HP Z800 - Workstation - 6 GB RAM Maintenance And Service Manual page 174

7. Set the cold plate retention ring on the CPU heatsink mounting base, and then slightly tighten a
single retention screw (see Installing the CPU heatsink on page 174).
TIP: For convenience, start with the rear CPU.
Tighten the retention ring screw only one or two turns to keep its corner in place while allowing the
rest of the ring to move.
Figure 5-109 The retention ring screws
162 Chapter 5 Replacing components ENWW