PSU fan was silent at first, now it's loud

[Nin]

Hi everyone,

I finished building a pc for my sister and her bf today. Pretty happy with it, especially how silent is it even while stress testing it. However, I just turned it on again a couple of hours later to check something and it's now pretty loud at idle. It's clear that the noise is coming from the PSU fan. It's completely normal-sounding noise--no rattling, clearly not coil whine, no buzzing--just a fan that's spinning way too fast. At all times, right from booting into Windows and being idle. I have no idea where to even start diagnosing this. In the time between booting down a silent pc this morning and booting up a loud pc just now, I haven't changed anything. Does anybody have ideas on what to check/diagnose/try?

The PSU is an MSI MAG A750GL PCIE5 Black

 

[nomdeplume]

New PSU = instant return or exchange.

 

[r00tcz]

You can disconnect the PSU and power it with just shorted PS_ON to GND on MB connector. That will run completely idle, so if it's not silent again, it's clearly fan issue.
I remember I had similar problem with PSU that had very steep fan curve and when I built the PC it was OK but as case and room got few degrees warmer, it really started ramping up fan speed even when PC was mostly idle (usual background Windows + open browser cpu usage). I ended up returning it because I wanted my PC to be reasonably silent and it was just too annoying.

 

[evernessince]

Hi everyone,

I finished building a pc for my sister and her bf today. Pretty happy with it, especially how silent is it even while stress testing it. However, I just turned it on again a couple of hours later to check something and it's now pretty loud at idle. It's clear that the noise is coming from the PSU fan. It's completely normal-sounding noise--no rattling, clearly not coil whine, no buzzing--just a fan that's spinning way too fast. At all times, right from booting into Windows and being idle. I have no idea where to even start diagnosing this. In the time between booting down a silent pc this morning and booting up a loud pc just now, I haven't changed anything. Does anybody have ideas on what to check/diagnose/try?

The PSU is an MSI MAG A750GL PCIE5 Black

This power supply line is known to have a loud fan: https://hwbusters.com/psus/msi-mag-a850gl-pcie5-850w-psu-review/9/

Definite loud, everyone's depiction of the concept is different. One man's 30 Db another's 40 Db. Best to use a soundmeter to measure.

Might be a good idea to test the PSU outside the case as case slot shape and obstruction can impact PSU noise. If the noise does occur outside the case you can rule out the case.

 

[cvaldes]

Don't bother measuring the noise with a sound meter app on your phone. If it bothers you do as others here have suggested and return/exchange the PSU. It's brand new, it shouldn't be behaving this way.

The number on the sound meter app is just that: a number. If the noise is audible to your ears that's what matters.

Best of luck.

 

[evernessince]

Don't bother measuring the noise with a sound meter app on your phone. If it bothers you do as others here have suggested and return/exchange the PSU. It's brand new, it shouldn't be behaving this way.

The number on the sound meter app is just that: a number. If the noise is audible to your ears that's what matters.

Best of luck.

The noise of this PSU will be very noticeable as stated by the review. You are essentially recommending the OP lie about the return reason and send back a product performing as expected and reviewed.

 

[cvaldes]

The noise of this PSU will be very noticeable as stated by the review. That's not abnormal, that's within expectations. You are essentially recommending the OP lie about the return reason.

No lying would be involved.

Most retailers in my area (USA) have a customer satisfaction policy. If you aren't satisfied you can return the item. Sometimes for a refund, often for a store credit. Since OP still needs a PSU, the store credit would be fine.

Again, downloading a sound meter app is a waste of time here. He just needs to believe "I am not satisfied with my purchase." Don't make this more complicated than necessary.

Whether or not OP's particular sample matches the sole (and thus statistically insignificant) sample from a negative review is completely irrelevant here. This is a customer satisfaction judgment, simple as that.

 

[sLowEnd]

This power supply line is known to have a loud fan: https://hwbusters.com/psus/msi-mag-a850gl-pcie5-850w-psu-review/9/

That it was silent at first is likely a fluke, this PSU does not have a fan-off mode. Download a sound meter with your phone and measure the noise levels. If they exceed those in the chart significantly, then you might have a valid issue on your hands.

Based on the review you linked, it shouldn't be loud at idle. graph says the thing should be in the 25-30db area from 0W to about 600W. Unless the OP's system is sucking down 600W at idle, something doesn't sound right about the noise situation to me. It probably is a defective unit

 

[evernessince]

Based on the review you linked, it shouldn't be loud at idle. graph says the thing should be in the 25-30db area from 0W to about 600W. Unless the OP's system is sucking down 600W at idle, something doesn't sound right about the noise situation to me. It probably is a defective unit

We don't know unless OP actually provides a sound clip or measures the volume. You have to remember one person's definition of loud is very subjective. You seem to be assuming a certain volume based on your own idea about what loud is but unless OP provides dB level, we know basically nothing about the actual volume. I've had people complain about 21 dB fans in their systems before, I can certainly see 30 dB being called "loud" depending on ambient noise levels.

No lying would be involved.

Most retailers in my area (USA) have a customer satisfaction policy. If you aren't satisfied you can return the item. Sometimes for a refund, often for a store credit. Since OP still needs a PSU, the store credit would be fine.

Again, downloading a sound meter app is a waste of time here. He just needs to believe "I am not satisfied with my purchase." Don't make this more complicated than necessary.

Whether or not OP's particular sample matches the sole (and thus statistically insignificant) sample from a negative review is completely irrelevant here. This is a customer satisfaction judgment, simple as that.

That really depends on where OP bought it. Returning a product for noise that may well be within spec falls under the "I don't like it" category of returns and places like Amazon will charge a restocking fee and deduct return shipping on that. Same applies to eBay.

Mind you, kind of crazy people jump to returning. It could very well be the case's ventilation slot shape / obstruction that's increasing the noise, as GN has demonstrated as a significant factor. OP should first try the PSU outside of the case to see if the noise persists.

People jumping to returning without doing basic testing just adds to the cost everyone pays for parts. That cost is passed on and it's silly for what may well be a perfectly working part with an extremely easy fix.

 

[cvaldes]

Amazon has never applied a restocking fee to me. And I've been shopping with them since the Nineties when they just sold books and later audio CDs.

And these days (and even before the pandemic), there's no return shipping fee. It's just a simple drop-off at the nearby UPS Store within walking distance.

You're still missing the point. If OP is unhappy with the product, a reputable (US) retailer will take it back no questions asked. It's not they're going to ask him/her for the dB/A measurement.

And it's not like consumer-grade PSUs have user adjustable controls. And if works outside the case with a minimal test load, that's not the same as using it inside a case with a typical gaming load. There's something clearly wrong with the part.

Why are you so gung ho on making this super complicated for OP? The simplest remedy is to return the PSU by invoking the customer satisfaction policy. End of discussion, no explanation or decibel measurement necessary.

 

[evernessince]

Amazon has never applied a restocking fee to me. And I've been shopping with them since the Nineties when they just sold books and later audio CDs.

And these days (and even before the pandemic), there's no return shipping fee. It's just a simple drop-off at the nearby UPS Store within walking distance.

This is a cap, because I've been assessed such a fee and been charged shipping. Amazon has been charging return shipping fees on certain items for the last 2 years.

Just because it doesn't happen to you is irrelevant, factually speaking they do and you can look that up.

You're still missing the point. If OP is unhappy with the product, a reputable (US) retailer will take it back no questions asked. It's not they're going to ask him/her for the dB/A measurement.

Why are you so gung ho on making this super complicated for OP? The simplest remedy is to return the PSU by invoking the customer satisfaction policy. End of discussion, no explanation or decibel measurement necessary.

Or it could be a very simple fix like removing the dust filter or a cable just barely dipping into the fan path, perhaps even a metal bracket.

The real question is why you are so intent on advising the OP to return without even doing basic checks. It takes less than a minute to unscrew the PSU from the case and test the system like that.

And it's not like consumer-grade PSUs have user adjustable controls. And if works outside the case with a minimal test load, that's not the same as using it inside a case with a typical gaming load. There's something clearly wrong with the part.

I mean this is just factually incorrect, a ton of PSUs have an eco mode switch that allows you to set the fan to 0 RPM under a certain load. This one doesn't but your statement is factually incorrect nontheless.

You keep saying "clearly" but no testing or data has thus far been fostered. Your level of certainty based on nothing is frightening.

 

[holyprof]

I had a similar problem. My 4 years old Corsair TX650M has been reasonably quiet until last May. Then it started producing a constant fan noise that's not unbearable, but certainly unpeasant especially when listening to calm music or editing audio/video.
I cleaned my PC case with a vacuum cleaner first, then with a compressor. Removed the PSU and gave it a compressor clean as well. The noise was still there.
So I was thinking of a GPU upgrade and that noise pulled the trigger. Replaced my noisy Aorus RTX2080Ti turbo with a whisper quiet MSI 5070Ti Gaming Trio (even in light gaming fans are at zero RPM) and the PSU with a Corsair RM850X (also with idle fan stop up to around 300W).
My PC is now so quiet I can hear my wifes's PC fans from 2 metres away.

So if you're unhappy with the PSU and can return it, I recommend to pick another one, even if a bit more expensive, but with proven low noise.

 

[Grimling]

I have a Corair 750 sfx one, the fan does not even spin under a load of 300 watts. so even under full CPU load, the fan does not spin at all. So i would recommend a psu with semi passive fan like that.

 

[Shrek]

I'm guessing it already has good flow from the case fans.

 

[_roman_]

pretty loud at idle

that implies a very cheap build quality psu.

Medium priced power supply units have a fan curve. Usually at 60% or higher load the fan slowly starts spinning.

 

[JIWIL]

This is all getting a bit complicated. It was working fine:

Pretty happy with it, especially how silent is it even while stress testing it.

Then it wasn't:

I just turned it on again a couple of hours later to check something and it's now pretty loud at idle

Return it. Or test in another system if you feel it's worth your time.