Help me identify weird noises

[onVacation]

TL;DR: What makes sounds like a (failing) HDD, except an HDD?


My PC makes weird noises. It's some kind of buzzing/scratching and pretty erratical. There's not really a pattern. 

Sometimes the noise occurs just for a split second in a period of 2 hours and sometimes it keeps doing the sound in small intervals of about .5s for 20s straight and multiple times within a few minutes.

Could be the HDD, right? Yep, except I don't have one. SSD only.


So, there's just one moving thing left: fans. Checked them all, because I thought maybe there are some cables close to one (case is a Sharkoon CA-M, so pretty tight), but that's not the case. 

They are all spinning freely.


The noise sounds something like this (closest sound I could find): 

 

Do you have any idea what might cause this sound?

[The Sloth]

of your fan blade getting obstructed?  

[onVacation]

Nope (should've put this in the tl;dr). 

Fans are fine (at least not obstructed, but a defective bearing wouldn't make that kind of noise).

[Quixotic.Estate]

A S.M.A.R.T. test could help you possibly diagnose if it truly is the HDD.

 

Just an idea.

[Guest]

Open up the case, and put your head in it. Where does the sound come from? And could it be coil whine of some kind?

[onVacation]

1 minute ago, Quixotic.Estate said:

A S.M.A.R.T. test could help you possibly diagnose if it truly is the HDD.

 

Yes, you're right. It could help diagnose the HDD. The only problem is: There is no HDD and I see no possible way an SSD could make such sounds.

1 minute ago, Dutch-stoner said:

Open up the case, and put your head in it. Where does the sound come from? And could it be coil whine of some kind?

My head doesn't even fit inside the empty case yet alone with components installed. I can't really tell which part makes the noise.

The frequency of the sound is much lower than any coil whine I've ever heard. It's more like a clacking noise. Difficult to describe. It also occurs in IDLE, which would be unlikely. Unfortunately any microphones I have at hand are not good enough to accurately record the sound over their own noise floor.

[Quixotic.Estate]

Oh my bad, I misread your post.

[Guest]

Maybe a bad connection somewhere with very small sparks? You could take out all parts, check the connectors (for example the PCI-e things) and reseat it all.

[Quixotic.Estate]

On second thought, it almost sounds like your power supply is grounding something out...

[onVacation]

Alright.

I know what's making the noise: The GPU fan(s). 

They make the described noise every time they spin up for about half a second. After that they run smoothly like they should.

Turn them off. Turn them on again. They make the noise again and proceed to run perfectly fine.

I've repeated this about 20 times now using Afterburner and got the same result everytime.

The fans are not obstructed or anything.


Do you have any idea WHY they make this noise?