Computer making a "whining" electrical noise

[LocustHorde]

I always leave my computer on, but I had to turn it off briefly. When I turned it back on, it had trouble starting up, but eventually it started back up, but now there's a faint intermittant electrical whining noise. The sound is not too loud, but quite annoying.

My guess is the power supply is on its last leg??

[Bremen]

It could be a number of things. Capacitors whine, although I don't think this changes (?) so its not something that would just start out of the blue. Could also be a fan where something got into it causing excess friction. It could be the power supply. Maybe the hdd going. If you're brave open up the case and try to identify where the whine is coming from.

[LocustHorde]

being that I put the thing together about a year ago, it shouldn't pose much of a problem opening it up lol.. I just never seen something (or should I say heard?) like this before.. It does sound like it's coming from the PS

[Josem]

1) figure out where noise is coming from
2) replace part
3) ?????
4) profit

[imsobroke]

Do you have onboard speakers? I had this problem with some POS units at work. I disconnected the onboard speakers and the annoying noise went away.