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

[tom66]

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

As Freak shows you will need to remove the bonds from the panel and not just the board itself, unless you can find some way to isolate them without removing the bezel it's going to have to come off...

Nice to get confirmation that this hack works. If it were me I would add some heatsink compound to the gate drivers and attach them to a metal heatsink if possible - this may improve lifespan

[budwich]

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

To recap the side of the screen that is having problems is most likely the gate driver is on that side and those are what I carefully peeled off of the LCD panel. You cannot remove just one you have to remove all of them so therefore the boards are no longer connected to the bottom flat ribbon cable that goes from the bottom of the panel to those boards. You can leave the ribbon cable in there if you like but there will be no more ribbons and no more boards on that side of the panel that has the defect to recap the side of the screen that is having problems is most likely the gate drivers on that side and those are what I carefully peel off of the lcd panel. You cannot remove just wanted you have to remove all of them so therefore the boards are no longer connected to the bottom flat ribbon cable that goes from the bottom of the panel to those boards. You can leave the ribbon cable in there if you like but there will be no more ribbons and no more boards on that side of the panel that has the problem. For me it was the right side first tab on the lower right side board of the panel..


Before and after

freakaftr8... thanks for the guidance. Just to clarify, my 70 in has two edge board on each side. The lower board / subtending flex cable is likely the one causing problems. It has two flex cables connecting it to the panel. You are saying that I have to remove both those flex connection / gate driver's at the panel. I was hoping to leave the others (upper board) alone. further, I might try get my hands on a broken lcd panel for a test operation just to get an idea of how hard this is going to be.

Further, this is a 70 in panel (ie. big). I have been working with it flat on a "bench" with boards going across the bench (from top edge to bottom edge on the bezel) to support the tv as the bench surface is smaller than the screen. This way the screen can be seen around the sides. If I remove the bezel completely, then the screen itself will have to be laid out on the bench. Is this correct? Will the screen be strong enough to support any overhang that is not supported once the bezel is removed?

[freakaftr8]

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

That is correct the 70 inch I repaired also add flex cables connected to the right and left side as well. The offending side of the panel with the problem is the side that you need to look into with the flex cables connecting to the side of the panel.

As to removing one or all if you remove one you have to remove every single one of them on that side unfortunately..

freakaftr8... thanks for the guidance. Just to clarify, my 70 in has two edge board on each side. The lower board / subtending flex cable is likely the one causing problems. It has two flex cables connecting it to the panel. You are saying that I have to remove both those flex connection / gate driver's at the panel. I was hoping to leave the others (upper board) alone. further, I might try get my hands on a broken lcd panel for a test operation just to get an idea of how hard this is going to be.

Further, this is a 70 in panel (ie. big). I have been working with it flat on a "bench" with boards going across the bench (from top edge to bottom edge on the bezel) to support the tv as the bench surface is smaller than the screen. This way the screen can be seen around the sides. If I remove the bezel completely, then the screen itself will have to be laid out on the bench. Is this correct? Will the screen be strong enough to support any overhang that is not supported once the bezel is removed?

[budwich]

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

freakaftr8... one more question. By any chance, during your "troubleshooting", did you try "freeze spraying" the area area in question to see if it had any impact on the picture to perhaps indicate which flex cable / gate driver was an issue?

PS... I see that we "crossed in time"... OK... so all the right side flex cables need to be removed (5 - three upper and two lower). :-(
I assume there after that the edge boards are left in place (ie. interconnected and connected to the bottom edge board).... or are they totally removed?

[tom66]

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

This kind of operation is best done face up. Once all screws securing the bezel are removed the bezel should just lift off and then the metal framing/shielding can be removed exposing the tab bonds (gate and source drivers)

Since your fault is intermittent I doubt freeze spray will have any effect

[freakaftr8]

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

Agreed this kind of operation cannot be performed unless the TV is face up that you can get the bezel completely off the front. Yes I did try freeze spray it first and it did not do anything at all. The problem is simply that the tab driver has gotten too hot and has separated itself or de laminated itself from the driver tab bond. At least that's what was going on with mine with yours you may have a different situation where if you press on the tabs it doesn't change anything because ofdrivers upt shorted internally

[budwich]

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

face up means that the boards all have to be removed.... or can the back side panel have blocks strategically placed in the various quadrants to support the panel off the boards?

[freakaftr8]

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

No no not at all find a large area where you can lay the tv down face up all you have to do is remove the plastic trim bezel around the TV screen perimeter you leave the screen inside the TV you do not need to support it what you need to do then is pull off the side metal frame from the screen bezel on this particular panel the side frames are probably black and the top and bottom frames are silver you only need to remove the side frame of the offending side of the TV screen in order to access the side driver boards

If you can lay the TV down on carpet face that nothing is going to hurt or harm those boards that are still in the TV you do not need to remove them as they will be fine

[budwich]

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

from what I can see, there are screws holding the bezel all the way around. Then there are also finger "tabs" that have to be "unlocked" / pushed to get the bezel off. So basically, you are saying undo all the screws, then place the tv face up on a carpeted area and then release the tabs and lift the bezel off?

see the attached picture... hopefully you can see what I am referring to in terms of bezel mountings.

[vinceroger69]

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

budwich just remember as we have said theres no gaurantee this will fix your fault, and once you have removed the tabs etc they cant be put back on so this could make the set act worse. theres also a chance you could crack/damage the lcd i dont want too put you of trying this fix as it may work you just need to be aware of the risks even more so if its a tv your repairing for someone else. saying that though just take your time and ask and maybe upload pictures if your stuck and we will try too help.

[budwich]

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

I understand the risk. It isn't much. Its going to the "recycle" if I am not successful so the risk is minimal that way... I just don't want to have to clean up a significant mess if the things "implodes" in some fashion. My neighbor is already telling me to give up and just chuck it. I am taking it as a learning opportunity for the future (touch wood... not my future... :-) ).

Based on the great help / pictures so far, I am certainly game to try it.... so it is a go. The only stop might be if the recycler has restrictions on what they will take if it is "significantly damaged" with charges / extra charges ... don't know.

[tom66]

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

Nawww, they really don't care what you recycle. I dropped off a smashed Pioneer 6G 50" plasma that had a completely shattered screen and held together with duct tape. The guys there asked me if I lost at FIFA!

As for the bezel you need to remove the screws, loosen the bezel then flip the TV over so you can access the panel itself. On an insulated surface the set should operate fine.

[vinceroger69]

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

well if it dosnt work you can salvage the boards and led strips etc for another project you might even make a bit of profit selling the boards on ebay etc.

[freakaftr8]

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

Tom I have a question for you when you disconnect the power from the right side tab drivers and you have a screen on that right side is dark and smearing. Isn't that usually due to the power loss on the right-hand drivers thus for their draging the load on the left-hand drivers putting an extensive load on them because they're carrying dead drivers on the right also?

Wow vinceroger69 check out how many posts you made compared to me lol same number.

[vinceroger69]

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

yes just saw that now lol, hows the repaired set is it still running? im curios to how long they will last as you dont if at all hear of anyone attempting to fix this problem.

[tom66]

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

Yeah - something like that. The idea is that the driver has internal diodes on the output which are being biased and the driver is being back-powered this way. Hence why the whole driver needs to be removed, not just disconnected from the PCB.

[freakaftr8]

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

That's exactly what I was thinking as well.

TV is still working perfect.

Yeah - something like that. The idea is that the driver has internal diodes on the output which are being biased and the driver is being back-powered this way. Hence why the whole driver needs to be removed, not just disconnected from the PCB.

[budwich]

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

But I still have that nagging question about whether it is necessary to remove all the tabs or just the two associated with the lower half. I guess it doesn't matter since it appears that connecting the edge boards back up to complete the remaining circuitry doesn't help anything... does it?

[freakaftr8]

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

To answer your question yes if you remove one tab driver on the panel on that side you must remove all of them.

[freakaftr8]

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

Again here's what you're going to end up with when your job is done