G4 Makes Horrible Noises when Put to Sleep

If I do put it to sleep it appears to sleep but then starts making this buzzing noise. It will not awake; have to punch the reset button.
Chris Pruett wrote on :

I have a G4 from ~2000 and it hates to be put to sleep. I have to disable sleep modes in Energy Saver and never hit "Sleep" on the Apple menu. If I do put it to sleep it appears to sleep but then starts making this buzzing noise. It will not awake; have to punch the reset button. As far as I can recollect its always done this.

It sort of sounds like a fan but the sound seems to emanate from the front of the computer so it could be the speaker making the racket. It's quite loud and annoying.

If I stay away from Sleep the computer is a rock. Never crashes or gives me any sort of trouble.

I forget how to properly identify it as there are several G4's. Let's see, gigabit ethernet, no shiny doors, AGP video, originally dual 500 MHz processors. It's been upgraded to dual 1000 MHz cpus.

Hardware Overview:

Machine Model: Power Mac G4 CPU Type: PowerPC G4 (2.1) Number Of CPUs: 2 CPU Speed: 1 GHz L2 Cache (per CPU): 256 KB L3 Cache (per CPU): 2 MB Memory: 1 GB Bus Speed: 100 MHz Boot ROM Version: 4.2.8f1

So anyone seen anything like this?

Thanks,

Chris