PSU getting louder

Cleaned my PC with compressed air, found out my PSU is a EvoLabs one (budget PC so not expecting a good brand) but know its not caused by dust.

Anyway, I notice that sometimes the PSU (think its coming from there) goes abit louder and othertimes doesnt. Same load on the PC at the time, not doing anything so nothing to trigger it. Can be louder or quiet when idle so not stressing the PC. Its not massively louder. When quiet i cant hear the PC over the TV, when it goes louder i can hear it in the background

I assume its the PSU fan anyway. Only got 3 in the PC, CPU fan i can monitor and doesnt change RPM, the case fan is at the front and the noise is coming from the back. No other moving parts in the PC so has to be the PSU

What could be the cause of that the intermittent louder fan?

Fan running faster when heat rises?

Noisy bearing?

Doesnt sound like a bearing, just sounds like the fan is ramping up a few RPM. And regarding speed, thats what i thought it was a few week ago when it was boiling outside. However now its a abit cooler, temps are fine according to HW Monitor (CPU, system running mid 30c) so dont think its that.

Is a bad bearing more of a grinding noise?

Edited by bobble_bob (Thu 23-Jul-15 20:07:13)

The fan seems to make a similar noise to this, but abit quieter

https://www.youtube.com/watch?v=sHLQzA_UUjU

Could be a nylon bush on a fan spindle. Had a Dell PC than ran 24/365 for around 10 years - except for occasional reboots, upgrades and minor repairs. The PSU would start to get noisier and on taking it apart I found what had been a 1.5=2.0mm thick nylon bush/washer had worn down to paper thin. Made a replacement and it was silent for another 3 years. Or it could be components oscillating caused by a mixture of harmonics from the switch mode - can happen and is one reason you see some components with a blob of silicon sealant to stop the vibrations.

Cheers. Will keep an eye on it. Its only a mild annoyance at the moment and probably hearing it more now i know its there. Not much can do unless it gets worse other than replace psu

get & fit a replacement. it is worth the small cost to get the noise back down. I did the same a few years ago and did not regret it. Cost me about £5 all in with postage.

£5 for a PSU?!

If i did get one id pay for a decent branded one that was quieter

I'd recommend Corsair PSU.