IBM 7378, Problem Determination And Service Manual

Page: 309 / 362

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.
To replace damaged or contaminated thermal grease on the microprocessor and
heat sink, 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.
Microprocessor
0.02 mL of thermal
grease
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. This is to ensure uniform distribution.
Note: 0.01 mL is one tick mark on the syringe. If the grease is properly applied,
approximately half (0.22 mL) of the grease will remain in the syringe.
6. Install the heat sink onto the microprocessor as described in “Installing a
microprocessor and heat sink” on page 286.
Chapter 5. Removing and replacing server components
291