NEC Express 5800/320Lc - Manual (Page 324)

System Upgrade 8-23
8. Place the CPU carefully on the socket.
TIPS: Pay attention to the orientation of the CPU.
The CPU and socket have pin marks to prevent
misinsertion.
Pin marks
9. After pressing the CPU softly against the socket, close
the levers to fasten it.
10. Remove the film of the cool sheet that is affixed on
the heat sink.
11. Place the heat sink on top of the CPU.
12. Fasten the heat sink with its clip.
Engage the clip holes with tabs on the sides of the retention: engage one hole first and
engage the other holding the first hole.