Corsair HX650 Fan going from silent to full blast then back to silent.

[toweliectl]

I have had this PSU for about 2 weeks. For the first week, no matter what I did it was nice and quiet. Now recently it will be silent, but randomly spin up to full speed, then go back to silent. Sometimes it will spin at what sounds like a medium speed. The PSU is:

 

CORSAIR HX series HX650 650W ATX12V v2.2 / EPS12V 2.91 SLI Ready 80 PLUS GOLD Certified Modular Active PFC Power Supply

 

Any thoughts?

[RAM GUY]

That is not abnormal if you are running the PSU at about 40-60% load it may be that there is not enough load to on the PSU to generate enough heat to keep the fan spinning and once it shouts off it will ramp up to full speed then come back down.