Hi @godfather17
Try the following to check if the screen LED backlights are working OK.
Disconnect the power to the TV and then remove the back cover from the TV.
Disconnect the mainboard-power board cable at the power board end only.
Reconnect the power to the TV.
The screen LED backlights should turn on full and stay on.
There will be no images because the mainboard has been disconnected.
If the screen seems faded or intermittently turns black then there's a problem with the TV LED backlights or the power board.
''***Be safety aware:*** There is ***exposed lethal AC voltage*** on the power board. Disconnect the power to the TV before working in the back of the TV.''