Chosen Solution
I have an LG 60SJ850T television. Half of the LED backlights have stopped working. The screen is displaying images but the right side of the screen is dark. I have taken the TV apart and the backlights on the left of the screen are working well but none are coming on at all on the right side. Connections to the boards all look good. No obvious blown capacitors on the PCB. The PCB has an output for the left LEDs and the right LEDs so I wonder whether this component of the PCB is faulty or whether it’s the LEDs themselves. Any advice or suggestions on further tests to do would be much appreciated.
It looks like you should be able to measure the voltages on the pins of the two LED connectors. (But keep fingers WELL AWAY from everything on the other side of that dotted line running across the board - that’s where live mains lives - and it might be hiding in one of those capacitors even after unplugging!) If the voltages on the connectors are similar it would indicate a fault with the LEDs themselves but if they’re different, a fault with the logic board. If the latter, look on the other side of the logic board to see where the circuit traces go, and hence which components generate them. By even closer inspection of that area and comparing the components supplying the two sockets there’s just a chance you’ll spot a bad solder joint or suspect component. If it appears to be the LED string at fault I’m not sure how repairable that will be but if you can access them you may be in with a chance.
