Chosen Solution

Which board controls my video display? Opening the back panel I have a: Main BoardTUS BoardLDHM Board The TV internals look exactly as this YouTube video. https://www.youtube.com/watch?v=zqDEoDZq

Did some looking around, and the problem may be being caused by your Main board.

Teerev that is why it is important to post images of your TV. That way we can see what you see and we can always help with the identification of boards , parts etc. Remove the back of your set and take some pictures of the layout as well as the different boards. Use this guide https://www.ifixit.com/Guide/Adding+imag… that. It will allow us to see what you see. Then start by using a Triage method, determine which could be primary cause and which could be secondary. Something like this

after that proceed with a general approach to the troubleshooting of No Video like this

The rest will then depend on your findings. BTW your set has a T-con board and I do believe it is actually behind your BAXL board (for now my money is on a bad T-con board ;-)