Retainer bracket
Heat sink
release lever
Lock tab
Microprocessor
Heat sink
12. If you installed the second microprocessor, install the fourth fan (see “Installing
a dual-motor hot-swap fan” on page 124).
If you have other devices to install or remove, do so now. Otherwise, go to
“Completing the installation” on page 135.
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.
When you are installing the heat sink on the same microprocessor that it was
removed from, make sure that the following requirements are met:
v The thermal grease on the heat sink and microprocessor is not contaminated.
v Additional thermal grease is not added to the existing thermal grease on the heat
sink and microprocessor.
Notes:
v Read the safety information on page vii.
v Read the “Installation guidelines” on page 40.
v Read “Handling static-sensitive devices” on page 42.
To replace damaged or contaminated thermal grease on the microprocessor and
heat exchanger, complete the following steps:
1. Place the heat sink on a clean work surface.
2. Remove the cleaning pad from its package and unfold it completely.
3. Use the cleaning pad to wipe the thermal grease from the bottom of the heat
sink.
Note: Make sure that all of the thermal grease is removed.
4. Use a clean area of the cleaning pad to wipe the thermal grease from the
microprocessor; then, dispose of the cleaning pad after all of the thermal grease
is removed.
106 System x3650 M4 Type 7915: Installation and User’s Guide