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Sanyo Flat Shutting down

Discussion in 'Repairing Electronics' started by buddwisemonk, Oct 27, 2008.

  1. buddwisemonk

    buddwisemonk New Member

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    Hi, I have a Sanyo 26" Flat screen
    model DP26746
    The problem Im having is a bit odd. I got the TV from a friends mother who said it just didnt work.... vague I know. I took it home. Plugged it in and I got a picture for about 2 minutes, then it shut off. If you press the power button after that, you can hear a "click" like its trying to come on then another "click" like its cutting off but it never gives you a picture and the LED power light does come on. after a couple of tries it will no longer make any sound. If you wait 10 mins or so the process can be repeated. Anyone have any Ideas. I was thinking power supply or replacing the board on that side. But I have no Idea where to get the board from. Any fix advice or part supply info is greatly needed and appreciated. I dont want to spend a ton fixing this thing.
     
  2. flat5

    flat5 Member

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    Look for bad electrolytic capacitors in pulse power supplies.
     
  3. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Yes, high ESR capacitors are a VERY common cause of problems - if you're lucky, they might even be visibly bulging or leaking. Replace with 105 degree low ESR types.
     
  4. dave

    Dave New Member

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  5. buddwisemonk

    buddwisemonk New Member

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    Esr?

    Sounds like an easy fix. Sorry I am new to this but. what does an ESR look like and how do i tell which one is bad? I have a meter if that helps. Also will i need a soldering iron? Thanks for your help.
     
    Last edited: Oct 28, 2008
  6. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    ESR is "Effective Series Resistance", and you need an ESR meter to test it - or you can check for ripple using a scope - it's been the main cause of faults for many years now.

    But for a start look for bulging electrolytics.
     
  7. Mickster

    Mickster Well-Known Member

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  8. crutschow

    crutschow Well-Known Member Most Helpful Member

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    An electrolytic (generally in a relatively big tubular can which may have some writing on it like 470µF) may also be leaky as well as having a high ESR. Either way, they will often get hot so you might check for that after the TV's been on and quits operating. Unplug the TV before you poke around with your fingers.

    If you need to replace it, you will need a soldering iron and someone who's familar with soldering.
     
  9. buddwisemonk

    buddwisemonk New Member

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    I found two 105's that seem to be bulging at the top. I'm going to try to find a place to buy some today and replace them. Wish me luck. Thanks again guys and girls I really am grateful.
     
  10. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    105 will be the temperature rating, NOT the value - you need to check the capacitance and voltage required, ensure you get 105 degree ones (not 85 degree ones - which were more common), and preferably low ESR ones.
     
  11. buddwisemonk

    buddwisemonk New Member

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    It seems the only 820 uf 200v 105 C , I could find is in CA...hoping to find one at a local radio shack. anyone know of another place to get these? It seems these are rare...also is there another Value that will work Like 800 uf 200v 105C or is it a must replace with same kind of deal?
     
    Last edited: Oct 28, 2008
  12. crutschow

    crutschow Well-Known Member Most Helpful Member

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    800µF should be ok (although that's not a standard size) but you shouldn't go much smaller. Larger is also ok.
     
  13. buddwisemonk

    buddwisemonk New Member

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    so would a 1000uf 200V 105 work?
     
  14. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Yes, the tolerance on electrolytics is HUGE - often something like -25%/+50%.
     
  15. Mickster

    Mickster Well-Known Member

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    It would be advisable to change not only the bulging capacitors, but all those from the same manufacturer. There are some known names which are particularly likely to fail, from the perspective of technicians who regularly deal with them. (Please read the second post too):

    Badcaps Forums - List of Bad Cap Manufacturers

    HTH.
     
  16. buddwisemonk

    buddwisemonk New Member

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    now what? =(

    I just replaced the 2 bulging ESR with 820 uf 200v 105C and I still have the same problem. :( anymore ideas?
     
    Last edited: Nov 3, 2008
  17. flat5

    flat5 Member

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    Look for more bad caps.
    Sorry you are having trouble.
     
  18. crutschow

    crutschow Well-Known Member Most Helpful Member

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    Also a bad cap could have cause something else to blow, like a rectifier.

    Is there any possiblity of your getting a schematic for the TV?
     
  19. buddwisemonk

    buddwisemonk New Member

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    Thanks for the reply will see if I can find a schematic and locate the rectifier. One more question. When the TV is powering up ..what is the "click" i hear when it powers off.
     
    Last edited: Nov 4, 2008
  20. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    A relay, probably switching power to the mains PSU.
     
  21. buddwisemonk

    buddwisemonk New Member

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    I can't seem to find a schematic for the board and Im also having trouble even locating a picture of a rectifier...what should I be looking for. And how do I tell if its bad?
     

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