A funny noise...

[Kurtiskain]

Hi guys

Here are my specs:
Intel C2D e7400 @ 2.8GHZ
ASUS P5KPL-CM
2GB DDR2 800MHz
500W PSU
8600GT 256MB

The problem is, whenever I start the computer, a high pitched whining noise comes out of it, then settles down/goes away after around 10 mins of usage.

the noise seems o fluctuate, especially when I actually 'use' the machine. ie opening a folder, playing a game.

I have checked it is not the HDDs, i unplugged them all and it was the same, I also removed the 8600GT to see if it was that...the noise is still there.

It can't be the CPU, because I ran a stress test in the calculator by using the n! button, noise didn't fluctuate as it usually does.

Any insights?

Kurtis

[hot dog]

I had a VERY similar problem with a power supply not too long ago.  The noise was there more when I used the computer and it was NOT idle, like you described. It would make quiet, but very high pitch squealing noises.  From what I understand, the transformers and/or capacitors could go bad, then they squeal!    I swapped out the power supply and the problem went away.......

Try swapping out the power supply for a little while and see if you notice a difference..


edit: it's really difficult to tell it's the PSU when you put your ear up to it.  I did that and couldn't pin point the noise, despite that it was coming from the PSU

[BC_Programmer]

Noises from a PC always come from Fans or drives. a "Squealing" noise is usually failed bearings in a fan.

Hard Drives can often be louder then the PSU and Case fans put together, but it depends on the drive.

My old PCs Power supply sounds similar to a jackhammer- there is something loose causing the whole case to vibrate in unison with it too.

[Kurtiskain]

hmm ok.

I checked the voltages from the PSU, everything seems normal, but why would it only occur when starting up? it also gets 'worse' the longer it is turned off

[BC_Programmer]

Same problem with my old PC. Seems to randomly "decide" when it starts up wether it wil be noisy or not- sometimes it starts out noisy, other times silent, and it usually switches after a few minutes of being on. Very strange.

[hot dog]

I checked the voltages from the PSU, everything seems normal,

The voltages in the PSU I had a problem with are quite normal as well.  I used it to power two other computers without any problems but the noise.

[Kurtiskain]

Okay well i took the PSU out to test it and its the noise alright. is it failing capacitors? I don't really want to disconnect the fans as they both spin.

[hot dog]

is it failing capacitors?

Difficult to tell, I've never opened up a PSU that had bad components so I wouldn't know what they would look like or how to test them (it's generally recommended NOT to open PSUs because the capacitors store voltage even when powered off).  It could also just be the fan like BC was saying.  At any rate, if you have an extra PSU that you can swap in there for a little while, and the problem disappears....well, there's your confirmation!

If you're interested in dropping some oil in the fan bearing to check off that possibility  
here you go:  http://www.dansdata.com/fanmaint.htm

[Kurtiskain]

thanks 4 the replies, will have a look at oiling them