Question Bought a 2nd hand PC got home and it has distorted audio both in and out. Tried everything Google suggested.

[Ali Woo]

My daughter saved up and bought pc from Facebook (I know). The guy won't refund (obviously).

We've tried everything we could google, 3 headsets, 3 speakers, it's distorted on 3.5 jack and USB, reinstalled all the drivers, reset Win 10, completely wiped it and reinstalled, the bios is up to date, tried another PSU.
It doesn't make the sound through HDMI on our TV speakers through the GFX card but does through onboard.
After a restart it varies how bad it is.
If it's really bad youtube videos look like you are holding the space bar.

Had 2 techy people say they have no idea and the local PC shop says he's never seen anything like it but suggests a new motherboard and processor.

I appreciate any help you can offer us and will answer all and any questions.
I know a bit about computers but I'm a boomer Mum so bear with me!

Intel Core i7-7700
EVGA GTX 980ti
16gb Corsair Vengeance (3000mhz)
256gb SSD
1TB HDD
Asus Z270-p
600watt EVGA

 

[JohnBonhamsGhost]

Bought a 2nd hand PC got home and it has distorted audio
youtube videos look like you are holding the space bar

likely this is why it was being sold.
never buy used systems without seeing them in use beforehand.

doesn't make the sound through HDMI on our TV speakers through the GFX card but does through onboard

if the motherboard's audio processor is damaged you could use a PCIe soundcard for 2.5mm out.

or just get a display with built-in speakers and/or their own 2.5mm output and use the graphics card as the default audio device through HDMI or DP.

Intel Core i7-7700
EVGA GTX 980ti
16gb Corsair Vengeance (3000mhz)
256gb SSD
1TB HDD
Asus Z270-p
600watt EVGA

The guy won't refund (obviously)

hopefully you didn't pay much for this old setup anyway.
really not worth much.

 

[Ali Woo]

likely this is why it was being sold.
never buy used systems without seeing them in use beforehand.

if the motherboard's audio processor is damaged you could use a PCIe soundcard for 2.5mm out.

or just get a display with built-in speakers and/or their own 2.5mm output and use the graphics card as the default audio device through HDMI or DP.

hopefully you didn't pay much for this old setup anyway.
really not worth much.

She paid £425

We were wondering whether a soundcard would work or a USB audio adapter which is cheaper but if the USB headsets didn't work maybe they wouldn't either??

 

[Ali Woo]

Just tried a Blue Yeti mic which has a sound card in it? and still crackling does this mean a PCIe soundcard wouldn't help?