@MrOGZ My advice as former HP user myself - just through out this HP shit in the trash can, it's not worth of repairing. I tried, and it was not worth it, especially when its older then 3-4 years. And dont buy HP ever again (if it's not some gaming high price model) - the quality of their low cost or medium segment notebooks just dropped to the bottom over last 10 years.
(But I can assume that the display cable snapped bcs of opening and closing the top, it's not looking like video card is broken to me)
And thx for the translation.
@MrOGZ looks like physical damage to the screen. you can always use an external screen, or if not averse to fucking with it you can pray that its just a cable semidisconnect and take it apart to try reattaching the cable.
I've been there with my old computer, luckily for me it was the screen which actually looked a lot like what you have., but just cause I say that please don't take that as pro. advice.