IBM System x3550 M4 Installation And Service Manual page 341

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.
About this task
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 that begins on "Safety" on page vii.
v Read the "Installation guidelines" on page 33.
v Read "Handling static-sensitive devices" on page 36.
To replace damaged or contaminated thermal grease on the microprocessor and
heat sink, complete the following steps:
Procedure
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.
5. Use the thermal-grease syringe to place 9 uniformly spaced dots of 0.02 ml
each on the top of the microprocessor. The outermost dots must be within
approximately 5 mm of the edge of the microprocessor; this is to ensure
uniform distribution of the grease.
Microprocessor
Figure 232. Thermal grease distribution
Note: If the grease is properly applied, approximately half of the grease will
remain in the syringe.
0.02 mL of thermal
grease
Chapter 6. Removing and replacing components
323