Black laptop screen?

I have a laptop that until recently was always connected to a PC via an HDMI cable. If the two were separated, the laptop continued to run on its own without any problems. Now all of a sudden after the laptop was off the screen was black and I could only see something on the TV screen when I connected the laptop to it via Hdmi. I've tried all possible key combinations that I have a picture on the laptop again, but without success. Then I just turned on 3D to try everything out, but I only see colorful stuff on the TV screen (see picture) and the laptop is still black regardless of whether it is connected to the TV or not.

Win + p

Habs tried unfortunately doesn't help either😕