TCL 55S403 No picture. Sound and Backlight OK.

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  • Jeryswan
    Member
    • Mar 2020
    • 39
    • USA

    #1

    TCL 55S403 No picture. Sound and Backlight OK.

    To start, my electronics repair shop is pretty new to the TV repair game so forgive me asking noob questions. Plus I am fairly new to this forum so if this has already been answered, I may need some help using the search function more efficiently.


    I have a 55" 55S403 that turns on, produces sound and backlight but no picture. Tested voltages on the T-con and mainboard and voltage is present. Honestly, don't exactly know what voltages to look for but we know it at least has voltage present. No panel ribbons are torn. Reseated all connections between boards.

    It sounds like it might be in need of a T-CON replacement..... However, we are new and don't really know what we are doing.

    Yes, we are Youtube university specialists. Specialist is used VERY loosely. lol

    On a separate note, I would LOVE to send my tech to get some TV repair training. Anyone know anywhere good?
  • neilc6
    Badcaps Legend
    • Nov 2015
    • 1550
    • Canada

    #2
    Re: TCL 55S403 No picture. Sound and Backlight OK.

    With a TV turning on with backlight and no video, the first suspect is the tcon board. Some newer models don't have tcons. To make sure it's not the panel, power up the TV with only one ribbon between the tcon and panel connected at a time to see if one side displays a picture. If one side is good, it's a bad panel and not the tcon.

    Comment

    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA

      #3
      Re: TCL 55S403 No picture. Sound and Backlight OK.

      Show us good clear pictures (using 'Go Advanced' to attach the pictures) of the whole backside of the TV showing all the boards so we can see what we are dealing with.
      Last edited by budm; 09-23-2020, 09:54 PM.
      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

      • Jeryswan
        Member
        • Mar 2020
        • 39
        • USA

        #4
        Re: TCL 55S403 No picture. Sound and Backlight OK.

        Here's some pictures of the back of the TV and all the boards. After we unplugged one side of the tcon, this is what the tv looked like. it was mirrored for when we tried the same thing with the other side.
        Attached Files

        Comment

        • Jeryswan
          Member
          • Mar 2020
          • 39
          • USA

          #5
          Re: TCL 55S403 No picture. Sound and Backlight OK.

          Originally posted by budm
          Show us good clear pictures (using 'Go Advanced' to attach the pictures) of the whole backside of the TV showing all the boards so we can see what we are dealing with.
          Check out the pictures above.

          Comment

          • Jeryswan
            Member
            • Mar 2020
            • 39
            • USA

            #6
            Re: TCL 55S403 No picture. Sound and Backlight OK.

            Originally posted by neilc6
            With a TV turning on with backlight and no video, the first suspect is the tcon board. Some newer models don't have tcons. To make sure it's not the panel, power up the TV with only one ribbon between the tcon and panel connected at a time to see if one side displays a picture. If one side is good, it's a bad panel and not the tcon.
            Checked both sides by unplugging panel to tcon ribbon on left side only then on right side only. Neither side displayed an actual picture. Just black with one side white and vise versa for the other side. I posted a picture above with what it looks like.

            Comment

            • budwich
              Badcaps Legend
              • Jul 2015
              • 3097
              • Canada

              #7
              Re: TCL 55S403 No picture. Sound and Backlight OK.

              your panel has a problem in the top right corner of the panel... the black "corner". Not sure if you can do anything about it on a TCL set as they are somewhat different than others because of a "roku based" operating system.

              Comment

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