65UJ6200 unable to get backlights on

[lfhlaw]

I was able to get my hands on a LG 65UJ6200 with no backlights.
Flashlight to the screen will show an image so I'm assuming the Panel is still okay.

I can also hear sound as well.

I replaced the LED strips with new ones.

Tested them with the light tester.

The LED Voltage at the pins will jump to about 340 or so at pin 11 and 12 when the TV is turned on but then drops. There is also a slight flicker with power on which is typical for bad LEDs. Interestingly, when I try to test the LED pins it appears due to the wiring, that I cannot just drive the LEDs with a test based on adjacent pins( I.e. 11-12, 8-9)

I've looked at the Capacitors on the Powerboard and no bulging. Nothing stands out to me at the moment. Part of me feels it is still the PowerBoard, but unsure.

I'm kinda stuck as where to look next.

[R_J]

Re: 65UJ6200 unable to get backlights on

You have a problem with the backlights, likely a bad connection on the distribution strip or at the plugs in the panel. to drive the strings you need to connect between LED1+ and LED1-
I think your meter is being fooled by the unfiltered dc voltage to the led strings, also without any load the voltage will be high.

[lfhlaw]

Re: 65UJ6200 unable to get backlights on

You have a problem with the backlights, likely a bad connection on the distribution strip or at the plugs in the panel. to drive the strings you need to connect between LED1+ and LED1-
I think your meter is being fooled by the unfiltered dc voltage to the led strings, also without any load the voltage will be high.

well found a replacement distribution strip on Ebay and will see if that works. I did, at one point, get a replacement power board but it did nothing for the LEds.

[R_J]

Re: 65UJ6200 unable to get backlights on

well found a replacement distribution strip on Ebay and will see if that works. I did, at one point, get a replacement power board but it did nothing for the LEds.

It may just be a bad solder connection on one of the plugs, You can work on the backlights without having the LCD panel installed, after replacing backlights you should always make sure the backlights are working before reinstalling the lcd panel, this way there is less risk of damaging the panel.

[lfhlaw]

Re: 65UJ6200 unable to get backlights on

Well I did replace the harness to LEDS and that didn't work.

I Did however, get a T-con Board that got my lights back on.
I put the TV back together and still had picture but after about an hr, the lights went again and now i'm back to picture being produced but no light.

I'm guessing the Power board is bad and shorting the T-con? So I ordered another T-con and Powerboard from Tvpartstoday and that didn't seem to fix the issue.

Crazy that I had picture for maybe an hr and then it went kaplooey again.

[Diah]

Re: 65UJ6200 unable to get backlights on

you have different at T_con firmware and main firmware..
send in_stop to reset the tv to factory mode... search over here in_stop
if this didn't help try to update.. if no update then downgrade with pc Apache server for lg.

[lfhlaw]

Re: 65UJ6200 unable to get backlights on

you have different at T_con firmware and main firmware..
send in_stop to reset the tv to factory mode... search over here in_stop
if this didn't help try to update.. if no update then downgrade with pc Apache server for lg.

not sure what the "in_stop" is? is that a typo or was it supposed to be a graphic?

[Diah]

Re: 65UJ6200 unable to get backlights on

i wrote search over this forum in_stop command for lg.... no typo,,, it IR code command send by service RC.. but if one don't have one there are alternative method to send the command from diy or mobile phone with IR sender