Question "Blue" monitor or coloured stripes on monitor after boot

[wossnameX]

Hi.
Intel Core i7 6700K/ASRock Z170 Gaming K6 /Fata1ty)/32GB DDR4/GTX1080

I have bought a Radeon HD 7950 used, and the card works on boot/windows start, but as soon as I DO anything (Click the Start-button, anything really) the screen goes blue og multi-coloured stripes vertically.

I suspect a HW problem on the card, since the machine works perfectly fine with a GTX1080. Most likely a memero problem, if my memory (sic) serves me right.

What say you?

 

[Heavybtakingowa]

Guaranteed a HW problem, since the other card works fine!!§!

I had losts of problem with Sapphire before, I hope it's not a Sapphire card!?