[SOLVED] Irritating Grinding Sound on New PC

[Kirbyarm]

The specs are:
-Core i9 9900k
-MSI GTX 1080 Ti
-Gigabyte Z390 Aorus Pro Wifi
-32 GB of Corsair Vengeance LPX memory @ 3,200 MHz
-4 Be Quiet! case fans
-Noctua NH-D15 (dual fan mode)
-750W Focus SeaSonic PSU
-Fractal Meshify C case

First I tested each individual non-GPU fan in the BIOS at around 10 different speeds per fan and listened for this strange grinding noise, did not happen, so I'm assuming it's not one of those fans.

Then I did the same with MSI Afterburner for the GPU fans. Still no grinding sound.

I've tried disabling C-States in the BIOS (all of them) to see if this got rid of the grinding sound. It did nothing to help.

Primary symptom: Whenever a game is running a growling/grinding plastic sound happens for about 2-5 seconds every 8 - 10 seconds or so and it's reeeeally irritating.

When a game is not running, there is no grinding sound at all, save for quiet shorter rare bursts when loading a bunch of stuff up. Seems to happen in tandem when the PWM fans rev up momentarily.

Does anyone know what the problem could be or what potential actions need to be taken to remedy this problem?

 

[Kirbyarm]

I think it could be the PSU fan. I laid the machine on its side and pulled off the bottom dust cover and everytime I see the PSU fan spin I hear the grinding. Is there something to be done to keep it spinning slowly instead of turning it off and on automatically all the time? Or would this be a RMA thing?

 

[mdd1963]

Most PSU fans are likely somewhat automated, in that they only turn on at certain load levels or when certain temps are achieved...

(I see reading some of the Seasonic product specs, they claim it operates in 'fanless mode' up through 30% load...

Some of the current Focus Plus Gold PSUs have an extra switch (appears to be simple push-button in photo) on the rear by the on/off switch, labeled "Hybrid Mode"...; if yours is so equipped, I'd try the switch in the other position...