Apple Xserve G5 - Manual (Page 35)

Xserve G5 Take Apart - 33 Processor
2. Using a Phillips screwdriver, remove the six screws that mount the heatsink and
processor to the logic board.
Replacement Note: There are two different types of processor mounting screws.
When installing the processor, first replace the two shorter screws in the screw holes
indicated by the squares in the illustration below. Then install the four longer screws
in the screw holes indicated by the circles.
3. Carefully lift the heatsink and processor straight up and out of the server.
Replacement Note: If you are replacing the processor in a uniprocessor configuration,
make sure you install the processor in the connector nearest the PCI fan duct. If a single
processor is installed in the other processor connector, the server will not start up properly.
Processors in a dual-processor server may be installed in either connector.