Dell OptiPlex E1 Service Manual page 65

To take advantage of future options in processor speed and functionality, you
can replace the microprocessor on your system board with any Dell-supported
microprocessor upgrade. The microprocessor is shipped with an SEPP
cartridge/heat sink assembly, which includes the microprocessor and micro-
processor heat sink.
You may also have to reseat or replace an SEPP cartridge/heat sink assembly
during normal maintenance.
SEPP cartridge
heat sink
tabs (2)
guide bracket
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Removing and Replacing Parts 4-19