I’ve been experimenting with a defunct 55” LG LED tv. For which I have no schematic. Initial failure was screen black, no picture. I’m trying to learn here. I believe the black plastic panel which connects to the Timing Control Board is a multi array of LED filters. Is this panel the name sake for the tv (LED or LCD)? Is the black light array a preset brightness used as a light source, or is it supposed to vary with the video signal? I found several White LED’s shorted and some open. I set all the boards up bread board fashion, and have a channel tuned and sound without a display. Further investigation I found their are two supplies feeding the LED assemblies connector. Outputs are labeled LED1, + & -, and LED2, + &-. I measure zero volts across the respective +& -, connector terminals. However I measure +80 volts from the respective + to circuit grounds with a resistive load. The owners manual indicates there is a black-lite adjustment in software. I’m assuming there is a current limiter circuit in the negative rail of the supplies and this path is open. Is anyone familiar with this circuit, am I on the right path?