Thank you so much for your reply Hutchinson. But I’m not sure about the test I should try. Do I have to do it with the power on, during the normal start? I’ve already changed the power board, with not any difference (I’ve got 2 power boards now!). I’m worried a part of the linear led lights are broken, but I’ve got no idea how to fix it, if it’s the problem.

this is what happens trying to turn on my tv