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2016-03-06

Samsung UE46D6200 - double image, ghost image - thin black horizontal line - panel defect

A friend sent me a picture of his Samsung and asked me if I could repair it. It suffered from double images in the upper half and a thin horizontal line on the lower third of the screen. He said that the line appeared first and the double images came later.

My first rule of TV repairs says: horizontal, irregular structures or single black lines are panel faults. They are caused by defects in the gate drivers, which are partially or fully shorted.

Knowing about the disastrous quality of the Samsung D series - I see a defect D with panel fault almost every week on eBay or eBay classifieds -  I had no doubt about it that this was yet another panel fault. I picked the TV up and took the opportunity for some investigation. Maybe it was a bonding problem and I could fix it with a hack.



The Samsung panel had no Y- (gate driver) boards and thus, no bonding on the left or right side to the panel. The only connection to the panel is made on the bottom of the screen, which drives both, the gate- and datalines.


The bonds and driver chips did not respond to any pressure or bending. They seemed ok. I also unplugged the two connectors to the TCON-board one after another to see if one side has the fault. Nope. The double image would not go away, regardless of what I did.

The problem with this type of panel are the gate drivers, which are inside the panel. On the glass, to be more specific. The semiconductors are sitting on the glass substrate. Absolutely no chance to repair.



So, this was a hopeless case. I removed all the boards, which had no fault, and dumped the rest. I also kept the nice thick plexiglass light guide sheet from the panel, this might come in handy some time.

My friend bought a nice Panasonic, which I recommended to him. I hope (and expect) that this one will last longer than the Samsung crap, which ran for ridiculous 3 1/2 years. Unless Panasonic bought panels from Samsung :-o

If you like to learn a lot about how LCD panels work, I recommend Ken Liew's ebook LCD/LED Screen Panel Repair Guide. It is a large, yet sometimes chaotic and hard to read - Asian English :-) - collection of tips and tricks on panel repair, written by an experienced practitioner. He spends some time explaining the cause of double images and suggests pretty wild hacks to revive the TVs, albeit with some loss in image quality.

The Asian repair guys generally tend to dig much more into the devices.

6 comments:

  1. This comment has been removed by the author.

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  2. Hi sir. I just want to make sure. is this as you explained above? is it LCD panel fault? https://www.youtube.com/watch?v=RnD5__S4j-Y

    Thanks in advance :)

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    1. Yes, it is a panel fault. The thin white line through the black box marks the edge of the sporadic noise.A gaga driver is faulty.

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  3. I meant gate driver... stupid autocorrect :-)

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  4. Hello,
    You mention horizontal lines may always be a panel fault. What about vertical lines or bands? I have a Philips with some vertical bands/line on the left side.

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    1. That's more difficult, because it is all in the details. If the lines are semi transparent and the image is visible under them, or if the image is ok besides them, it is the panel. If they are thick and solid color or black, maybe the TCON is to blame. Could be panel as well in that case.

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