I just bought an Antec SmartPower 2.0 SP-500 500w PSU. Right now it's a placeholder for my 250w mini-PSU that's in my Soltek SFF box, so the 500w is basically hanging out on it's side. The problem I have is that upon powering up the PC, this PSU emits this HIGH-pitched tone, it reminds me of like a 15-20 kHz pure tone. It seems to be coming from the transistors/capacitors/etc from inside, not the fan. Does this sound normal at all? Maybe it seems louder becuase it's hanging out in the open? Any ideas?
Noises like that are not good. It means there's a short or a ground fault (or a missing ground).
First, make sure the PSU is grounded to the case.
If that doesn't do it, blow some canned air or similar into the PSU to see if there's a piece of dust causing a short.
After that I'd probably get on the phone to the PSU maker.
Magnetics in switching power supplies can often sqeal at the switch frequency. This would be especially noticeable during power up. It isn't harmful to the functionality. If you can isolate the noise and it turns out to be a coil or transformer you could try squirting some hotmelt on the wire coils of the sqealing component.
The PSU is completely separate from the case. I've inspected the inside already with alot of light, and see no dust. Tried dusting it, no go. I guess I'll contact Antec about this, bah, I hope I don't have to send this back in for a replacement and waste money on postage.