Samsung UN75RU8000FXZA bad main board?

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  • Lee M.
    Member
    • Nov 2021
    • 35
    • United States

    #1

    Samsung UN75RU8000FXZA bad main board?

    When plugged in it will click and cycle the BL on and off, no pic and does not respond to remote. When I disconnect the cable from the PS board to the main board and then plug it in the BL will come on and stay on. There are only two boards in this set, the LVDS cables from the panel driver boards connect directly to the main board. Since the BL comes on and stays on I'm thinking the PS board is ok and the problem is on the main board. Should I order another main board or do I need to do more testing? thanks, Lee
  • Lee M.
    Member
    • Nov 2021
    • 35
    • United States

    #2
    Re: Samsung UN75RU8000FXZA bad main board?

    Update: When I unplug either or both of the LVDS cables from the main board the set will respond to the remote and turn on, the BL stays on, and I hear sound when I hit buttons on the remote like the home button. There is no pic. I'm guessing the tcon section on the main board is bad. If the tcon were good I would think I could get a pic on half the screen when I was unplugging the LVDS cables one at a time. What do you think?

    Comment

    • alfatv
      Badcaps Veteran
      • Sep 2020
      • 353
      • Canada

      #3
      Re: Samsung UN75RU8000FXZA bad main board?

      Most likely panel is bad

      Comment

      • Lee M.
        Member
        • Nov 2021
        • 35
        • United States

        #4
        Re: Samsung UN75RU8000FXZA bad main board?

        I thought each side of the panel was isolated from the other side? For example a tab bonding problem on the left side would leave the right side pic looking normal. I didn't know both right and left sides could just go blank at the same time and it be the panel. The only times I've seen the whole screen go blank like this it was due to a bad tcon. But I'm still learning.....lol

        Comment

        • Lee M.
          Member
          • Nov 2021
          • 35
          • United States

          #5
          Re: Samsung UN75RU8000FXZA bad main board?

          "Fixed" it with the tape method. Covered about 5-6 lines on the jumper ribbon cable between the two panel driver boards on the left side of the TV when looking at it from the back. Still have some faint horizontal lines in pic that show up mostly in the reds but not really noticeable from 10 ft or more away.

          Comment

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