Any way to repair this??

Discussion in 'General Electronics Chat' started by Zlwebb, Jun 12, 2015.

  1. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
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    This is a buffer board from a Samsung led TV. The issue is a 4inch wide vertical section of the TV that has a bad image. It is cause by the broken connections. I have repaired traces before...but nothing that small. Any suggestions??[​IMG]
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,157
    3,064
    Buy a new one. Sorry, but that's all I could do if it was mine. You could use a good dissecting microscope to see the connections, but I can't imagine how to actually repair them.
     
  3. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
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    I was thinking about using heat to remove the ribbon. Then, using the aid of a magnifier I would use a circuitwriting pen to repair the damaged gold pads. Then toc seperate the pads I would use a needle to scratch away the excess circuit pen. At least that's all I can come up with because the goldfingers are way too small and close together to use a replating kit
     
  4. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    I've had marginal results (i.e. circa 40% success rate) with a 'hot air gun' and a rubber block (e.g. a 'sketch' eraser)

    The procedure:
    1) Gently heat the portion of the ribbon and PCB 'lands' corresponding to the delaminated connections to ~ 100 (Deg C)
    2) Apply firm pressure with the eraser block for at least 2 minutes.

    Following the above, if it lasts 1 hour it'll last indefinitely!:cool:

    Good luck!:)
    HP

    PS the described failure is often the result of (long term) high temperature operation -- thoughtful placement and maintenance of clean vent-slots will mitigate this...
     
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  5. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
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    What about repairing the damaged gold parts on the PCB? Or are you meaning to move the ribbon down to cover the damaged areas?
     
  6. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Generally the lands are not damaged -- it's simply a matter of delamination (that said they may appear damaged owing to contamination by adhesive, etc..) --- Note that the adhesive exhibits rather low surface tension when fused, hence the pressure will 'cleanly' force it out and allow re-connection --- I do not recommend you remove the entire ribbon lest you complicate matters with misalignment!

    Best regards
    HP:)
     
  7. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
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    I do think I will have to remove the entire ribbon. However there are alignment marks I can use for realignment. Do you think the circuitwriter pen could work? The lands are damaged. The area was damaged due to cleaner leaking into the area and causing corrosion. When Cleaning with isopropal alcohol the lands just disintegrated in some spots
     
  8. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Apparently the corrosive substance reacted with the base metal then the isopropanol dissolved the lands-to-PCB adhesive? OUCH!:eek:

    Although I have never attempted it I feel the 'circuitwriter approach' may be worth a 'shot' -- of course you'll need to implement measures preclusive of trace-to-trace shorts, etc... Alignment may be trickier than you think, however bioptic lenses (or even a decent 'mag lamp' ) may help that..

    Good luck! You'll need it!
    Best regards
    HP:)
     
    Last edited: Jun 12, 2015
  9. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    Your local auto parts store, may have what you need to repair this... the question is...how involved you want to get...
    The product, is conductive lacquer used to repair the old painted-on windshield heat strips... It is silver powder, in a suitable vehicle similar to acetone or lacquer thinner.
    I have used the stuff to repair broken elements in many automated 35mm Single-lens reflex film cameras. It shows promise for similar applications in Digital equipment as well...
    Your chore, will be locating a fine enough artists' brush to apply it to those fine connections... it can be done...

    In other equipment, I have repaired kapton flex-circuits as small as 3 traces per millimeter, and in some cases have custom-made flex-circuits with kapton tape, and magnet wire... Ya gotta do what ya gotta do...
    That's just me... I do that level of BS Just to keep dexterity up...
     
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  10. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
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    I'll have to look for that laqour. I have seen conductive paint but I'm afraid it will be too thick. Same with the pen. I'm thinking the best way is to cover all the lands with the conductive paint/ink then go back and scratch away the gaps to separate the circuits. I think that will be easier than trying to paint those tiny lines
     
  11. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Either that's one expensive TV or you've got a lot of time on your hands!?;);)

    Well hey! -- I salute your industry and determination!!!:D -- Once again - good luck!:)

    Best regards
    HP
     
  12. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
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    It was only 1200 2 years ago. It broke last year. I want to put it up in my basement. I can't let such a simple yet difficult problem make me go buy a new TV.
     
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  13. bwilliams60

    Active Member

    Nov 18, 2012
    725
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    Go to "ShopJimmy.com" and order a board. They are not that much to buy.
     
  14. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
    2
    The board is made into the led panal. They don't even sell one.
     
  15. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    I'll save you the frustration... The cover-all and cut slots method will not work... Once the conductive lacquer dries, it is relatively hard... any attempt to slot it, will only chip the entire deposit away... The lacquer, can be thinned with its primary solvent, such as acetone, or lacquer thinner in minute amounts,,,

    Get a tiny artist brush, an adequate magnifier... Take a shot of your favorite nerve potion, and good luck...
     
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  16. ian field

    Distinguished Member

    Oct 27, 2012
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    Replacing it outright would certainly be a lot cheaper than you originally paid, and you'll get something up to date with loads of new features.

    It might even work out cheaper than trying to repair that one - and still not winning at the end of it.

    Even if you can get the assembly to replace what's damaged, it won't be cheap - and the rest of the set will still be old, so something else could pack up just after you've spent loads on it.

    A couple of decades ago, the old one would have been a great donor for loads of interesting parts to experiment with.
     
  17. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
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    Well I would rather try to fix it since it is just one little issue causing the TV problem. I did buy a new TV when this broke with every feature you can think of. We are just wanting to put this downstairs and the TV has just been sitting there. Might as well give it a try. I'll post pics as I go along
     
  18. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
    2
    Question, is the ribbon attached by an adhesive that will reheat nicely? The entire ribbon is attached. So I need to heat it to remove it, and simply reheat it to reseat the ribbon?
     
  19. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    In my experience, yes...

    Because repair of the PCB will entail removal of adhesive residue from same, it will depend upon the amount of residue remaining on the ribbon itself --- It may be advisable to 'fortify' the bond via application of, for instance, low-temp "Hot Melt adhesive" 'around the edges' after the ribbon is aligned and in contact with the PCB -- Please, under no circumstances apply additional adhesive to the contact area!:eek::)

    Please note that, owing to its contraction upon re-polymerization and maintained elastic tension thereafter, acrylic 'Hot Melt adhesive' (e.g. Surebonder "Acrylstik") may be the best choice...

    Best regards and good luck!:)
    HP
     
  20. Zlwebb

    Thread Starter New Member

    Jun 12, 2015
    11
    2
    Thanks for the reply. I have never removed a ribbon like this before. Is there any adhesive underneath the ribbon? I wouldn't think there would be due to interfering with the connection
     
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