Dear computer: why do you make that noise?

[Ice]

(Yes, I dust out the inside of my computer tower.)

I can't tell if my CPU fan is dying or if my power supply fan is dying. (or if it could be another problem) It starts up with a whirring noise, then after a min or two reduces to a low scratching sound that comes and goes every few seconds.

Anyone have a guess as to what is going on? Will it be expensive to fix/replace? Should I do it myself? I think I posted the same question a while back, but dusting it out took care of the problem that time. Any/all help is appreciated.

Thanks!

[Hydoso]

hard drive if its disc
um cpu heatsink fan
disc drive

um id say pop the bottom and pull the hard drive out and start it and see if it still makes that if u can take out the dvd drive just to see if its maybe trying to spin thinking it has a disc or something dumb. if its neither of those then probably ur cpu fan. not much that moves in a laptop

[Ice]

it's my desktop, not laptop.

[Khoridon Sarin]

it's my desktop, not laptop.

If you are "comfortable" poking around in there yeah go ahead and pop the side. You will need to really pay attention to get an idea of where the noise is coming from. If it's a fan, even the CPU fan it's a pretty cheap and easy fix. If it's the HD, well that's up to what kind you want but getting your head in there and listening for a bit should help narrow it down. Shouldn't be that tough in a Desktop to isolate it really. I'm no "expert" but I've built two rigs, it's not that tough to replace most of that stuff.

[Hydoso]

desktop, mk. just unplug fans one by one :P ull find which one it is.

[Bransle]

What others said; fan likely. The bearings may be wearing down.

Check to make sure there aren't any wires being hit by the fan blades; sometimes that can produce that kind of noise due to vibration as the fan powers up.

[Praetorian]

^^ this. Check for wires that may have come loose over time and are being scraped by fan blades.