Question Buzzing from PSU (? I think) when turned on but rest of PC off - - - coil whine or not ?

[JordynSQ]

Hello,

Basically as said in the title, but I will provide a little context just in case.

I build this PC ~2021, used it pretty regularly, then I got busier, so in 2022 I used it on and off. This is my first time, after a clean, using it this year. I noticed when I turned the PSU on, but not the rest of the PC (e.g., no case fans, cooler fans, or GPU fans are spinning) that there was a low buzzing that seemingly came from the PSU. Having checked my 128gb SSD (I know, planning to upgrade) the sound does not appear to be from there, and nor does it appear to be from the motherboard. I have attached a video via Imgur here, the video begins with the mic next to the PSU, then I move it up to the motherboard shield (or whatever it is called) and back down to the PSU, I believe I have isolated the sound to the PSU with this method?

Is anyone able to identify the sound? I think it might be coil whine, or am at least hoping since it appears coil whine isn't necessarily a defect, and I won't have to replace the PSU? At least that is what I've heard online, feel free to correct me if wrong.

Any help appreciated.

https://imgur.com/a/m9B1sjZ

View: https://imgur.com/a/m9B1sjZ


Specs:
MOBO: ASUS ROG STRIX H370-F Gaming
CPU: Intel i5-8500
GPU: Zotac 3060 12gb
PSU: Corsair RMx 750W
CPU Cooler: Corsair H100i Plat AIO
RAM: Corsair Vengeance 2666mhz

 

[Grobe]

This for sure sounds like typical coil whine.

This sounds usually originates from coils that are part of a voltage regulator circuit. Those are of course found in any PSU, but also at the motherboard located near the CPU.

 

[Misgar]

Can you still hear the noise when you're using the computer. Is it really annoying? Is anything else not working normally on the computer?

 

[JordynSQ]

Can you still hear the noise when you're using the computer. Is it really annoying? Is anything else not working normally on the computer?

Hello,
Sorry for the late reply. After testing, it appears the noise from the PSU goes away. It doesn't become inaudible over the fans as I tested this by holding a mic close to it. Everything seems to work fine. Admittedly, I haven't stressed the system or put it under high load. What I do get, is when shutting down, before I turn the fans and CPU etc off using the button on the PC is a similar buzzing/hum slightly loader but not from the PSU. This also appears to happen when I run MSI Afterburner if I recall correctly.