PSU Fan making noise after using duster

[pc-1212]

Hello everyone, I just recently bought an electronic duster and completely cleaned out my PC. I also used to spray air in the PSU where the fan is. Now, turning it on, the fan is making an extremely loud noise. I'm assuming my air blowing did this, but I'm wondering what exactly I did. I really want to get to the bottom of it, but I realize messing around with the PSU is not something you should take lightly.

 

[Petrofsky]

Unplug the computer and then turn the fan by hand with something that won't damage it, like a feather or a soda straw or a pipe cleaner, or your finger. You should be able to tell what it's hitting. If that isn't the source of the sound, blow it out again real good.

 

[pc-1212]

Hi Petro, thanks for response. I opened up the PSU (probably shouldn't have) because I originally thought a wire might have been touching it. But there are no wires near it. I also blew it out again after I had opened it up. Any other ideas?

 

[Petrofsky]

Yeah, replace the fan, if you're sure that's what the noise is.

 

[pc-1212]

I'm certain it's the fan because I've unhooked all other fans from MB. If I move the case or tap the side of the case, the loudness of the fan noise fluctuates. But it just seems odd to me that blowing it out with a duster would cause something like this. Have you seen that before?

 

[Petrofsky]

We often never know the exact mode of failure for low-value parts. It's not like the NTSB is coming in on this. I think it's a miracle those fans don't fail more often---they spin all the time and never a drop of oil do they see. Something changed. It could even be coincidence. Yank it, ditch it, put a new one in and move on to bigger and smaller things.

 

[pc-1212]

hehe, thanks for the response. I just hate when I don't know exactly what happened.

 

[Petrofsky]

OK, well, what usually happens is that the bushing goes bad, or the shaft where it goes through the bushing. The lube fails and the metal starts to wear. You can see the shaft looks a bit burnt if you take the motor apart (which I have done several times in another life). You would think that a dab of Kroil would set it to rights, but, no---only temporarily, if that. The bushing hole gets out of round, or the shaft gets rough, and that's the ball game. Noise is sometimes caused by vibration of the windings in the rotor when the lacquer quits because it's old or badly applied, or poorly formulated in a country where they think it's a good idea to put poison in baby food. A wobbly fan blade assembly can get to oscillating, slapping the rotor to the end of its travel. They are a few of the problems I've seen with small motors and fans. Hope that helps.