Article ID: 16079 
Products
WS-C5210, supported with firmware 8.21.01.0198 and higher
Changes
Model WS-C5210 IdentiFi Wireless Controller deployed into the network.
Symptoms
System LED is amber.
Fan speed increases to high - sounding loud or noisy.
Fans run at maximum speed until either the controller is rebooted or the power supply is disabled.
Presence of log messages similar to the following, referencing 
 or 
:
            code:Power Supply sensor PS2 Status - Predictive failure Asserted
 
Cause
The internal BIOS settings issue incorrect hardware commands when a perceived environmental change - such as a detected, possibly transient, power failure - is introduced.
Solution/Workaround
Please 
contact the GTAC for assistance.
Workaround:
Reboot the controller whenever this condition occurs - after hours, days, or weeks of runtime.