Envision H819: Any ideas to save this LCD panel?

[lexwalker]

Initial problem was no signal message then followed by no display when VGA signal is present. That was solved easily, but when the monitor came alive then was greeted by (aargh!) LCD panel issue. A quick look at the LCD panel, noticed a patch of weird black dust at one section of the output lead tab and tape carrier (not sure how that stuff even managed to get in there). After removing the dust, the source of the problem became apparent. For some reason, was that "black dust" corrosive? Even a few solder pads and through holes were literally gone...

See attached image for the damage. Those output leads are really tiny (under 0.5mm mostly). If one at a time then may not be hard, but the most difficult part is the group of 4 to 5 of them together (next to each other). Any ideas on how to deal with those?

[Davi.p]

Re: Envision H819: Any ideas to save this LCD panel?

You can try with silver paint (few dollars on ebay, don't buy "wireglue" it's a robbery) and a very sharp tip. first you must remove green paint/laquer on tracks with finest glassed paper

[mmartell]

Re: Envision H819: Any ideas to save this LCD panel?

There is some experimentation going on with 3M conductive tape but nothing solid atm.

[lexwalker]

Re: Envision H819: Any ideas to save this LCD panel?

You can try with silver paint (few dollars on ebay, don't buy "wireglue" it's a robbery) and a very sharp tip. first you must remove green paint/laquer on tracks with finest glassed paper

At first had considered conductive pen but the finest tip at 1/16 inch (roughly 0.8mm) is still greater than 0.5mm required. Perhaps can try using a mask to reduce the width. Already looking into that silver paint, but not sure if that "wireglue" meant the syringe thingy. Maybe you can point it out, as to which silver paint product...

There is some experimentation going on with 3M conductive tape but nothing solid atm.

Worse with tape as I can't cut that fine (literally a hair's width). Check out the image attached...

[mmartell]

Re: Envision H819: Any ideas to save this LCD panel?

No need to cut, you just need exposed metal on both sides. It conducts only in parallel lines.

[Davi.p]

Re: Envision H819: Any ideas to save this LCD panel?

Yes is the syringe type is the right thing, with very few product inside, wireglue is a white can/bottle with black paint in it, don't buy it. you use a sharp tip to place it on.. bye

[lexwalker]

Re: Envision H819: Any ideas to save this LCD panel?

Update: After a continuous 20 hours of tinkering (including much eyestrain and some frustrations) and hard work, finally saved this monitor from becoming land fill material. Finally figure out a way to deal with that group of 5 broken/corroded superfine traces (each about the width of a hair). And I wasn't using conductive pen nor silver conductive paint...

[selldoor]

Re: Envision H819: Any ideas to save this LCD panel?

Good fix -

[Davi.p]

Re: Envision H819: Any ideas to save this LCD panel?

Wow good work, but the picture is not so explanative, you have fix them with tin? I have a cutted FPC (ribbon connection) from a 37"lcd tv with 3/4 traces cutted, i have done tests on a unuseful FPC and restore connection with flux and tin, maybe the presence of flux let the tin not to do the wanted bridge.. so have you used flux?

[mmartell]

Re: Envision H819: Any ideas to save this LCD panel?

I can't see how he did it. A little explanation might be helpful.

[lexwalker]

Re: Envision H819: Any ideas to save this LCD panel?

Good fix -

Never thought it could be done. Notice that with those single standalone broken traces I have little trouble to fix. But do notice the size of the wires compared to the traces. That brown wire is the usual wire used for repairing and patching PCBs (with very thin hardy insulation), which is already quite thin/tiny and yet looks monstrous against the group of 5 broken traces. No way I could put these side by side. Then I used a single bare strand from a multicore wire for the other standalone broken trace. Still a little too big (will touch each other side by side). After some searching finally found a super thin bare strand from the shield of a RF coaxial cable.

Wow good work, but the pitcure is not so explanative, you have fix them with tin? I have a cutted FPC (ribbon connection) from a 37"lcd tv with 3/4 traces cutted, i have done tests on a unuseful FPC and restore connection with flux and tin, maybe the presence of flux let the tin not to do the wanted bridge.. so have you used flux?

Nope, solder bridge does not work. The iron tip is too big. Mine is already around 0.3mm and yet not good enough. Solder get mess up all over the place creating shorts between traces. Need an iron that has literally the size of a needle point to work this problem, but can't find any in my arsenal of that tiny. Tools for the solution was...

- Jeweller loupe with 15X magification (higher is better). Meanwhile my all other usual magnifying tools were useless (those usual 2X, 4X and 5.8X ones)
- Snap-offf blade knife
- Fine tip soldering iron, at least 0.5mm (smaller is better).
- Soldering flux
- Isopropyl alcohol
- Micro-cutter
- Flat head test pen or small flat head screwdriver
- Polyimide tape and paper tape (after my polyimide tape ran out). The paper tape did burn (became blackish) but held up well. Do not use cellophane or any other tape than can deform with heat.

The trick is the usage of the tape itself. Used quite an amount, with many pieces of tape per connection (at least 6 pieces). Used it to prevent the iron from affecting the neighbouring already finished repaired trace. Trust me, had headaches with my iron picking up the wire bridge accidentally all the time. It was so tiny that I didn't notice it until I re-checked again. The wire bridge picked up was nearly invisible at the iron tip (with my bare eyes)...

Sometimes it took me up an hour just to put these pieces of tape into place. And up to half an hour to prepare the wire bridge itself (to make sure all is ready before applying the iron)...

[Davi.p]

Re: Envision H819: Any ideas to save this LCD panel?

I hope i have understood, translating is difficult for me, you said: "a single bare strand from a multicore wire" do you mean a single cable from a multi cable cable (sorry i have to repeat cable) or a single wire (filament) from a little cable (or call it wire if you want, with insulation)

[lexwalker]

Re: Envision H819: Any ideas to save this LCD panel?

I can't see how he did it. A little explanation might be helpful.

If you look at my earlier quote...

At first had considered conductive pen but the finest tip at 1/16 inch (roughly 0.8mm) is still greater than 0.5mm required. Perhaps can try using a mask to reduce the width....

That was the reason for many pieces of tape, to create a mask so that only a tiny area is worked on (thus the iron tip will not affect neighbouring traces and other soldered stuff) . Also I used the tape to hold down the super thin/tiny wire. Pretty hard work to put all the tape into place, as the width of the opening/window (for the iron) is literally a hair's width (thus many adjustments required, often have to peel the tape off again to move it).

I hope i have understood, translating is difficult for me, you said: "a single bare strand from a multicore wire" do you mean a single cable from a multi cable cable (sorry i have to repeat cable) or a single wire (filament) from a little cable (or call it wire if you want, with insulation)

Perhaps I should have said a single filament from the outer conductor of the coaxial cable, or a single strand from a multiple strand core wire. See attached image. Also a close up of the area and the wire relative sizes. After tinning that super thin wire, it got a little thicker though...

[Davi.p]

Re: Envision H819: Any ideas to save this LCD panel?

Anyway thanks for posting the pictures of result and you gave me an idea for my case..