• Hardware

  • PSU buzzing even with PC shut down

Hello,

So I noticed a very faint buzzing in my PSU last night, the kind you have so stick your ear next to it to hear it, but its there and its audible, a constant low frequency buzzing. It even does it when my PC is turned off and only stops when I unplug it from the wall, it does not even stop when I flip the PSU switch off. I thought it could maybe be a capacitor dying, but maybe its just harmless coil whine.

The PSU is a CM V750 btw, it is less than 2 months old.

Anything I should be worried about or is this perfectly normal to happen for these PSUs?
Update: It stopped doing it today, I really have no idea what is causing it.
around a year ago, this happened with me on a thermaltake smart 630w, but the power supply is still working (powering a gtx 760 / i5 4670 system no prob). so i am guessing coil whine. although i did experience a lot of blue screens when i hooked it up to a gtx 970 OCed / i5 4690k OCed to 4.5 GHz, but i think that was just due to 630w not being enough for that setup.
Turn off your PC and confirm that the PSU is buzzing. Leave it alone for a few minutes and come back. If the buzzing is gone after a short time, it means it's perfectly normal. It takes time for the electrical charge to wear off. It's called coil noise.

EDIT: Just read your post again and saw that you already know what coil noise is. So don't be worried.
it might be your power outlet .. try it with a surge protector
tt400 wroteTurn off your PC and confirm that the PSU is buzzing. Leave it alone for a few minutes and come back. If the buzzing is gone after a short time, it means it's perfectly normal. It takes time for the electrical charge to wear off. It's called coil noise.

EDIT: Just read your post again and saw that you already know what coil noise is. So don't be worried.
It just stopped doing it altogether, my PC has been on for about a day and a half and I have been listening to it frequently and there are no signs of buzzing anymore, I ran some benchmark tests for about half an hour to stress my system and still no buzzing.

I'll notify if it ever does it again, maybe it has to do with the outlet itself, I'll just wait and see.