0.5 in-lbs:
a. Partially tighten screw
b. Partially tighten screw
1 , then fully remove screw
3 , then fully remove screw
1 , then fully tighten screw
3 , then fully tighten screw
2 , and fully remove screw
4 , and fully remove screw
2 , and fully tighten screw
4 , and fully tighten screw
.
Chapter 10 Replacing FRUs (Type 4105, 4157, 4217)
1 .
3 .
1 .
3 .
89