please help! psu buzzing! can't figure it out

[sancco]

hi i need some help i can't figure out why my psu is buzzing. i've had it for several years but it only just started recently. it's sounds like an electrical buzzing, and i've tried troubleshooting to no avail.

things i've troubleshooted that made no difference:
- graphics card (disconnected completely)
- sound card (disconnected completely)
- power cord
- power source (plugged it into a different wall socket)
- disconnecting all usb connections
- the power supply itself! i bought a new one because i thought mine was about to die and take everything with it, but it does exactly the same thing!

it's possible that i've only just started noticing it, but highly highly unlikely. i am often using it late at night and i would've noticed it before now, as i could even hear the cpu fan ramping up and down it was so quiet. the buzzing is much louder than the cpu fan.

thanks for anyone who can fix my problem!

 

[STACKS ON DECK]

buzzing sound can be from PSU rails or coils and maybe bad fan . . there are links on youtube about coil whinnig and buzzing so check them out and compare with the sound you are hearing from yours