Samsung PN58C550G1FXZA won't turn on

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  • micro1966
    New Member
    • Apr 2014
    • 4
    • USA

    #1

    Samsung PN58C550G1FXZA won't turn on

    I've tried to follow Tom's troubleshooting, but I'm not sure I've got it right.

    Worked fine then one day just wouldn't come on. Red (power) light flickers or blinks once. If you keep pressing buttons, it eventually goes out. I've not timed it to see if it'll do it by itself, but I don't think it will (I recall leaving the room and coming back later, having forgotten to unplug it, and the light was still on).

    First fuse on the power board (lower left) has 126.5 v (roughly) on both sides. Second fuse (just to the right of the first one) has near zero. I verified the two fuses were the same, 10A 250V, (opaque type, so you can't see the element--who thought that was a good idea?), then I swapped them. Same result: first fuse has voltage, second does not.

    Vs tested at the test point, as well as on pins 1 and 2 of the outbound connector to the Y board while that was disconnected; also tested on pins 1 and 2 of the outbound connector to the X board while disconnected. It shows cycling voltage, never above about 12 v. Typical (but randomly varies) sequence is 9.3, 5.8, OL, 10.2, 4.3, OL, 11.3, 4.6, OL (a three, sometimes four, number sequence, ending in OL, takes about 3 seconds). It goes through that for about 30 seconds, and then decays to zero (0.02).

    When turned on, you can hear the relay, then a few seconds later a softer click. I don't see any change in measurements due to the second click, though.

    Obviously, disconnecting Y or X individually didn't make a difference.

    I can't tell you about sound because it is set up to get sound from an amp, so the internal speakers are turned off (any way to force them on without seeing the screen?).

    Tom's troubleshooting says to check for shorts, but I can't figure out where/how to do that. Any help/guidance would be appreciated.

    Any other thoughts before I randomly replace the power board? I'm probably not ready to get down to the component level, although I could be persuaded. So, board level diagnosis would be sufficient for me. It's just my preference to have a good idea that it's that board before I get one.

    It's my understanding that, if nothing changes with Y disconnected or with X disconnected, and voltage comes in but doesn't go out of the power board, then the fault is there. Or can the main board or logic board control that?

    A green light on the logic board comes on and goes out in about three seconds after turn on, if that helps at all.

    Thanks for any help provided.
  • micro1966
    New Member
    • Apr 2014
    • 4
    • USA

    #2
    Re: Samsung PN58C550G1FXZA won't turn on

    Any thoughts from anyone?

    Comment

    • AWTVs
      Member
      • Jun 2014
      • 27
      • US

      #3
      Re: Samsung PN58C550G1FXZA won't turn on

      Did you ever find your issue?

      Comment

      • micro1966
        New Member
        • Apr 2014
        • 4
        • USA

        #4
        Re: Samsung PN58C550G1FXZA won't turn on

        Yes. The power board fixed it. In almost 7 months, I got no responses at all on this forum. Very disappointing.

        Comment

        • AWTVs
          Member
          • Jun 2014
          • 27
          • US

          #5
          Re: Samsung PN58C550G1FXZA won't turn on

          I noticed that. I was quite surprised of those results or lack of them as I have been helped by responses numerous times. Anyways, I appreciate your response and think that is where I will start my repair. Thanks.

          Comment

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