The 3300 series fan's power supply will stop working if either of the following conditions occurs:
1. The internal 25 Amp circuit breaker is triggered
2. The internal relay comes loose
If either situation occurs,
disconnect the supply power cord from the wall outlet.
To reset the power supply's circuit breaker
The circuit breaker can be located without removing the cover of the power supply. Look through the holes on the right side of the power supply. The white button is located at the top left of the right side panel. Check whether it is popped open (upward). It can be reset without removing the case by using a paper clip.