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lg 47LC7DF

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    lg 47LC7DF

    So my neighbor comes to me toting this massive 48" TV. I help him into the house and we set the behemoth on the floor.

    He proceeds to tell me it wont turn on and that his son who "works on computers" looked at it and couldnt find the problem.

    Being someone who works on computers professionally, model railroads in O scale, and does electronics work for fun, I dig into the tv.

    First things checked was the cord, the wires going to the power board and then the fuses. The primary line fuse (8A) was solid, while the 5A going to the inversion circuit was reading open. Replaced the 5A fuse with a slow-blow glass so that I could witness the carnage. I put on my safety glasses and energize the circuitry.

    For about a second, I hear the brief hum of a transformer and then its quiet. I look at the secondary fuse and it had warped from blowing.

    The board is: EAY36781301

    The caps on this board look quite stellar, but the heat shield has discolored dramatically.

    Click for pictures (External Site)

    #2
    Re: lg 47LC7DF

    I've done some more looking and the fuse goes to the longest heat sink bar. There are 4 small transistors and 2 larger ones, but the information for them seems obliterated and I cannot get a decent picture of them.

    I am hesitant to replace the caps if there's really no need to do it as the two very large 450v caps are 5$ each.

    Again, the fuse is instantly blowing the moment power is applied. Fuse #2 confirmed a potential short with quite a stellar pop and burst of light.

    Comment


      #3
      Re: lg 47LC7DF

      Replace fuse with a 200w lightbulb.
      this way you can replace any suspect parts and won't risk damaging any new parts you install, also save you blowing any more fuses.

      Comment


        #4
        Re: lg 47LC7DF

        Interesting. I've never tried that before. What voltage do you suggest on the lamp? 110 or 208/210? Only thing I know of in excess of 200w is a halogen.

        Also I found a kit offered by Coppell TV Repair which includes the two large transistors I had mentioned and a few other bits for 15$.

        Comment


          #5
          Re: lg 47LC7DF

          On the positive upside, the repair kit I purchased stopped the fuse blowing issue. It took a long time to get here, but it wasnt all that bad to install.

          Unfortunately, I am sorry to report that the tv still does not power on. Still no standby power, so I am considering replacing caps.

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