Help me have a problem with the extended screen on the laptop?

I have a problem with my laptop and the extended screen funny way it shows me there are many moving stripes I thought it would be s.kabel so I've bought a new one (HDMI to DVI) but the stripes are still there who has Any idea what that can be?

Thanks in advance!

Have you ever tested the screen on another device?

But I'll do it right now

Nope. But if you've already swapped the cable, which would have been my first stop, it will probably be on the monitor itself. Or at the second GraKa Port.