Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

[tom66]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Yes. The drivers chain data to each other so if only one is removed the others will malfunction and output incorrect data which might cause more damage

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

ok... that's a good tidbit.

Its going to take a bit to do this as my "helper" works more than he watches... but I hope to get this done this week, hopefully.

[mmartell]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Wow this is a fascinating find. Is this then applicable to other panel manufacturers or is it more dependent on the quality of the drivers used ?

[tom66]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Most newer LCDs don't use gate drivers on both the left and right. Some big panels, and most older LCDs do so it might work. I think it should be a last resort though, and I'm not confident they'll work long.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Yes I have found gate drivers on all big sized Sharp LCD panels so far. The only reason I pulled mine off the right side is because the way it was failing. I noticed the spot where the gate driver on the right side was causing the issue when I disconnected the power cable to the gate drivers on the right side I still saw a one-inch section spanning across from the left to the right still looked normal where the rest of the screen was dark and blotchy on the right side that's why I realized that the gate driver still connected was causing a problem that's for peeling them off.

And by the way the TV has been on non stop since my find and still has an excellent picture. The gate drivers on the left side don't even feel significantly warmer than normal. But like Tom said we'll see how long this lasts as there is a significant amount of work having to go through the left gate drivers now they're having to work twice as hard.

[sleepingAwake]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Maybe it would be prudent to affix heat sinks to the remaining gate drivers.

[tom66]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

That's what I'm thinking. The power dissipation will be quadruple a single gate driver, because power is proportional to the square of current. Perhaps even higher depending on the capacitive load. It remains to be seen - I'm not sure what causes the gate drivers to fail in the first instance.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Hey SleepingAwake glad to see you on here!

He is dealing with a problem with a Vizio e701i-a3 model like mine using a sharp panel on another forum. Since these TVs are not manufactured by sharp they don't have the current limiting circuitry to shut down the t-con board with a 2-5 error code so the vizio model will keep going after the short in the panel takes down the voltage on the tcon until the tcon shorts out. He has the same issue as me it seems.

The only thing I notice about the original posters TV being a sharp Quattron 4 color 3d model where ours are just simply a standard 3 color panel non 3d. But it shouldn't be a major issue as those gate drivers are designed that way as well.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Reading all this about sharp panels now kinda scares me. I'm wondering if it's a matter of time before my 80 inch Sharp LC-80LE632U decides to bite the bullet. My kids watch netflix on it constantly. They call it the movie theater room haha at least i save a few bucks since i don't have to take them to the movies

[tom66]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Well increasing the number of horizontal pixels as in Quattron will increase gate driver power dissipation. 4K sets will be worse too.
Some Quattron sets have divided subpixels, 16 million vs 6 million typical subpixels. Must be a pain to drive those kinds of panels.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Yes probably. I know my father in law has a 60 inch Quattron. The dreaded led failure model LC-60LE810UN. Its always on he never turns it off he leaves it on 24/7. It went down once in the top right led shorted and I bypassed it because I had nothin. it has been running fine for 2 more years. This is the earliest of quattrons. I do believe the shark put a significant amount of time into quality control back in 2010 to 2012 when the big panel manufacturing became into play. Not sure so much about now the panels and probably manufactured in China and Mexico where they were high quality Japanese back in the early stages of the big screen led.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Here are a couple good pictures I took of the original problem with mine and what it looked like with just the power disconnected from the right side gate drivers. See the middle of the screen where the strip is where it looked good but the rest was dark? That's untouched yet. That area of the affected gate driver on the right side was making a bad connection so the panel essentially looked ok there. That's why I discovered that removing the rest of the drivers would essentially fix it.

The second picture is the bottom right side gate drivers removed.

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

I got the set in position to work on it. It is raised up as dealing with it is easier that way. Hoping to play "dr. kildare" shortly.

One thing that I find interesting with the posts to date, is that it appears that the drivers seem to mostly fail on the right side... wonder why that it?

[sleepingAwake]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Oh boy.
This is the post I'm waiting for.

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

:-) my "shortly" might mean something a bit different than your expectation. I hope to get to it in the next couple of days but that depends on other "demands" :-)

[sleepingAwake]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Your killing me. :p

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

OK... it looks like "shortly" could turn into "longly"
HELP.

I got the bezel off.... lots of unscrewing as the bezel acts like an integral structure member holding the screen flat and "sandwiched". IF you remove any of the screws before you have positioned the screen in your "flat" work space, depending on how many are left on at the time, the screen will almost be like "toffee" bending quite a bit... surprise. I thought the back bracing and such would be more rigid. Anyways, I should have left more screws on.

The "HELP" is now that I have the bezel off, what next? It now looks scary. Access to the termination point of the flex cable tab is NOT readily available as it is goes under what I assume is the top protective screen of the "5 layer screen panel sandwich".
What do I do to remove or at least "slide" the screen over to get access to those points?
I am hoping I don't actually have to remove it but I suspect the "vacuum" effect will be great with that larger of a surface area. Dust is going to be an issue that I wasn't expecting to deal with (its my basement and it does have a work shop in there) as I was just expecting to deal with some form of "edge" only leaving the panel intact.

I don't want to proceed until I get some comments / understanding as to the best way forward.... thanks for this.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Double post. Look below.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Okay first of all what you're talking about disassembling is far and beyond what you need to do. You're already at the point we can remove those tabs they're bonded to the screen you do not need to take the screen out of the TV. You need to loosen the boards that hold those tabs to the frame they're two skinny green boards on that side. Make sure you got the proper side of the affected side of the screen. You need to carefully grab each of those boards starting with the upper board in carefully peel that cable of the screen from the top to the bottom of the screen. this should be done on this side that has the problem. If you look at my previous pictures I posted you will see what needs to be done.

[freakaftr8]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

By the way the first picture is showing the board still hanging off the screen but the ribbon cable had already been pulled from the scree. Those cables are physically bonded to the screen your purpose is to peel them off so they're not physically bonded to the screen anymore just on that side that is the bad side with the problem.

In your picture you printed that the tab goes under the screen technically it is a mirage it does not go underneath the screen. It is fused to the side of the screen and you can peel that cable up and away from the screen