Buzzing from PSU

Hardware Hub PSU
1

About 20 minutes ago my PSU started a high-ish pitched buzzing which I decided to investigate while installing a new hard drive. It is a new Thermaltake Tough power gold 850W which I installed into the system I build almost a week ago (post pics soon :) ). As I took off the back panel, a strong electrostatic shock occurred between my fingers and the backplate (I hastily rebooted and everything works fine) so I unplugged the PSU from the wall. The buzzing stopped after about a second but as soon as I plugged it back in with the power supply switch in the off position, it started up again. It got a slightly higher pitch when I put it into the on position. After leaving it unplugged for about 5 minutes I plugged it in and the noise never returned. 

 

I unplugged it and am using my laptop to write this now. My question: Is the power supply safe?

 

Any help/insight would be appreciated.

 

Thanks,

Luke

EDIT: After 10 minutes of it being plugged in but the psu switch set to off, the buzzing has returned but it is very quiet

 

2

Sounds like capacitor whine. The harder you stress it the less noise it should make. That sorts the sounds.

I do not however know if it is something to worry about.

It could also worst case be a short somewhere non critical which is by it is still running. If it is it will only get worse.

3

+1 on capacitor whine. Just happens as systems get old. If it gets so bad that it hurts your ears you need to replace the PSU.

4

I had this same problem with a Seasonic 350w in my HTPC. I ran it for about a week with no issues, but then chucked it out because it was too annoying.