LG 50LN5750-UH horizontal lines

[Iceman_GER]

Re: LG 50LN5750-UH horizontal lines

what about those 4 wires going to the LCD ? Little plug top of the board.

[tom66]

Re: LG 50LN5750-UH horizontal lines

They are for the LED backlights.

[Iceman_GER]

Re: LG 50LN5750-UH horizontal lines

I may just order a mainboard and see if I get lucky.

[tom66]

Re: LG 50LN5750-UH horizontal lines

That would almost certainly be a waste of money.

[Iceman_GER]

Re: LG 50LN5750-UH horizontal lines

you also think it's the screen?

[50LN5750]

Re: LG 50LN5750-UH horizontal lines

test

[50LN5750]

Re: LG 50LN5750-UH horizontal lines

I have this same model that I have put new LED strips in. The tv worked fine and clearly for about 1 hour, then the image started shifting and had lines in it. Now it is permanent. I have taken photos to demonstrate the shifting from clear, to lines and back again. My next move may be to remove all capacitors on the power board, replace them with fresh ones and try again. Unfortunately I am not sure since it may be the panel. I'm posting for professional advice before I put more time and money into this set. I have a multimeter and soldering iron.

[budwich]

Re: LG 50LN5750-UH horizontal lines

it appears that you might have damaged the panel during the effort. :-( If the set has side tabs, you should check those to ensure that the disassembly / reassembly was done correctly and they haven't been "crunched" in the frame some how. IF no side tabs, then perhaps the "tape cutoff" method can be used to save the panel assuming the issue is only on one side.

[50LN5750]

Re: LG 50LN5750-UH horizontal lines

Just removed the metal frames and re-examined the tabs, they are all along the bottom of the set.

[50LN5750]

Excellent success!

perhaps the "tape cutoff" method can be used to save the panel assuming the issue is only on one side.

The tape method worked for this model! Refer to picture so you can see where I applied the scotch tape. What I really don't understand is WHY this fix works? Anyone have a technical explaination? Grateful for the help budwich!

[50LN5750]

Re: LG 50LN5750-UH horizontal lines

Tada!

[budwich]

Re: LG 50LN5750-UH horizontal lines

good effort.... it works because the method cuts off signals / voltages going to one side of the panel (that deal with the horizontal picture "elements"). On sets with no side tabs, the drivers are "built in to the glass panel".... by cutting off the "powering", those drivers remain turned off and don't impact the drivers on the opposite side. That's my take on things.

[50LN5750]

Re: LG 50LN5750-UH horizontal lines

*Update* For anyone attempting this tape fix for their tv, I found the best results for zero lines in the picture is to skip the first two pins on the cable, then cover the following 5-7 pins. I honestly don't know how many pins I covered, it was trial and error, but it was not more than 11 total. I just know that I stopped immediately and sealed it back up when I had a good result.

[50LN5750]

Re: LG 50LN5750-UH horizontal lines

Bad news on this repair, the line has re-appeared after about 50 hours of use. Anyone have any new suggestions? Now it seems un-watchable in this state.

[budwich]

Re: LG 50LN5750-UH horizontal lines

think you might try "adjusting" the tape to see if you can change things.

[50LN5750]

Re: LG 50LN5750-UH horizontal lines

Are there any specific guides for this issue and model? For example, cover only the first 5 pins, 6 pins, 7 pins, skip over the first one or two pins etc? I get nervous each time I do this because I'm risking damage to the connector each time I handle it...

[budwich]

Re: LG 50LN5750-UH horizontal lines

I have seen any but in general, it is likely that it is preventing powering going to the side drivers that in this case are built into the panel as opposed to tabs on other types of set. I would suggest not skipping any and keep adding width til the problem goes away. As long as the issue stays related to one side, I think this is your only bet. You might be able to "guess" based on the track traces that are coming towards the connector. With every connected (no tape), no power (not plugged in), get a meter and do a resistance measurement at the test points that you pictured earlier. Compare those measurements with those of the other side... hopefully they exist there in similar fashion. Go from there.