I have a Samsung Q60T (50") that has a black screen

Hello. I have a Samsung Q60T (50") that has a black screen and keeps restarting. I tryed the tape method. First I figured that it stops restarting if I tape out the 15th pin from the large ribbon cable (counting from up to down). TV stays on but still has a black screen.

Then I untapped that 15th pin and disconnected the small ribbon cable connecting the two halves of the screen. It doesn't restart but still the screen is black.

After that I found that if I tape the first pin from the small ribbon cable (the shortest wire within the cable) it won't restart anymore, but the screen is still black.

Any thoughts?...thank you)