One vertical green line on my AQUOS LC-70LE740E TV

[Bagel]

Hello,

on my AQUOS LC-70LE740E LCD TV there is a vertical green line on the screen. (pictures below)

Does anyone know what the issue could be?





Thanks in advance

Edit:


Up close it looks something like this

[wraper]

Faulty LCD panel.

[Bagel]

Thanks for the quick response! Yes it seems to be a faulty LCD panel. Is there anything worth trying before it goes to the dumpster?

Edit:
Factory reset did not work.

Edit2:
Youtube videos show LCDs with a vertical line being fixed by reinforcing the contacts. Might me worth a shot?

[Rasz]

Its still a 70" panel, Imo too big of a waste to just bin it. It has VGA meaning there is option of configuring custom resolution (1600x1080?) and moving picture to the right, you will end up with 50" PC ~3:2 monitor.

[james_s]

You could try gently pressing on the ribbon connections along the top and bottom of the panel in the area of that line, there is at least a chance that you have a bad connection there.

[wraper]

It's probably possible to somewhat fix it. I've had some success pushing driver IC onto the flex cable it sits on to restore the lost connection. When problematic area found install something that pushes it permanently. If you are lucky, it may last for a while.

[Bagel]

Thanks for the tips! I will ask my uncle Bob to take it apaaart with me and we will see what we can do. Im going to report on this here.

[mon2]

Post your issue and details on the badcaps forum for tv and monitor repair. There are many there who can confirm if the fault can be serviced.

https://www.badcaps.net/forum/forumdisplay.php?f=31

[Bagel]

Will do! Thanks alot! 

[Bagel]

When I loose the contact on the connection and apply different amounts of pressure I get this kind of artifacting (some of it looks just like the original vertical line. The original vertical line however does not go away when reconnecting):

[james_s]

Well that sucks. The fact that it changes when you press on it definitely suggests there is a fault there though.

I forgot to ask this but did you confirm that the set is out of warranty?

[Rasz]

you can also try pressing on the ribbon glued to the PCB under the connector

[Bagel]

Thanks for all the replies so far!

To be clear...
This is the connector fully engaged:

This is the connector fully loosened

This is one of the many artifacts that apear, when the loosened connector is lightly pressed down (notice the permanent line is brighter):

This is another one of the many artifacts that apear, when the loosened connector is lightly pressed down:


These artefacts are lines or plains that are white, blue, red or green. Next to that connector is another one that behaves the same as far as I can tell.

Another idea would be to replace one of the PCBs:


There is another one on the right of them but its covered by a metal plate. The whole housing is of metal, beautiful construction.

Maybe unplugging the cables on the pcbs and cleaning them would do the job? I have no clue about this stuff, but im feeling like dumpimg this high quality made in japan TV is a waste. Defenitly no warrenty on this one. Pressing the ribbon under the connector doesnt effect the screen at all.

[james_s]

Whatever you press on that affects what is on the screen has a problem, it's hard to tell from the description what that is.

[Bagel]

Whatever you press on that affects what is on the screen has a problem, it's hard to tell from the description what that is.

I lift this connection:

Like this:

[drhex]

Hallo,
it is perfectly normal that things change when the connector is open and you move the ribbon cable. Does the green line disappear when you disconnect the flat cable? If so, you probably have an issue in the driver section on the other side of the cable, the panel may be fine. If it stay no matter what you do the panel is probably shot.
Florian

[Rasz]

Leave that connector alone closed. Replacing boards wont help in this type of defect.
Problem is usually the ribbon bonded to the glass, its under your finger on the photo, under the ribbon plugged in connector. Its either bond itself of the chip on flex on it.





now im NOT saying you should whip out soldering iron and start burning stuff up! Take a credit card or something similar flat and stiff and gently run it side to side over the bond while monitor is running to see if your line changes

[james_s]

I fixed several old Game Boy handheld games years ago that had bad bonding to the glass. I put a piece of paper over the back and rubbed it with the tip of a hot soldering iron, they were still working last time I used them.

[Bagel]

Hallo,

I have disconnected the flat cable


The screen goes partly white masking/making disapear the green line.

I will now check the contacts with a plastic card.

Oh man, the gameboy is my favorite console. Ironically I had green vertical lines on mine decades back. Thought of buying one in 2008 when people where selling them for one euro...

[Bagel]

Went over the bond with my finger, that had no effect. Gonna try it with something stiffer.

There is another connection that goes straight to the PCB behind. Loosening does make a larger area go white.





EDIT: using a piece of plastic did not help.

[drhex]

Seems like one column driver is broken. Given it turns white on disconnect I'd assume that a high state on the line is off - you could try to find the right line on the connector and pull it up which should tell you which side of the cable it is.

[Bagel]

you could try to find the right line on the connector and pull it up which should tell you which side of the cable it is.

I don't know how to do that.


If I have checked and cleaned all connections. Maybe installing this PCB is worth a shot?

[james_s]

You could try, I doubt it will help, but with such a nice TV it's worth exhausting all other options before scrapping it. Have you looked on ebay for a used board?

[drhex]

OK, looking at the service manual and the amount of pins these aren't driving the columns directly. The actual drivers must be somewhere on the panel - you are out of luck probably. You can change the LCD control board if it doesn't cost a lot. Parts #s are here: https://www.manualslib.com/manual/961194/Sharp-Lc-70le740e.html?page=180#manual. Seems to me it should be DUNTKG031FM51 or DUNTKG031FM52. Manual says to replace the panel under these circumstances. Panel should be R1LK695D3GW80F.

[drhex]

Board you linked is for LC-70LE741E - most probably not compatible. You can obviously take the risk and try it, it is broken as is...

[Bagel]

 :scared:This is the board on this TV:

[Rasz]

changing boards with this defect is waste of money, Its bonding, in the glass itself, or driver on the ribbon.

[james_s]

The fact that it appears to be a dotted line made me think it was at least possible though not likely a problem somewhere else. I agree that it's probably something bonded to the panel, it's too bad you can't just saw the end off and make a nice 4:3 display.

[wraper]

Changing any boards is a complete waste of money. The fault is in LCD panel itself.

The fact that it appears to be a dotted line made me think it was at least possible though not likely a problem somewhere else. I agree that it's probably something bonded to the panel, it's too bad you can't just saw the end off and make a nice 4:3 display.

I don't get the reasoning behind your argument. A line means that a whole column is not working, and it's driven by IC in the panel. Also why do you mention it's dotted? Of course it is since it's a column of green subpixels.

[Bagel]

Here is what I plan on doing now:


I will apply heat (270-370°c) for 1-2s on the "1st" COF. If it does not work I will move on to the "2nd".

On each I will start in the middle and move outwards.

[Rasz]

I will apply heat

so exactly what I told you NOT to do, excellent!   
Pressing with a finger (after discharging yourself by touching something grounded) or for example credit card is all you need to detect if thats where the fault lies. Burning stuff up with zero practice of prior knowledge is how you destroy electronics.

btw this flex is also bonded to glass on the other end, fault might be there (unless its bonded internally between layers of the glass)

[Bagel]

I will apply heat

so exactly what I told you NOT to do, excellent!   
Pressing with a finger (after discharging yourself by touching something grounded) or for example credit card is all you need to detect if thats where the fault lies.

I'm sorry I forgot to mention that this approach did not work for me. What I am planning to do is risky, yes, however, I don't have any other idea by now and at this point I think it is worth a shot.

Appling pressure to the COF next to the green line did not work. Appling pressure the COF next to the other one did not work as well.

[Bagel]

According to what I have researched the POC ribbon can take 230°c long time exposure and 400°c short time exposure. So the heat will most likey be an issue for the surrounding components before it damages the ribbon itself. I will get some ribbons from an old and broken monitor so I can practice a bit.

[Bagel]

Ready for practice!

[Bagel]

Since I wasnt able to find my modern soldering station I have used this old timey heavy duty one:



Here I have three ribbons. The one at the bottom I have played around with quite a bit to get the feel for it. The middle I have applied 1-2s light touch in the middle as well as 2 points to the left and 2 points to the right. The top one is untouched. The deformation of the flex is due to me taping them onto epoxy:



Here I did apply 20s in the middle:



Here another 20s on the some COF:



Superficially they seem to be quite resilient. When I'll do this on the TV I will stick to 1-2s and a light touch. I will have a metronome running at 240bpm to ensure the timing is right.

[wraper]

 

[Bagel]

[Bagel]

The iron did not get hot enougg did it? 

[james_s]

If applying pressure doesn't work then applying heat is not going to work. Heat is a way of re-bonding a connection that has come loose, if pressing on it doesn't change anything then it is not loose.

[Bagel]

I now have tried with this one (no station directly into the powersocket) for 20s in the middel (5min heatup time):

[Bagel]

If applying pressure doesn't work then applying heat is not going to work. Heat is a way of re-bonding a connection that has come loose, if pressing on it doesn't change anything then it is not loose.

User "mon2" has recommended I open a thread in this forum:

https://www.badcaps.net/forum/showthread.php?t=101091&page=2

There a user claiming to have 13 years of LCD repairing experience believes that heat might still be a possible solution.

[Bagel]

Started with 230°C 1-2s on different points of the COF on the left and right flex next to the green line, went to 260°C, to 300°C, eventually to 370°C. The TV survived just fine the line however remained.

By playing around with the connection seen below, I can get a hole in the line. Disconnecting completly will turn the whole section white. Dont know if that is a useful clue. If there is nothing more to be done I will get rid of the TV.

[Bagel]

I hope I can gift the TV to someone local. On local listings people are asking quite some money for TVs that are more damaged than mine. Is there still any value in a TV like this?