Identifying source of pc fan noise

m_stan

My pc is making a savage purring noise for around 20 seconds when I boot, like as if there is something stuck in a fan. All fans appear to be running smoothly with nothing blocking any fan blades.

It's a custom built pc and all my components are under 12months old so I want to figure out what is making the noise and have it replaced.

If I wanted to figure out which fan was making such a clatter in my pc and I disconnected every one except the cpu and psu fans, I would then next want to disconnect th cpu fan.

Only fans left running are CPU, Chipset and PSU.

But disconnecting my CPU fan, I would not want to fry my lovely P4 3.2, so how long (if at all) could I turn my pc on for without melting my silicon ?

If I stopped it booting by disconnecting my hdd, would this prevent processor meltdown ?

Any better strategies for diagnosis ?

Many thanks.

MR DAZ

M_Stan , You wont fry a p4 chip by not having the fan connected - they have a built in thermal shutdown @ around 75 degree's so it will just shut the system down.

But if you say that the noise happens in the first twenty seconds or so ...you have no need to worry.

It sounds like a a ball bearing is gone in the fan or something

stevenmu

The way I would personally do it (and I bear no responsibility if you try and something goes wrong) is to just press my finger lightly against the centre part of the fan to stop it (it only takes a tiny bit of pressure). That way you can see if it's the one making the noise, take you finger off and it'll start off again. On the off chance it doesn't spin immediatly just give it a little flick to get it started.

padraigf

Check your graphics card. Most make a godawful amount of noise until windows boots and tells them to slow the fan down.

BloodBath

System specs? I heard a lot of the x850xt's make a racket when you start up but calm down afterwards.


BloodBath

causal

I have a similar problem on my Dell Dimension 8100.
A very loud rickety racket for about 2 minutes after boot-up and then it just stops.
iirc there's no fan on the gfx card - nVidia Geforce4 MX420

Initally I whipped the case off and cleaned around the fans but it made no difference and I haven't followed up on it

causal

BigEejit

I had something similar happen on my abit IC7-G board .... it was the poxy little fan on the northbridge .... I had it replaced (the fan) under warranty....

BTW, i did clean it and put a drop of oil on the bearing but it went titsup again after a week or two

Inspector Gadget

Start with the smallest fans and work your way upwards. Many of the fan bearings have a small amount of charcoal in 'em that "sweats" lubricant, but this tends to only kick in properly after a couple of minutes. Otherwise, your noise might be expansion related - when the fan bearings warm up, they expand slightly, and the permanent magnets in the fan motors hold the fan axle more-or-less centred when its spinning.

Either way, look at some machine oil or something. WD40 or similar is more or less a waste of time.

Hope this helps,
Gadget

chorus techy

I have a similar situation - my graphics card makes a whining noise for the firs 20 or 30 minutes after boot up and continues until it warms up. I wouldn't worry too much about it tbh, most fans do make unusual sounds during boot up.

Best bet, if you want to find out what fan it is is to download a programme such as speed fan (sorry, cant remember link) and then slow each fan down one by one until the noise stops, and then look inside the case to see which fan makes noise when spinning.

tman

BigEejit wrote:

I had something similar happen on my abit IC7-G board .... it was the poxy little fan on the northbridge .... I had it replaced (the fan) under warranty....

BTW, i did clean it and put a drop of oil on the bearing but it went titsup again after a week or two

same with mine (abit nf7) the abit northbridge fans suck more ass than air tbh.
hitide.ie have a cheap passive northbridge cooler (haven't gotten round to replacing mine yet though)

jozi

Just stop the fans by pushing your finger against it as mentioned above.
Once it spins up again there isnt a problem

causal

thx for the tips & advice all

causal

m_stan

thanks all.

it's not my crappy graphics card as it has no fan - just a heatsink.

It's either my Abit ai7 chipset fan or my stock p4 3.2 fan. I will try the 'stopping it with my finger trick' tonight to figure out which it is.

thanks again

Inspector Gadget

Don't discount your power supply as a possibility if neither of those two seem to be responsible. My money's on the smallest fan - which should be the one on the northbridge.

Gadget