LG 50LA6200-UA - LED Problem

[rajat]

Hi everyone,
I have a 2013 LG LED TV - 50LA6200. LG logo comes for 1 sec then no picture, continues to have sound, Flashlight test shows a dim picture.

I need your help in figuring out if its the LEDs or the power supply (pic attached EAX64905501 (2.0) REV1.0) that needs changing.

Here is what my goofing around tells me.
With LED wire connected or disconnected to the power supply
Led+ (1 - Left on the connector)) Voltage - Goes to 170+ when backlight switches on then stabilises to 78
Led+ (2 - Right on the connector)) Voltage - Goes to 120+ when backlight switches on then stabilises to 78

I then disconnect the left LED wires (+ & - ve) and the return voltage on right (EL68) says 6.1. Doing the same on the right LED wires the left side retunr voltage (EL67) says 15.1

Now to further complicate it, while i was tinkering around, the backlight did come on and stayed for 45 odd mins. Sharing a picture of 3 black spots while the backlight was on. While it was on, the voltage on both LED+ read 123V.

In Singapore, DIY options are far and few in between and hence i want to be absolutely sure before i order parts. Seek your guidance to understand whether i should be replacing the power supply or the LED strips.

Please note, that i am not an electronics expert but can follow basic instruction and swap out non-electronics parts.

[yohnsee]

Re: LG 50LA6200-UA - LED Problem

Hello rajat,
the measures, tv behavior and the 3 black/dark spots tells me it is LED problem for sure.
You need to disassemble the whole screen to get to the led strips, it is not hard but on a 50" you have to be very very careful not to break the display or overstress anything.

[neilc6]

Re: LG 50LA6200-UA - LED Problem

Yes your picture shows 3-4 shorted LEDs. Watch some youtube videos on strip replacement for a LG TV. It's also handy to get the replacement strips first since you may forget how it all goes back together if your tv has been sitting disassembled for weeks waiting for the parts to get in. Once replaced, update the firmware and set the backlight level to between 50-70 for all inputs.

[rajat]

Re: LG 50LA6200-UA - LED Problem

Hi Yohnsee and neilc6....thanks for the advice! I suspected it was the LEDs.

Should i definitely be using suction cups to lift the panel up or just careful hands should do? This will be my first time handling an LCD panel.

[yohnsee]

Re: LG 50LA6200-UA - LED Problem

Hi Yohnsee and neilc6....thanks for the advice! I suspected it was the LEDs.

Should i definitely be using suction cups to lift the panel up or just careful hands should do? This will be my first time handling an LCD panel.

Both should do fine. I prefer using the cups with such big screens.
But if you have a big table, you can lay it down on its face (on a soft cloth) and disassemble from the back. Then, you can lift up the back metal chassi with the leds when every screw and retaining clips are out of the way. Look out for the flexible pcbs on the screen sides, they are very fragile and can not be removed, nor repaired if something goes wrong. You can ruin the whole screen if not paying enough attention. Believe me, I was there once

[rajat]

Re: LG 50LA6200-UA - LED Problem

Great advice... since most videos disassemble from the front, i would rather do that for the sake of knowing what to do... will also try order suction cups locally...
Will soon share what happens next

[rajat]

Re: LG 50LA6200-UA - LED Problem

Hello guys.
it took a while for the LED backlight to get delivered. I had ordered the entire kit since i thought why risk another LED failing and needing to open the TV all over again. I had also ordered for two suction cups to lift the panel up.

Did the LED swap today. As expected, the dark circles meant 3 LEDs were not lighting up. Replaced the entire bank of LEDs and put everything back together. All LEDs are firing now and TV works perfectly upon assembly.

Thanks for sharing your opinion and pointing me the right direction. I thought of sharing the result for the benefit of forum members.

For reference, i ordered the LED kit from https://www.ebay.com.sg/itm/New-kit-...72.m2749.l2649

[budm]

Re: LG 50LA6200-UA - LED Problem

Good news, just make sure to turn down the backlights level to as low as possible on all inputs.