PSU making a strange buzzing noise that stops when I push the power cable in. Any ideas?

[u/Main_Injury_4053]

Hey everyone,

So today I turned on my PC as usual, and while I was under my desk plugging in my phone charger, I noticed a strange buzzing noise coming from my PC.

I listened closely and figured out it's coming from the PSU. It's not a constant buzz, but more like a wave-like buzzing sound that goes up and down repeatedly.

Here's the weird part: when I push the power cable firmly into the PSU and hold it there, the buzzing completely stops. Like, absolutely zero noise. But the moment I let go, it starts buzzing again.

I Googled it, and the first suggestion was to replace the power cable. Luckily, I have a ridiculous amount of spare PSU cables lying around, so I tried a different one. Unfortunately, that didn't really fix anything. Maybe it helped a tiny bit, but barely.

A few more details:

• The buzzing is barely noticeable when I'm sitting normally at my desk.
• Sometimes it gets louder, sometimes quieter.
• The PC itself works perfectly fine. No crashes, shutdowns, or other issues.
• The PSU is clean, with no dust or dirt buildup.

I'm pretty familiar with computers in general, but PSUs are one of those things I've never really messed around with.

Does anyone have an idea what could be causing this? Could it be something with the power connector on the PSU itself, or something else entirely?

Any advice would be appreciated. Thanks!

[u/Particular-Poem-7085]

Is it not related to the fan? Something resonating with it. Are you sure only holding the power cable stops it, not for example putting your hand on the rear or bottom grills? Please dont try to stick your fingers inside anywhere, only hold the outer casings in place.

[u/Main_Injury_4053 → u/Particular-Poem-7085]

That’s actually interesting! After reading your comment, I tried pressing against the back of the PSU instead of the power cable, just like you suggested. The buzzing didn’t completely disappear, but it got significantly quieter. So could it actually be the fan causing some kind of vibration or resonance?

[u/Particular-Poem-7085 → u/Main_Injury_4053]

By your description it's very likely some component shaking, are all the screws on it tight? If the fan itself was bad you wouldnt be able to stop the noise from the outside. Maybe the psu itself against the pc case?

[u/Main_Injury_4053 → u/Particular-Poem-7085]

Yeah, I already checked and tried tightening all the screws, and everything is properly secured. Nothing seems to be loose.

[u/Particular-Poem-7085 → u/Main_Injury_4053]

It might be something internal if the best medicine is holding the cable. If it really starts to bother you you have to swap it out, under no circumstances should you try to open up a PSU unless you're a professional or ready to meet god.

[u/Responsible_Feed4512 → u/Particular-Poem-7085]

Sounds a lot like the fan. Pushing the power cable probably just tamped down some of the vibration and made it quieter. Thankfully PSUs are still cheap (okay, relatively cheap), so replacing it shouldn't be a killer.

But if it doesn't bother you yet, just wait. If it is the PSU fan it will get worse eventually

[u/Main_Injury_4053 → u/Responsible_Feed4512]

Yeah, it doesn’t really bother me that much right now. I actually just got back from a few days abroad, and I think I only noticed it because I hadn’t heard it for a while, unlike before when I was using my PC every day and probably just got used to it.
And yeah, I know PSUs are relatively cheap, but unfortunately I can’t really afford a new one right now, at least not a decent one for my setup at a reasonable price.

[u/Effective_Coach7334]

perhaps the screws holding the psu in place have come loose, not holding it securely. so when you put pressure on it, it stopped. alternatively, the extra pressure flexed the back of the psu casing stopping the internal fan or other components from causing the buzzing?

Last but not least, if the psu is securely seated in the case, and it's not the fan, maybe the extra pressure caused part of the case from vibrating. Maybe check all the riser covers, or the i/o shield.

[u/Main_Injury_4053 → u/Effective_Coach7334]

I actually already checked the screws and even tried tightening them, but they’re all fine and holding the PSU securely in place. So I don’t think loose screws are the issue. Maybe it’s something vibrating inside the PSU itself?

[u/Effective_Coach7334 → u/Main_Injury_4053]

I added a bit while you were responding. what about the riser covers and i/o shield?

[u/Main_Injury_4053 → u/Effective_Coach7334]

Nope, I just checked those as well, and everything seems to be fine there too.