No sound output, only a weird noise (help please)

[jaimypreme]

Hi,

I have this problem with my computer which somehow doesn't output any sound but only this weird high pitched noise.

This wasn't the case in the beginning when I first had my PC. It only started (around that time) when I got a GPU replacement from a R9 390 to a GTX 970.

I've tried using both front and back audio ports with several devices.
I've tested this with essential components only but the issue still remains.
The only "fix" I used until now is using the USB adapter from my headset.

PC setup:
Intel i5-6600
MSI B150M Mortar
4 x 4 GB Kingston HyperX Fury DDR4
Seasonic M12II Evo Edition 620W
SSD + HDD

There is a little scratch on the isolated audio PCB on the left. I don't know if that could cause a problem like this. Photos on Imgur

The noise is continuous, as you can hear. Sound on SoundCloud

Thank you for any help in advance.

Edit:
This thread I made last year also correlates: link
But it says the sound worked with my IGD but that doesn't work anymore.
And also I have a different monitor now, an Acer KG271Abmidpx (not that really makes a difference I think)

 

[rocktalkrock]

In Windows, under "Control Panel > Sound > Playback", are Speakers set as your default playback device?