Fan on power supply of AllenStein DAW doesn\'t spin
 

I built an Allen Stein desktop machine about six months ago.

I bought the extra Power Supply he recommends for low noise.

I've been running the computer fine for months... but I've just noticed something: I never see the fan on the power supply spin.

It's always just still...

Is this a "low noise" feature? I.e. it only kicks in once the fan gets hot??

Or is this a disaster about to happen??

(Am I a moron for even asking??)

Tom.