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Equipment Repairs => LCD TV forum => Topic started by: HateTV on January 03, 2019,07:57:10
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Hello to All,
first of all sorry for my bad english. ;)
I have a UE46D7090 with vertical lines visible in menu and all Sources. It started 1year ago with 2 or 3 lines. Now there are many lines. I was not sure if T-Con , Signal Board or maybe Display or Connectors are involved. Till here everything looks clear, lines were all in the same place and no change of it........till this hot Summer. I returned from Holly-day and room was between 28° and 32°. And when i turned on TV the lines were gone. There was non of them, not a few.....no absolutely no lines. That was the point were i guessed that the Display should not be defect. Few Days later the weather changed, room-temperature falls down.........oh how funny i have my vertical lines back. I have tried to reproduce this with Hair-dryer with mounted backplate and with dismounted backplate. I was not able to reproduce it. My guessing was some weak lid contact of one of the BGAs. But i`m Stepping in the dark. Maybe someone could bring a bit light in the dark. I have taken some photo of the problem, see attachment.
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Sure looks like a crook display panel to me, but you could try cleaning and reseating the flat cable connector that goes from the main board to the T-con (both ends) and likewise with the cables between the T-con and the panel. Bruce
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Hi downunder,
thx for your time. The cable Connector between Main Board and T-con i have checked. (useless) I just get no idea why the panel should work perfect on higher temps....when it is crook.
Cables between T-con and Panel i will try next.
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Also check the address boards, the two narrow strips at the very bottom of the panel that feed picture data to the panel. There may be some traces of corrosion from cleaning fluid entering from the viewing side of the panel or an infestation of ants - they just love it down there and the formic acid they produce doesn't go too well with copper tracks. Bruce
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Hi downunder,
before your last post i have opened TV again. 1th i have cleaned both ends of the cable between Main Board and T-con and mounted them again. 2th i removed everything that keep me away from removing the two Cables that are connection between T-Con and panel. 3th i opened the two connectors and cleaned cabels and connectors. At that point i had no idea of how the other sides of these cables are connected to the panel. It was not visible to me. So i tryed to lift the metalstripe that is taped to the bottonside of the panel. But one of the tiny silver (shity) screws (that mount this metalstripe to the back) get damaged. So i was not able to verifiy how these Cables are mounted to the Panel....i have mentioned some thin kind of circuit board but couldn`t see more than that.
So maybe you could discribe in easy words how this cables are mounted to the panel and if there is another contact area that could be cleand and how it could be cleaned. Ants......no ants in here, lol. ;) But cleaning fluid maybe. And before i forget, i had some nice SFX, after my cleaning. When tested TV, allmost everything that is normaly black was green. You should have seen my face after that. :( I was just 10s away from opening the window. But when i pushed a bit to the connector (cable between main and T-con, T-con side) the green was gone and all colores were ok. First my hope was that this cable or the connector is part of my mainproblem but after remounting and few trys of soft pulling against the connector the lines should be more or less or on other places (i guess) But nothing changes so i guess my hope was just a hope.
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If your picture has got worse, then you can't have fitted the flat cables correctly. Maybe at a slight angle or not centrally or far enough into the socket or you've damaged the metal traces on the cable ends. You did of course lift the latch on the socket to release the cable? A squirt of cleaning fluid into the sockets would help. Refit the cables then close the latches.
The address boards under the metal strip have 2 input sockets for the 2 flat cables from the T-con. The cables are detachable here, so clean them. Beyond that
are more flat leads that feed the data into the panel, but these are glued to the panel by a special process or embedded into the glass panel, so these are not
serviceable. If the glue process is used, it is possible that one or more of the contact points has lifted away and no longer makes contact . Bruce
.
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Hi downunder,
nah, cable was fitted correctly (till click on both sides), and no. Only the Connectors between T-con and Adress Board had latches on the connector (T-con side, othe till now not visible) and yes this i have pulled to open and pushed to close (to many Cellphone and Nintendo repairs to forget the Latch. I have a daughter. ;) Cable between Mainboard and T-con produces the green, and here the Cable had the fixing mechanism. So there is normaly nothing you can do wrong. I guess my Socket ( T-Con side) has more backlash as usual. It was fixed correctly. I did not push the cable in connector direction to get rid of the green, i just pushed slightly on top of the connector. ( T-con side).
Ok i understand the metal strip must be removed, to make the last check to the connections of the adressboard. So i must use a screw extractor to kill the damged screw. Cause screw is to small for my extractors i will buy a smaller on and will report if its done.
thx