LG TV no image. Already replaced LED panel

So I have this LG TV (model: 47LN5790-UI) that I have replaced the LED back light panel this would be the third time. When I turn it on it flashes and then turns black. Sometimes I get the LG logo and I can see the image with a flashlight but sometimes is just black. I opened it again to see if I was missing something but dont know anything about TVs to know if there’s a problem. I did test the LED lights and the ones labeled as R1 and R2 (three of each) dont turn on unless I test the individual lights but all the ones labeled as L1 and L2 work.

I uploaded some pictures of the back and boards. I also noticed the cable that goes from the board to the lights the table looks burnt