Dell Alienware M17x R3 (Early 2011) - Manual (Page 47)

Processor Module 47
2 Align the pin-1 corner of the processor module with the pin-1 corner of the
ZIF socket, then place the processor module.
NOTE: The pin-1 corner of the processor module has a triangle that aligns with the
triangle on the pin-1 corner of the ZIF socket.
When the processor module is properly seated, all four corners are aligned
at the same height. If one or more corners of the module are higher than
the others, the module is not seated properly.
CAUTION: To avoid damage to the processor module, hold the screwdriver
perpendicular to the processor module when turning the cam screw.
3 Tighten the ZIF socket by turning the cam screw clockwise to secure the
processor module to the system board.
4 Replace the processor heat-sink (see "Replacing the Processor Heat-Sink"
on page 42).
5 Replace the processor heat-sink fan (see "Replacing the Processor
Heat-Sink Fan" on page 38).
6 Replace the compartment door (see "Replacing the Compartment Door"
on page 16).
7 Replace the battery pack (see "Replacing the Battery Pack" on page 14).
CAUTION: Before turning on the computer, replace all screws and ensure that no
stray screws remain inside the computer. Failure to do so may result in damage to
the computer.