LG 50la6230 backlight issue

[Maztrix]

Hi guys,
My Lg 50” la6230 has a backlight issue. Get the Lg logo but then nothing. Picture can be seen with a torch on the screen.

The voltage from the Power board to each led circuit has ~ 110 volts when turning the tv on and all the LEDs light up but drops to 78-80 volts on both circuits. There are no obvious burnt LEDs and I tested each One individually with multimeter and they are all intact. The voltages to the main board are all ok. I have swapped the power board out for another one with the same issues.

I have a feeling it is the backlights that I'm missing something on but not sure what it is??

Anyone have any suggestions?

[neilc6]

Re: LG 50la6230 backlight issue

You can power up the tv with the panel removed and video record the flash. If you go frame by frame, you should be able to see which ones are bad. Your multimeter isnt putting out enough current to properly test the leds. Better to replace them all with new since they all have wear.

[budm]

Re: LG 50la6230 backlight issue

Can we at least see the pictures of the backside of the TV showing all the boards?
What is the power supply board P/N?

[Maztrix]

Re: LG 50la6230 backlight issue

So I think I found the led with the issue. 3 strips not lighting up all on the same circuit. One Led looked a bit different to the others so popped the diffuser off and found this! When I tested the led on diode mode with the multimeter it was ok though? Was I doing it wrong?

Is it better to replace all the strips in that series or just the one with the blown led?

[budm]

Re: LG 50la6230 backlight issue

Better to replace the whole set of strips.