Worrying Noise :(

[BlindMelon7]

I've been noticing a weird (almost inaudible) buzzing noise coming from my PSU after I turn off my computer. At first I thought it was the fan continuing to spin (they do that apparently) but on closer inspection it isn't turning. The noise stops if I turn it off with the switch at the back. It doesn't reappear until I actually boot up the computer.

Can anyone tell me what the noise might be?

Thanks

[Steve B]

trapped wasp?

[charleski]

Probably an inductor in the 5V stand-by circuit. If it gets louder, I'd send it back.

[BlindMelon7]

So theres not much chance of it exploding or anything? I cba to rma it (lol)

[awm]

Is it a fairly low pitched sound, similar to the hum of fluorescent lights, amps, and other power electronics. As charleski said it is probably the standby power humming with the 50/60 Hz (not sure what you have on your side of the pond) that wall current runs the always on rail.

[BlindMelon7]

I just noticed that my LCD does it too (a bit quieter though) so I'm guessing its just the dodgy wiring in my house

[awm]

No its not dodgy wiring, its just the way things work with AC power. AC (alternating current) voltage is a sine wave, which interestingly enough is the same form pressure takes in a sound wave.