Sony KD-55X8509C – No Backlight

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  • birchy7
    Member
    • Mar 2018
    • 25
    • United Kingdom

    #1

    Sony KD-55X8509C – No Backlight

    Hi, I have taken this TV on against my better judgement,
    It was left in for repair at our local repair shop with the following history.
    Tv powers on, s/by led flashes green & amber for approx 30secs then goes to a solid white.
    You can stop the green/amber flashing earlier if you turn tv on with remote or side power button, this brings you straight to a solid white lit led,
    Nothing appears on screen, no backlight lit or no image shows when shining torch at screen, there is some audio when I select menu, source etc on remote control, so I guess tv has powered on.
    The chap said he replaced the main board (B), then carried out a USB update, this resulted in the TV now just remaining powerless with the s/by led blinking with 1 red light every 30secs, the optical audio socket is not lit on the main board as it was before.
    He gave up on the TV and now I have it in front of me, I was able to get a working replacement main board & have fitted it, the results I now get is the exact same as we had before it went into the repair shop, still no backlight or no dark image.
    Quick checks on voltages on power supply show all is well methinks, the voltage to the LED strips sits at 64volts on connection CN6801, I expect this should be much higher?
    I have no service sheet for this so any helps would be much appreciated.
    Attached Files
  • birchy7
    Member
    • Mar 2018
    • 25
    • United Kingdom

    #2
    Re: Sony KD-55X8509C – No Backlight

    hi, had another quick look at this tv on my lunch,
    I tried doing the power/v- reset,
    I held the 2 buttons in & powered on with plug,
    All i get is the green/amber flashing for approx 30secs, then light goes out, no green led.

    I will take all voltages and post them here later this evening.
    cheers

    I have not done a usb update yet incase it bricks the main board as with what happened in the repair shop.
    Last edited by birchy7; 09-04-2019, 05:29 AM.

    Comment

    • nomoresonys
      Badcaps Legend
      • Jan 2013
      • 12114
      • U.S.

      #3
      Re: Sony KD-55X8509C – No Backlight

      Green/amber usually indicates a software problem, I would check and see if there was any problems reported with the current one availabe at sony UK, if not try an install, a firmware update is always recommended after a mainboard replacement.
      Last edited by nomoresonys; 09-04-2019, 07:35 AM.

      Comment

      • birchy7
        Member
        • Mar 2018
        • 25
        • United Kingdom

        #4
        Re: Sony KD-55X8509C – No Backlight

        hi, i've been tempted with doing the usb update, just kinda put of after the repair shop seemed to have bricked the orginal main board with update,
        I contacted the repair guy & compared the update file, his & the 1 on sonys website are the same...
        shall i go forth & do the update.....lol

        Comment

        • nomoresonys
          Badcaps Legend
          • Jan 2013
          • 12114
          • U.S.

          #5
          Re: Sony KD-55X8509C – No Backlight

          Damn good question, I would check real thoroughly to make sure that update isn't buggy, wonder how long it has been out. Possibly buggy firmware is why I never set my tvs to auto update.
          Last edited by nomoresonys; 09-04-2019, 08:06 AM.

          Comment

          • nomoresonys
            Badcaps Legend
            • Jan 2013
            • 12114
            • U.S.

            #6
            Re: Sony KD-55X8509C – No Backlight

            I did run across this, not sure if it pertains to your tv but it does have to do with Android tvs: https://www.forbes.com/sites/johnarc.../#50c2c08b4741

            Comment

            • birchy7
              Member
              • Mar 2018
              • 25
              • United Kingdom

              #7
              Re: Sony KD-55X8509C – No Backlight

              cheers for that, intrestinging read, i could live with this tv here giving out a loud beep now and again..lol beats what i'm getting from it now haha

              Comment

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