Question Screen flickering on laptop?

[schiavoni]

Hello,

I had to clean up my laptop and add some new thermal paste to the processor of the gpu and cpu.
When I start start my laptop, I have some flickering on the screen.
The strange thing is that I can open a web browser in fullscreen and watch Youtube, without flickering. When going to the desktop screen, the flickering starts again.
Image
Video

I have tried to clean up the laptop again, but with no result. Does someone know what issue it can be?

 

[helpstar]

Is the flickering changing if you move the lid ?

check the cabling from motherboard to display

check with an external monitor/TV

 

[schiavoni]

Is the flickering changing if you move the lid ?

check the cabling from motherboard to display

check with an external monitor/TV

When moving the lid, the flickering isn't changing.
I've checked the cables a lot of times, but without a result. The TV does recognize that there is some connection, but without display.

 

[helpstar]

use windows + p hotkey to duplicate the display