Buzzing PSU when plugged in, something to worry about?

[emothxughts]

I woke up this morning to a faint constant buzzing sound from my PC (specs in signature), which upon close inspection came from the PSU, the Cooler Master MWE Bronze V2 650W (230v only version). My PC was off (hibernated) but the PSU is switched on when it buzzed, I can tell because the mobo's RGB lights are on, I set it on purpose. It even buzzes for a while after I switch off the PSU. The buzz only goes away when I remove the cable from the PSU. It also went away after I enabled a certain ERP thingy in my BIOS, which also turns off the aforementioned RGB lights after I turn off my PC.

 

Should I be concerned about the PSU? Is it just a "normal" coil whine that I keep hearing about? I distinctly remember that the PSU tierlist site mentions that this PSU suffers from coil whine in low loads, but that was removed in the latest update. Or did I remember it wrong?

[Jon-Slow]

This doesn't sound like coilwhine. It sounds like your PSU's fan is faulty.

 

41 minutes ago, emothxughts said:

It also went away after I enabled a certain ERP thingy in my BIOS,

 I don't know about this, it might just be a coincident. But you can inspect the PSU more closely to see if it's the main fan. Since you've said it goes on after your turn it off, it could still be the fan trying to cool the PSU for a couple of seconds after shuting down. Might need to send it for warranty in that case.

[emothxughts]

This is not my video, but the buzzing sounds exactly like this:

 

[RageTester]

I had trouble with power supply fan getting loud on one work PC. Problem is regular shops only sell power supplies as a unit, not spare fans.

You could try blowing the dust away, add oil to fan hub if you know how, but if PSU is old, best idea is getting a new one.

[emothxughts]

7 minutes ago, Jon-Slow said:

This doesn't sound like coilwhine. It sounds like your PSU's fan is faulty.

 

 I don't know about this, it might just be a coincident. But you can inspect the PSU more closely to see if it's the main fan. Since you've said it goes on after your turn it off, it could still be the fan trying to cool the PSU for a couple of seconds after shuting down. Might need to send it for warranty in that case.

The PC is already off for 6 hours by the time I woke up. Most probably not the fan?

[Jon-Slow]

4 minutes ago, emothxughts said:

The PC is already off for 6 hours by the time I woke up. Most probably not the fan?

you mean you woke up to an "off" PC that's been off for 6 hours and it was making that noise? Do you mean it was shutdown or was in sleep mode? Regardless, you should try to see if the fan is turning when the noise is being made. I'm still putting it on the fan.

 

BUT, all of that aside. There is nothing you can do since opening a PSU is a big no no. You just have to send it back for warranty and they will probably just replace it for you without questions. Although you might need to buy a new PSU in the meantime to keep your PC running.

[RageTester]

11 minutes ago, emothxughts said:

This is not my video, but the buzzing sounds exactly like this:

 

That is not the noise level I was getting, all other sounds in video are louder compared to it.

If it turns back on I don't see much of a problem, just close the case and put computer further away from your ears.

 

[emothxughts]

41 minutes ago, Jon-Slow said:

you mean you woke up to an "off" PC that's been off for 6 hours and it was making that noise? Do you mean it was shutdown or was in sleep mode? Regardless, you should try to see if the fan is turning when the noise is being made. I'm still putting it on the fan.

 

BUT, all of that aside. There is nothing you can do since opening a PSU is a big no no. You just have to send it back for warranty and they will probably just replace it for you without questions. Although you might need to buy a new PSU in the meantime to keep your PC running.

I put it to hibernation (so turned the PC off, but not the PSU switch at the back too) 6 hours earlier, before going to bed. Woke up and heard the faint buzz from my desk.

[emothxughts]

38 minutes ago, RageTester said:

That is not the noise level I was getting, all other sounds in video are louder compared to it.

If it turns back on I don't see much of a problem, just close the case and put computer further away from your ears.

 

That's what I expected from opening this thread, I don't mind this buzz if it was just a natural physics phenomenon, but it will bother me if it turns out to be portending the doom of my PSU. But need some third or fourth opinion still, just a normal annoyance or a bad omen?

[Jon-Slow]

20 minutes ago, emothxughts said:

That's what I expected from opening this thread, I don't mind this buzz if it was just a natural physics phenomenon, but it will bother me if it turns out to be portending the doom of my PSU. But need some third or fourth opinion still, just a normal annoyance or a bad omen?

Common wisdom is that if your PSU is making a noise, you should not ignore it. It's best to get it resolved and since you're not supposed to open a PSU, that means sending it for warranty. Otherwise it's your choice if you'd want to ignore the noise.

[--SID--]

It's coilwine on the 5vSB.

MWE Bronze 230v is a very low quality PSU. Maybe look for a better unit.

[emothxughts]

8 minutes ago, --SID-- said:

It's coilwine on the 5vSB.

MWE Bronze 230v is a very low quality PSU. Maybe look for a better unit.

If the case here is that it's a mere "normal" coil whine, then I can rest a bit easy, nothing that in-game sounds or even the various fans in the PC can't drown out. I'd be really bothered though if it's a sign of imminent (catastrophic) PSU failure.

 

Speaking of which, there is the full-range version of the same PSU on the tierlist, and it's listed as tier B there as opposed to mine that is in tier C. I wonder why? (If it's relevant, I live in a country with 230V mains only)

 

 

[emothxughts]

Update: Got back from work, no buzzing sound on the PSU (I enabled ERP in BIOS in the morning before work). It turns on, I ran some power-intensive apps, no buzz/whine either. Hope I don't jinx this...

[emothxughts]

Update again: Jinxed it. This morning it whined again, hours after I hibernated the PC. Some additional observations:

• It continues buzzing for a few seconds after flipping off the switch. It goes away entirely if I then press the front power button.
• The buzz/hum/whine also disappears on significant loads, like running the Superposition benchmark.
• I have now also recorded the sound:20240315_062643.aac

[RageTester]

9 hours ago, emothxughts said:

Update again: Jinxed it. This morning it whined again, hours after I hibernated the PC. Some additional observations:

• It continues buzzing for a few seconds after flipping off the switch. It goes away entirely if I then press the front power button.
• The buzz/hum/whine also disappears on significant loads, like running the Superposition benchmark.
• I have now also recorded the sound:20240315_062643.aac

Hibernation still uses some power, but PSU fan probably stays idle at the time. I suggest turning PC off completely, giving all parts a proper rest.

Again that doesn't sound like a terrible catastrophic noise.

[emothxughts]

Some more findings:

 

• The PSU buzzed/whined again this morning upon me waking up, the PC is hibernated and the PSU is still on. 12 hours later, after I came back from work, it no longer buzzes.
• It buzzes every morning and it no longer buzzes every evening. I'm beginning to suspect my house's mains power is causing this.
• No crashes or sudden shutdowns ever.