Laptop screen went black - can't find the case/ solution!

Hi guys, I'm new here and really hope I can get some help :)

I was using my laptop normally (Samsung np-sa31, Bremen - M motherboard), I turned it off, by pressing the power button and then closing the lid if I remember correctly since I was in a hurry.

After coming back to the device, the screen just wouldn't turn on! It just stayed black.

I tried everything. Messed around with the BIOS, reconnected the LCD cable, repositioned the RAM sticks and tried to run it with only one of the sticks, removed the CMOS battery and then placed it back, tried to clear static via power button, and much more, INCLUDING buying a whole new screen! The same problem still persists.

The laptop is fully working when connected to an external display via VGA cable, you can see everything on the screen when you flash with a flashlight on it (same for the original LCD and the brand new one I bought).

I have no idea what's wrong. I fully disassembled the laptop and I will add imaged of the motherboard, to me, nothing seems out of place and no fuses are burnt (the heat sink was removed for the sake of the photo), but maybe you guys will know what to look for and I'm just missing something.

https://pasteboard.co/ogkZ1xfYLAkd.jpg

https://pasteboard.co/P9Zqc2IouPl1.jpg

Thanks!

Windows / Chrome 113.0.0.0