Dell Precision T5400 (Late 2007) - Manual (Page 285)

Adding and Replacing Parts 285
CAUTION: The processor package and heat-sink assembly can get hot. To avoid
burns, ensure that the package and assembly have had sufficient time to cool
before you touch them.
b
Remove the processor from the existing system board and transfer the
processor to the replacement system board. See "Processor" on
page 179 for more information.
2 Set the jumpers on the replacement system board so that they are identical
to the ones on the existing board (see "System Board Components" on
page 28.)
NOTE: Some components and connectors on the replacement system board may
be in different locations than the corresponding connectors on the existing system
board.
3 Orient the replacement board by aligning the screw holes in the board with
the corresponding holes in the computer chassis.
4 Screw in the 9 screws that attach the system board.
5 Replace the heat sink assembly and tighten the four captive screws to
secure it to the system board.
6 Replace any components and cables that you removed from the system
board.
7 Reconnect all cables to their connectors at the back of the computer.
8 Replace the computer cover (see "Replacing the Computer Cover" on
page 161).
NOTICE: To connect a network cable, first plug the cable into the network port or
device and then plug it into the computer.
9 Connect your computer and devices to electrical outlets, and turn them
on.