HP EliteDesk 800 G3 SFF Maintenance And Service Manual page 60

5. Lift the fan sink from atop the processor and set it on its side to keep from contaminating the work area
with thermal grease.
When reinstalling the fan sink, make sure that its bottom has been cleaned with an alcohol wipe and fresh
thermal grease has been applied to the top of the processor.
CAUTION:
seat the fan sink on the processor to avoid damage that could require replacing the system board.
Failure to install the baffle may cause the computer to overheat.
52 Chapter 4 Removal and replacement procedures – small form factor (SFF) chassis
Fan sink retaining screws should be tightened in diagonally opposite pairs (as in an X) to evenly