LG LE37LH4000-ZA Tcon Issue?

**Diah** · 05-07-2016, 03:48 PM

Re: LG LE37LH4000-ZA Tcon Issue?

hair dryer temperature never reach SMD soldering, use hot air gun. maybe help more. don't use yours air hot Often as you wrote at same case with other users post.

**vinceroger69** · 05-07-2016, 03:53 PM

Re: LG LE37LH4000-ZA Tcon Issue?

maybe worth trying freeze spray too as you can find the problem area quicker sometimes, but tab bond issues can be fixed budm has some that been running a while i think on his own sets.

**dick_barton** · 05-07-2016, 04:16 PM

Re: LG LE37LH4000-ZA Tcon Issue?

That's my thoughts too. Use the heater to warm it up and get it going and the freezer to isolate the area of the fault.
However I have to leave it for now to one side and tidy up since I will be away for a few days but will pick it back up on my return.

**dick_barton** · 05-08-2016, 06:25 AM

Re: LG LE37LH4000-ZA Tcon Issue?

Since warming up the tab-panel circuit strip I've been unable to bring back the original fault no matter how much flexing, pushing and twisting of the set.

The back cover is on and it's behaving itself perfectly. Will run it for a few days and see if it reverts back to it's earlier fault.

The only conclusion I can reach is perhaps the tab-panel board was damp and warming it up has dried it out, Can't think what else could have done it.

**ReeceyBurger123** · 05-08-2016, 11:03 AM

Re: LG LE37LH4000-ZA Tcon Issue?

Press down on each tab driver see which one cures the issue.

**dick_barton** · 05-08-2016, 11:12 AM

Re: LG LE37LH4000-ZA Tcon Issue?

Hello ReeceyBurger123
The set is currently behaving itself 100% even when attempting to flex the screen. No amount of pushing and shoving the set affects the picture at the moment which remains perfect.
I'm away for a few days so will check it on my return.

**dick_barton** · 05-15-2016, 10:12 AM

Re: LG LE37LH4000-ZA Tcon Issue?

Looks like time to scrap this set but before I do has anyone done this as suggested by another Forum user.

To test Tcon jump 12v from SMPS to the Tcon fuse. Disconnect the LVDS cables Jump VCC 3.3v to the LVDS(CN1) connector ground pin. Apply ac to power supply, patterns of White, Red, Blue, Green should appear on the screen.
Voltages can be read at the ribbon connector or at test locations on the board (typical 16.74V, 3.3V, -5V and 28V)

Could anyone confirm whether or not this test works?

Just removed one tcon connection and then replaced it and then removed the other and for each test the picture was only seen at the very top of the screen. With both tcon cables re-installed the set is virtually picture perfect.

Out of curiosity does anyone know what the white milky stuff is that can be seen under the COF chip?

Attached Files

**comptek** · 05-16-2016, 09:41 AM

Re: LG LE37LH4000-ZA Tcon Issue?

was this the one with water damage ?
could be residue thats dried ?
use a soft rubber and clean tcon cables following the line they run not accross then wipe to remove rubber particles

**dick_barton** · 05-16-2016, 10:03 AM

Re: LG LE37LH4000-ZA Tcon Issue?

Hi comptek,
I'm not aware that there was water damage but that does not mean there wasnt. It does look like water vapour but the COF chips run hot so I would have thought that would be the dryest point on the cable. I've shelved it for now and will look at it another time.
Thanks for the tip.

**ReeceyBurger123** · 05-29-2016, 03:05 PM

Re: LG LE37LH4000-ZA Tcon Issue?

I have the same Panel here same issue, I think I have a leaky ceramic cap on the tabbond pcb as when I freeze them it works fine when heated I get loads of lines. Going to keep testing.

**dick_barton** · 05-29-2016, 03:48 PM

Re: LG LE37LH4000-ZA Tcon Issue?

I'll be interested in the results except I have the problem in reverse. Warming up and it will run fine all day.

**ReeceyBurger123** · 06-05-2016, 06:35 PM

Re: LG LE37LH4000-ZA Tcon Issue?

I sorted the issue with mine DB

Guess what the fault was, not the panel or the Tcon but the flat flex ribbon cables that link the Tcon Lvds signals to the panel. Upon close inspection of the one I had the pins at the end seemed to be a little broken/detached from the rest of the copper. I think its because of the alu tape around the cable as mine was at the end surprisingly next to where the copper pin was broke.

I had some spare so I swapped both out and boom the set it fixed perfect image every time even from cold and after being left on for hours