LG 55UF850T - Horizontal lines

Aug 23, 2018
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Hi all,

Need a little help on troubleshooting and repair..I will start us off with a history....

Around 10 days ago whilst using TV the screen went half, and then fully blank from my PC HDMI input. The backlights still work, with audio but no image.

After trying various resets and such it was time to get it sent for repair. I suspected the TCON board to be at fault and LG service center agreed they could replace it for me for a reasonable price.

Fast forward a week and LG informed me the TCON is replaced however horizontal ines are appearing on screen. They have suggested the TV may need a new panel for about 500 dollars however couldn't be sure that would be the solution. Since that was never going to happen I bought a new TV and today collected the old one.

The TCON board has fixed part of the problem, going from no image to an image flickering with horizontal lines I can be certain the old TCON was defunct. The panel has never shown signs of fault until maybe now.

Now, being one to never give up and as I am not losing anything as a fairly handy individual I've decided to attempt repair without replacing the panel. Please note, at this point the unit will not be going back to LG and they admit to not being certain that it actually is the panel. Their technician just informed me that this is their procedure to replace rather than repair (for 500 bucks a time I'm not surprised!). I am also, with my limited knowledge, not sure the panel does need replacing.

I am now at the point of having back panel off the TV and ready to go. LG have had the front and TV chassis off to look at the LCD front and told me their may be some corrosion to the front board for the LCD panel. I think this is situated to the right hand side of the led power light and I would like to inspect, repair or replace any malfunctioned capacitors or ribbon cables before going much further.

Does anyone have any advice or other input as to what the issue may be or how I should start before I dive in.

Please, constructive and helpful feedback is warranted to establish a repair for the TV now. It will not be going back to LG and it will not be having a new panel....so what else can I try.

Best regards....

The Munky

UPDATE: Had the TV completely apart. Cleaned some ribbon cables etc. Anyway, main update is I ended up with around 200 red ants creating a nest between the main chassis and diffuser layer. Cleaned that out and reassembled but.no luck. Wondering what to try next. Any advice or places I can look for testing components. I'm thinking about ordering a new main board as it could be the video signal that is getting sent, or ordering could it be the power board is acting intermittently... we often have a lot of surges here. Any words of wisdom on it appreciated. Again, I don't mind have a muck around to try and figure it out.

I still find it odd that I get no signal on the old TCON but a signal and image with full screen horizontal lines on the new one. Wondering if ants may have done something like nibbling through a ribbon cable or similar.

Thanks

 
Solution
It's kinda frustrated in your part that you know the cause of the issue, tried to fix it but still not fixed, I'm really sorry to hear. :( Possibly that ants has something to do with the ribbon cable since you've mentioned that they made a nest there. Just a suggestion, for defective TV's especially if it's for hardware fix, don't go on repairing it if it cost too much than buying a new TV. Just buy a new TV.

paulchezter

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Aug 11, 2018
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It's kinda frustrated in your part that you know the cause of the issue, tried to fix it but still not fixed, I'm really sorry to hear. :( Possibly that ants has something to do with the ribbon cable since you've mentioned that they made a nest there. Just a suggestion, for defective TV's especially if it's for hardware fix, don't go on repairing it if it cost too much than buying a new TV. Just buy a new TV.
 
Solution