Question Problem with new GPU

[Nivz0r]

Hey,
3 days ago i bought Asus rx 560 4gb for a custom build.
In the mean time i plugged it to my PC to make sure everything is good only to find out it's not.

The GPU is only for show and to display 4k60hz on a 65 qled tv.
Thing is after i plugged the gpu the pc started crashing from Youtube.
The CPU goes to like 70% usage when im watching a video. And everything is stuck also The sound is crashing which is my main concern.

My pc specs:
I9 9900
Asus tuf z390 plus gaming
Corsair 2x8 3600mhz
Ssd samsung evo plus 500gb
Hdd 2tb
750w psu

The pc worked great before the gpu.
The PC is 3months old.
I don't know if to return the gpu and buy something else.
I updated all pc drivers including the gpu, also tried older drivers for gpu. No luck whatsoever.

 

[SteveRX4]

Try another GPU - or buy one (560s should be cheap).
Try the 560 in another PC.

 

[Nivz0r]

Try another GPU - or buy one (560s should be cheap).
Try the 560 in another PC.

So this is definitely something in my PC.
I tried the GPU in a different PC and it works great.
Also tried different GPU in my PC and it won't even show picture.
Now my PC won't show picture with any of the GPUs or even connected to the motherboard.

My PC is connected to Samsung 4k 55" tv.