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LC-26DV24u White Screen - Sound Ok

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    LC-26DV24u White Screen - Sound Ok

    So I have a TV in my bedroom which I was given as a repair job due to a white screen issue. I suspected the T-Con board, but could never get it to replicate the issue after months of use. I gave it back thinking it must be something wrong with his input device, but he kept experiencing the issue so he gave it to me as a freebie. Its been sitting for months in the bedroom unused, until I got a chromecast today and figured I'd start being lazy and watch TV in bed.

    Of course, since I decided to use it for personal enjoyment, lo and behold, white screen. Sound works fine, this TV has a built in dvd player and I can hear it going, but all I get is a very bright white screen. Google being my friend I was directed to look into the mainboard to t-con ribbon cable (which I can't seem to re-seat for the life of me) and power supply transistor Q413 and fuse F404. I have attached the readings I get from both in an image, as well as the ribbon cable. It seems to me the voltage on the middle connection of the transistor (I believe is the collector) is far too high, as other posts I read on this issue show readings closer to 1.5V

    As an aside, when I was checking q413, I believe I shorted a connection somewhere and the TV started working again, until I move my meter probe off what it was touching, and it immediately cut back out. I have not however been able to replicate what I did which made the picture cut back in, as I was watching the screen, and did not see exactly what my probe was touching.

    I'm still a noob as all of my previous repairs have involved replacing bad caps, or entire main boards/power supply boards. So individual component level details I have no experience with. How does the voltage look, or any other suggestions?
    Attached Files

    #2
    Re: LC-26DV24u White Screen - Sound Ok

    That is the commonly failed transistor which supplies the Voltage to run the T-CON board.
    http://s807.photobucket.com/user/bud...?sort=3&page=1

    You can check for cold solder joints on all 3 legs of that transistor.
    Last edited by budm; 12-26-2014, 01:25 AM.
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment


      #3
      Re: LC-26DV24u White Screen - Sound Ok

      Well holy smokes, that seems like that was it. I checked the solder joints and didn't see anything that looked like a cold solder to me, but I sucked the solder away and flowed new solder in its place anyways, and now it's working.

      Thanks Budm!

      Comment


        #4
        Re: LC-26DV24u White Screen - Sound Ok

        Never mind, its back to white screen tonight.
        next idea?

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