Computer is Whining at Me?

My other computer behind me is whining and refusing to start up right now. The whining has been happening for a bit, but the latter is now occurring. It'll whine as long as power goes to the computer, but it will stop once the power button is pushed or the power strip is switched to off. I'll try to list as many things as I can remember about this computer's specs:

GeForce 6800 (ASUS I believe?)
SoundBlaster Live! 24 Bit
AMD 64 3200+ Processor
ASUS Motherboard (I currently can't figure out what it is from Newegg)
Antec LifeStyle SONATA II Piano Black Computer Case
1 GB RAM
Running Windows XP

I'm sorry if this isn't enough at the moment. I have found some similar problems, but none of them match mine.

Jam it back in, in the dark.

What I mean by whine is a high pitched noise. You know, like it would come from your ears instead of a PC (which is what I thought it was at first).

The PSU is one of the things that was mentioned. I may try that first.

There's nowhere I can't reach.

Oddly, the computer works when the side panel is taken off. The whining continues, but it starts up now. Very wierd!

This thing is sticky, and I don't like it. I don't appreciate it.

It has to be the fan on the PSU. Why? I'm currently typing on the computer that has the problem. Luckily, there is software that came with one of the parts that is not detecting the fan from either the Case (a lie, because I can clearly see it running) and the PSU (which is not blowing any air out the back).

I'm currently backing up everything at the moment.

I am a dolphin, do you want me on your body?

Originally Posted by CileGray

Dont need to backup. Clean/replace PSU.

Would cleaning actually have the fan run again? I might try that. Thanks.

Edit: I replaced the PSU with another one (400 watts instead of 450) and it seems to work a lot better. Very quiet, and now there's two lights on the front surrounding the USB that glow blue.

This PSU was from another case we bought originally for this rig. Problem is, when it shuts down, it shut down a little too well (I.E. Never turned back on). We guessed that there was something wrong with the case itself, and not the PSU. Guess our theory was right.

I was speaking idiomatically.