Aluminum Backplane Stiffener - IBM pSeries 690 Service Manual

Aluminum Backplane Stiffener

Use the following procedure when populating the system with MCM processors that employ the use of
copper heatsinks, or if you will be replacing a system backplane prior to November 2003.
Removal
1. Turn off the power as described in "Powering Off and Powering On the System" on page 825.
2. Remove the fan chassis as described in"Fan Chassis" on page 895.
3. Perform a general cleaning operation, using a sash brush, (not the one included with the FRU kit) and
vacuum cleaner (see "Tools" on page 1011 for the tool part numbers), to remove any accumulated dust
and debris that has settled in the processor subsystem. Hold the vacuum hose near the brush to
remove any debris that the brush generates.
4. Remove the system clock card as described in "System Clock Card" on page 888
5. Remove the MCM modules as described in "MCM Module (Processor) and Pass Through Modules" on
page 845.
6. Remove all LE Modules from the backplane as described in "L3 Cache Modules" on page 865.
7. Using a 5.5 mm deep well socket wrench (part number 39F8452), remove the eight retaining screws
that secure the aluminum stiffener to the system backplane. See the following illustration for screw
locations.
Notes:
a. Due to the zero clearance between the aluminum stiffener and the sides of the processor drawer,
you must have the 5.5 mm deep well socket to loosen and remove the two outer-side retaining
screws.
b. (Service Tip) When removing the aluminum stiffener, remove the outer-top retaining screw last.
When installing or replacing the aluminum stiffener insert the outer-top retaining screw first.
Chapter 9. Removal and Replacement Procedures
889