Fortron Blue Storm is buzzing in 3D apps

I just noticed that in certain situations such as when running any 3D application like ATI Tool or 3DMark my AX500-A (Fortron Blue Storm) produces a buzzing noise. I have confirmed that it IS definitely coming from the power supply (held the PSU outside of the case), so do you think it's gonna die soon or is at least malfunctioning? I'm pretty sure it has nothing to do with the fan on the PSU, it's internal.

I originally bought it on eBay around 7 months ago, would I be able to RMA it if I got the original purchase info from the seller?

Ebay, ebay, ebay..... How many of us have been countlessly screwed from there yet never learn our lessons? All for the price. There has been time where I bought off ebay for the lower price and in the end I wound up losing more then I would have spent buying it new. Temptation gets the best of us.

As for the PSU its never a good sign to hear it buzzing especially during a heavy load so yeah it is probably dying.

Any other opinions on if this thing is probably going to die? As an example, in ATI Tool, if I open up the 3D view, the buzzing instantly starts, but as soon as I close it, it stops. Open, starts, close, stops. All instantly. Running something like Prime95 doesn't seem to do anything, however.

It could be that there is a loose winding on a ferrite core. When you draw alot of current like in 3D it will buz because the windings vibrate. Prime95 wont do it because its not drawing alot of power, your video card + CPU drawing power in 3D causes it becuase there is alot more power draw. I dont think its much to worry about it can just be annoying as hell. If you can somehow pinpoint the part thats making the noise I could tell you whether or not you need to replace it. Personaly I would replace it, if its making a noise wheter its hazardous or not thats not the point, the point is its not working 100% and thus you didnt get what you paid for. I wouldent buy a PSU from ebay.

Open it up and post a few pics. Maybe the damping goo has come unstuck. It could also imply a faulty EMI filter on the primary side. Audio hum is usually due to transformer degredation. If a transformer exhibits enhanced hysterisis, it may hum as energy is dissipated via audio freq harmonics or via mechanical vibration.

You could always contact FSP and see what they have to say, They may honor the warranty.