Loud Whirring Noise When Booting

[Init 4 Beans]

90% of the time, after i have left my PC turned off for a few hours and then boot the computer, a loud whirring noise comes from the fan of the PSU.

Im not sure of the cause, but i have an inklink that it might be because it starts spinning the wrong way, because when i blow on it, it stops whirring and just fans normally.

Although, it does look abit dusty, would that be the cause? Im gonna invest in some compressed air anyway and give it a good squirt.

I just posted this to think if anyone else could think of an idea why it might be whirring so loudly?

Thanks.

 

[Guigsy]

The bearings of the fan are on the way out. They start noisy, but often go quiet once they are up to speed, particularly on a PSU if they are heat controlled. It will worse with time. The problem is that one day it'll be totally silent because it's stopped spinning. Either get a new fan or change the PSU, you don't want an overheated power supply.

 

[markyb]

^^ Very true.

To check which fan it is, hold your tumb gentley on the motor of the fan, the inside bit so that the fan slows down.