Core issue
The output of the show env all command can report incorrect information such as this output:
Switch#show env all
FAN is OK
Internal POWER supply is OK
RPS is NOT present
RPS is FAULTY
This problem is documented in Cisco bug ID CSCee96721.
Resolution
Upgrade to Cisco IOS Software Release 12.1(22)EA3 or later, which you can download from the LAN Switching Software page, in order to resolve this issue.