About one week ago I bought a new custom build computer. Yesterday I started hearing this constant noise that appears the moment the computer is powered on and goes away the moment it shuts down. The noise is not loud, it's constant pitch and never changes. Since I heard it I can not un-hear it. It's definitely not the fans, I'm 100% of that and I don't have any HDDs (only SSDs) but I actually can't locate it, probably because of the echo in the case, it's just everywhere in the case, if I had to guess I'd say somewhere around CPU. Here's my dilemma. Maybe this was there from the beginning and I just didn't hear it before. Maybe it's normal. On the other hand, maybe it actually appeared yesterday and it's not normal. I don't want to look like a fool when I take the machine to the repair shop and they just have a laugh. I made a short video and uploaded it to Google Photos showing where I turn on the machine and shut it down. You'll hear the noise that's always there. In the video, it's actually a bit louder than in reality.
https://photos.app.goo.gl/iwRAw9P7Jo28Aq7N8

My computer:
Motherboard: ASUS ROG STRIX Z490-G GAMING (WI-FI)
CPU: Intel Core i9-10900K, Comet Lake-S, LGA1200 (BX8070110900K)
RAM: ADATA XPG SPECTRIX D50 RGB 32GB,DDR4-3600 CL18 (AX4U3600716G18A-DT50)
Cooler: SILVERSTONE Permafrost 240mm ARGB AIO WHITE water cooling (SST-PF240W-ARGB)
PSU: SilverStone 850W 80+Gold Full Modular (SST-ST85F-GS v 2.0)

So, is this normal (Cooler, PSU, CPU, motherboard, ...?) or not? Any ideas what could be making it?

Make sure it isn't a cable fouling a fan.

2 minutes ago, Chock said:

Make sure it isn't a cable fouling a fan.

I checked all the fans, also it's not coming from direction of any fan.

Maybe a vibration from a component or a loose screw or something? Just an idea.

I think it's coming from the motherboard or somewhere around CPU.

Coil whine?

7 minutes ago, Swe_Richard said:

Coil whine?

I'm just Googling that. I didn't know that was a thing. 

I'm listening to coil whines on Youtube but it doesn't really sound like any of the videos. Also, it's absolutely constant all the time, whatever I do, the sound is there, never changes a pitch at all. I also plugged back in my 6 years old computer and nothing of the sorts coming from there.. only fans and HDD sounds.

I'm gonna guess it's your AIO water cooling pump.

Coil whine is usually a video card thing.

13 minutes ago, w6kd said:

I'm gonna guess it's your AIO water cooling pump.

Coil whine is usually a video card thing.

Do AIO water cooling pump generally produce noise like that?

11 hours ago, Tomaz Drnovsek said:

Do AIO water cooling pump generally produce noise like that?

Frankly, I don't hear anything strange in your video.  But I'd be suspicious of a new pump making noise...the one in my general-purpose PC, a ~5-year-old Corsair H100i, is dead silent.  The fans make noise when they spin up, but I can't hear the pump at all.

If you're not sure if it's the pump, you can momentarily disconnect the power to the pump by pulling the power connector off to see if the sound stops.  Depowering it for a few seconds won't hurt anything.

16 minutes ago, w6kd said:

Frankly, I don't hear anything strange in your video.  But I'd be suspicious of a new pump making noise...the one in my general-purpose PC, a ~5-year-old Corsair H100i, is dead silent.  The fans make noise when they spin up, but I can't hear the pump at all.

If you're not sure if it's the pump, you can momentarily disconnect the power to the pump by pulling the power connecter off to see if the sound stops.  Depowering it for a few seconds won't hurt anything.

You don't? Listen to the sound just before the computer shuts down - it's always there but at this exact point it's very obvious what sound do I mean because it's the only sound at this point and it goes silent. This does not come from any of the fans although in the video it might sound like that. It's not produced by any moving part.

I'm just suspicious because it's coming from somewhere and it's always there, exactly the same sound, never stops when the machine is on and I don't hear anything like that on my old machine. 

Oh, well, I hope somebody knows what I'm talking about. 

 

Could be air in the cooling system. This will cause the pump to cavitate. Try laying the PC on it side or tilting it to see if it changes the sound.

 

Steve Aull

Ok just watch your video. Kind of hard to tell is it the fans spinning up real fast or something else. Do you have any software to monitor the AIO and the other fans throughout the case. Also look into MSI afterburner to monitor the system temps and other parameters.

 

Steve Aull

11 minutes ago, SteveAull said:

Ok just watch your video. Kind of hard to tell is it the fans spinning up real fast or something else. Do you have any software to monitor the AIO and the other fans throughout the case. Also look into MSI afterburner to monitor the system temps and other parameters.

I already said it's definitely not the fans. It might sound like that in the video but it's not. No software is available for my AIO water cooler.

Then go into your BIOS and see what it shows. Also try tilting the computer while its running to see if the sound changes.

 

Steve Aull