NEC Express5800/320Fd-LR User Manual page 481

9.
Lift the CPU socket holder.
10.
Place the CPU on the socket carefully.
TIPS:
Pay attention to the orientation of the CPU. The CPU
and socket have pin marks to prevent misinsertion.
Check the pin marks of the CPU and the socket and
insert the CPU correctly.
11.
After pressing the CPU softly against the socket, place the
CPI socket holder back to its original place.
12.
Return the socket lever back to its original place.
13.
Place the heat sink on the CPU and secure it with 4 screws.
Loosely fasten the screws in the cross-coupling way, and then
fasten them tightly.
System Upgrade 8-27