Lg 50ln5100-ub

[dick_barton]

Re: Lg 50ln5100-ub

You only need to cover those pins that return the picture to normal. Try and keep as many of the pins in use.
I have seen this trick done but do not know what if any the long term effects are.

Post a picture of the final results of the screen.

[Diah]

Re: Lg 50ln5100-ub

Ok, the new t-conn came in this morning. Installed it, and of course the same problem which confirms a panel fault. I tried the tape trick. I had to cover 12 of the left tracks, on the right ribbon cable to get a normal picture again. Thanks jjannsen7 for the trick.

did you forget ? this was yours fault caused the taps of panel bad

I took a heat gun and heated around the edges of the panel with no change.

your first post photo there are horizontal line.. and your first test by release ribbon from panel one by one, you have clean white picture. also when you each time release these ribbon it will display different color line. those are enough to tell T_CON Fault .. try replace it before you caused more damage to the set.

to whom read this post later...

always 99.9% horizontal line on screen are T_CON or LVDS issue. panel don't have any to do with this fault.. only UHD TV of Samsung it would be panel fault.

[Fisher77]

Re: Lg 50ln5100-ub

You only need to cover those pins that return the picture to normal. Try and keep as many of the pins in use.
I have seen this trick done but do not know what if any the long term effects are.

Post a picture of the final results of the screen.

Thanks dick_barton. Anything other than tape I can use?

[dick_barton]

Re: Lg 50ln5100-ub

As I have said I've never done it, only seen Youtube videos. I would think the thinner the tape the better so as not to damage the connector when closing it down and to ensure you still have contact with all the other connections when closed.

[jjanssen7]

Re: Lg 50ln5100-ub

Thin tape is the best. I've done this to 30-40 different units and not have one come back (I offer warranty). I do believe it's a "bodge", but the only other option at that point is to toss the whole thing.

Sometimes the best you can do is get the picture to stabilize and have one thin horizontal line which I believe reveals where the short is.

In my experience it doesn't work for many tvs, especially those with flexible side tabs that extend out from the screen. Just a few LG, Sony and the odd Samsung that present with the problems you had. It's a last resort, after confirming that LVDS, Tconn and Main are in good working order.

Let us know how long it lasts!

[jondoe]

Re: Lg 50ln5100-ub

That horizontal tearing looks very similar to the problem I had on the one I just "cooked", it was the XD chip on the main board.

[jjanssen7]

Re: Lg 50ln5100-ub

When possible I've confirmed it was a panel problem. Swapped the main board with a known working one and had the same problem.

[Fisher77]

Re: Lg 50ln5100-ub

Ok, let me run this by you guys. With the ribbon cables connected from the
t-conn to the panel (no Tape), and I check the voltage on the 2 test points on the t-conn (with the red squares in the picture), they both cycle constantly from +30V to -4V. Everytime the voltage cycles, the picture changes on the screen, but there are still lines on the screen at both voltages. With the ribbon cables disconnected from the t-conn to the panel , the voltage still cycles from +30V to -4V.

Now what I am wondering here is, if the ribbon cables are disconnected fom the t-conn to the panel, doesn't that eliminate the problem if it were a panel fault?

If so, would that indicate a main board fault since the t-conn has been replaced, and the old t-conn was showing the same voltages when I probbed the test points on it?

[jjanssen7]

Re: Lg 50ln5100-ub

If there are lines on the screen with both voltages, doesn't that eliminate the voltage change as a cause/symptom of the lines?

[Fisher77]

Re: Lg 50ln5100-ub

If there are lines on the screen with both voltages, doesn't that eliminate the voltage change as a cause/symptom of the lines?

Damn, I didn't think about it that way. Good point jjanssen7.

[Fisher77]

Re: Lg 50ln5100-ub

Well it is taped now. I had to cover 12 tracks of the right ribbon cable. It still has a slight twitch in it, but with a movie going it is barely noticable. If I tape over 13 tracks, the twitch is gone, but it has a line on the screen.

Thanks jjanssen7 for cluing me in on the tape trick

Thanks for all the help everyone.