Lenovo x3550 M4 Installation And Service Manual page 329

Figure 230. Thermal grease
a. Remove the plastic protective cover from the bottom of the heat sink.
b. Position the heat sink over the microprocessor. The heat sink is keyed to
assist with proper alignment.
Figure 231. Heat sink installation
c. Align and place the heat sink on top of the microprocessor in the retention
bracket, thermal material side down.
d. Press firmly on the heat sink.
e. Rotate the heat sink retention module release lever to the closed position
and hook it underneath the lock tab.
11. Reinstall the air baffle (see "Replacing the air baffle" on page 205).
12. Install the cover (see "Replacing the cover" on page 203).
13. Slide the server into the rack.
14. Reconnect the power cords and any cables that you removed.
15. Turn on the peripheral devices and the server.
Thermal grease:
The thermal grease must be replaced whenever the heat sink has been removed
from the top of the microprocessor and is going to be reused or when debris is
found in the grease.
Chapter 6. Removing and replacing components
311