Fujitsu PRIMERGY TX2550 M5 Upgrade And Maintenance Manual page 146

Power supply unit (PSU)
Preliminary steps
No steps needed.
Removing the dummy cover
Figure 62: Removing the dummy cover
▶ Press in on both release latches (1) and remove the dummy cover (2).
CAUTION
▶
Keep the dummy cover for future use.
▶
If you remove a PSU and do not immediately replace it with a new
one, a dummy cover must be installed in the bay again to comply
with applicable EMC regulations and satisfy cooling requirements.
146 Upgrade and Maintenance Manual TX2550 M5