PSU randomly producing loud (fan?) noise

[Darksider13]

I’ve had the same EVGA 700B PSU for about two years now. Last night, today without any prompting or explicit causation, it started producing a loud noise. It sounds very much like the fan grinding against something, though I’m not entirely sure that’s what it is. To clarify, it is definitely not coil whine (unless coil whine can sound like a deeper whirring noise — not crackling).

I’ve loosened the screws, re-screwed and reseated the thing entirely and eventually got it sounding like it’s quiet normal self for a bit. Then whenever I moved the entire computer back to it’s original spot in my room, it starts the loud noise again.

I have two videos I’m gonna try upload in a second but in the meantime, see if ya’ll can figure anything out.

At it’s loudest.

After it had toned itself down a bit (though shortly after this, the noise ramped back up again).

How it normally sounds.

^This is when I have the case opened and sitting on the floor. Everything is fine in this form though cables connected to the computer are completely outstretched so in order to use the PC normally without tugging on wires, I have to re-place the computer in it’s usual spot on my desk. Once I move it and after a few minutes of the computer running, that’s when the sound is resurrected.

 

[InvalidError]

For what appears to be a grinding noise, either the middle of the fan's rotor is touching something or a bearing is going bad.

 

[Darksider13]

I’m leaning more toward grinding against something, though I could be wrong. When I had it on the carpet running for a solid while just now it didn’t make the noise at all. I’ve moved it back to it’s original position without the case enclosure on it and gonna let it run for a bit and see if it produces the noise at some point.

If the noise comes back, I’ll check to see if something on the bottom of the case is causing the grinding. When I reseated the PSU earlier, I cleared anything around the fan grille with an air duster, so if anything is making contact with the PSU fan it’s probably the fan mesh at the bottom of my case.

UPDATE: The noise came back a minute or two after placing the PC in it’s original spot even with the case enclosure off. Gonna try running it while on the carpet again and see if I can get the noise to reproduce. If I can’t get the noise to come back while it’s on the carpet, is that leaning more toward grinding against something or bearing going bad? If it helps in determining the issue, the sound seems to alternate in intensity right now (still in the original spot). The load on the computer won’t change but the noise sounds like every 20 sounds it gets quieter then another 10-15 seconds it slowly ramps back up again.

UPDATE 2: I took the PSU physically out of the case (didn’t disconnect cables, I just had enough slack on the power cables to pull the entire box out of the case). I shined a flashlight inside and didn’t see anything likely to be making contact with the fan. The only thing I can think of is there’s a plastic covering inside of the box just above the fan and below the port to plug a power cable into. There’s a bundle of wires that looks like it may be pressing onto the plastic covering which could potentially make contact with the fan. I inserted a soft plastic straw and very lightly pushed up on the plastic cover to see if any contact with it would leave scratches (because I didn’t see any scratches on it to indicate contact) and no mark was left. So I’m assuming if there is grinding, that would be it. Nothing else seems to be even remotely close to getting in the fan’s way. The fan isn’t dislodged or anything so it doesn’t seem like anything is visually at issue inside of the PSU. I’m starting to wonder if it’s simply a bad bearing.

UPDATE 3: I spun the fan around several times with the air duster and manually pushing it to spin. Both times it didn’t make contact or a whirring noise. The only thing I noticed is that it is able to move about a centimeter vertically. Like I could physically push the fan up with a screwdriver about a centimeter and then drop it back down that same length. Not sure if that’s normal but it doesn’t seem to effect anything either way. Totally at a loss because if there were a bad bearing, I’d hear it when I spun the fan myself. Yet nothing is colliding with the fan itself. Could be an internal part??

 

[Darksider13]

Okay so I’m at a total loss. I cleaned the damn PSU out with canned air and checked up and down to make sure nothing was making contact with the fan or anything is bumping up against something else and I don’t see a single thing. I booted my PC up and for a bit there it was totally normal. I went to take a shower, came back and the noise was back probably just as loud as the first time I experienced the issue.

I don’t think it’s a bearing and I don’t think it’s grinding against anything but I’m at a total loss for ideas. I know for sure it’s the PSU because the noise is coming from the PSU box. I just have no idea what it could be.

This is what greeted me out of the shower. I put the camera above the fan to show that the issue isn’t coming from one of the fans or the GPU. That is what it sounds like when it shuts down while making that noise.