How to determine which fan is noisy

[lunbux]

All of a sudden, my machine started making a noise and I couldn't pinpoint which fan is making it. Here's my current setup: http://i.imgur.com/PmVmmox.jpg

At the center is obviously the processor with the stock fan, and that red board below is my video card. By the way, my CPU is like 2 inches above the ground, which makes it quite hard to put my ear close to listen to it.

Now, I'm trying to figure out a sure-fire way to determine which of the two is causing the noise. I already cleaned up the dust and made sure that they're both attached properly. I read before that some people push the center of the CPU fan to stop it from spinning but I find that scary, aside from it being impossible. As you can see from the pic, the center of the fan is blocked. And I wouldn't dare physically stopping it from the blades. They look flimsy and I'm afraid of damaging them.

Oh, and I would just like to point out that both my CPU and GPU have normal temperature. CPU fan is spinning at 1031 RPM at idle, while I don't know about the GPU because http://i.imgur.com/uWANCoU.jpg I've also tried SIW and TechPowerUp GPU-Z and they're both giving me 0.

In other words, there seems to be no way to find out how much it is spinning. It's definitely spinning though, since I can play games and watch vids and it doesn't overheat.

I already have plans of upgrading my GPU even before this started, but I'm curious as to the SAFE ways of diagnosing this issue.

 

[cklaubur]

If your computer is in a case, have you eliminated that as a possibility? At least with a case fan, you can unplug it (with the system off, of course!) and identify if that's the culprit.

Also, if your computer is in a case, try placing it on its side, so the CPU fan is horizontal and the GPU is vertical. That should change the bearing loads in the fan motors, and the noise should change or go away. Afterwards, try removing the GPU completely to eliminate it as the source of the noise.

Casey

 

[USAFRet]

An empty paper towel tube, or rolled up piece of paper. Held up to your ear.
Aim it at each fan, see if anything sounds 'off'.

 

[lunbux]

If your computer is in a case, have you eliminated that as a possibility? At least with a case fan, you can unplug it (with the system off, of course!) and identify if that's the culprit.

Also, if your computer is in a case, try placing it on its side, so the CPU fan is horizontal and the GPU is vertical. That should change the bearing loads in the fan motors, and the noise should change or go away. Afterwards, try removing the GPU completely to eliminate it as the source of the noise.

Casey

Like I said, the only suspects are the CPU and GPU fans. I'm thinking of unplugging the CPU fan but I'm not sure if it's safe. There was one time when I carelessly left a cable in the way preventing the fan from spinning. Good thing I immediately saw my CPU temp skyrocket to above 90C and shut my PC down.

Putting my computer on its side is a bit impossible because the plug (to the AVR) would come off. I know it sounds ridiculous, but understand that I work in a REALLY restricted space.




As for the tube method, I tried it and it does SEEM that the noise is coming from the GPU, which is a good thing considering the fact that I'll be replacing it soon, but I find this method not that definitive. At least, not as definitive if I were to have a safe method of stopping either fan from spinning. Nonetheless, I'll try it again during boot up since that is when the noise is the loudest.

 

[cklaubur]

Ok, I think I understand how your computer is set up. It's set up like a test bench, correct?

USAFRet's tube idea would definitely be an easier test. However, you still have the option of removing the video card to identify one way or the other which fan is the noisy one. Booting without the video card installed won't hurt the computer one bit.

Casey

 

[lunbux]

Ok, I think I understand how your computer is set up. It's set up like a test bench, correct?

USAFRet's tube idea would definitely be an easier test. However, you still have the option of removing the video card to identify one way or the other which fan is the noisy one. Booting without the video card installed won't hurt the computer one bit.

Casey

Hmm, I don't think mine looks like a test bench. My image of a test bench is that the computer is on top of a table or desk, high enough for you to see the insides while sitting.
Anyway, if it's safe to totally remove the video card and boot up, then I'll do that and see what happens.

Thanks.

 

[lunbux]

PS

I just tried it and it's definitely my GPU fan making the horrible noise. LOL
It's really a good thing I'm already set up on upgrading, though I might have to rush things up a bit now. Again, thanks for the tips, Casey and USAFRet.