tuf x570 aint too tuf part II

[tiliarazzi]

asus tuf x570 plus
ryzen 9 3900x
asus GTX 970
corsair vengeance LPX 32GB ram
evga supernova 550w PSU
120gb ssd


I power on computer and windows 10 boots normally to ‘scenic’ login page.
Then when I press any key or click mouse screen gets black and computer is unresponsive.
Fans and LED’s remain on, and I have to turn computer off by toggling power switch on back of PSU.
Can someone please help me with this?

[tiliarazzi]

Now this really sucks; went to ‘safe mode’ and did the whole reset thing that took a couple hours, and now it does the same thing!
I have been using computers for 20 years and have never seen anything like this! I just bought all these parts new (except video card & ssd which had no problems) and now I am pissed!
Is there any way to tell WTF is causing this to happen?