AOC E970SW no backlight

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  • dick_barton
    Badcaps Legend
    • Aug 2015
    • 6642
    • Wales

    #21
    Re: AOC E970SW no backlight

    Those leds look as though they are identical in brighness.

    What is the full board number 715Gxxxxxx

    Can you post a good picture of this section of the power supply.
    Attached Files
    Last edited by dick_barton; 01-25-2021, 07:40 AM.
    Willing to help but I'm no expert.

    Comment

    • Sraros
      Badcaps Veteran
      • Jan 2017
      • 223
      • Greece

      #22
      Re: AOC E970SW no backlight

      715g6503-p04-001-001c
      Attached Files

      Comment

      • dick_barton
        Badcaps Legend
        • Aug 2015
        • 6642
        • Wales

        #23
        Re: AOC E970SW no backlight

        When all else fails and you have tested most of the components around U801 then the final alternative is to replace the IC.

        The manual I attached earlier is similar but not identical to your circuit.
        Willing to help but I'm no expert.

        Comment

        • Sraros
          Badcaps Veteran
          • Jan 2017
          • 223
          • Greece

          #24
          Re: AOC E970SW no backlight

          I replaced U801, with a new one... still nothing, the board reacts the same...

          Comment

          • dick_barton
            Badcaps Legend
            • Aug 2015
            • 6642
            • Wales

            #25
            Re: AOC E970SW no backlight

            That's a pity but it does now rule that out. Can you remove Q801 and test it this time out of circiut.

            Can you post a photo of the connector that is connected to the leds

            With the leds connected what is the voltage at each pin as you power up. Need to power up when testing each pin. The voltage may shoot up and just as quickly fall so if you have a min/max meter would catch it.
            Last edited by dick_barton; 01-26-2021, 10:42 AM.
            Willing to help but I'm no expert.

            Comment

            • Sraros
              Badcaps Veteran
              • Jan 2017
              • 223
              • Greece

              #26
              Re: AOC E970SW no backlight

              Dick, I scratched some points on the LED bar to check the leds 1 by 1
              In diode mode each one lights up.
              I reconnected the set to power and when I put my finger and make a short between some LEDs they slightly power up at some points
              Voltage is 0.2V between the 2 conmectors on the LED bar.
              The pins between the cables on the LED bar and the connector on the PCB make contact. Tested in diode mode
              Attached Files
              Last edited by Sraros; 01-26-2021, 12:59 PM.

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              • Sraros
                Badcaps Veteran
                • Jan 2017
                • 223
                • Greece

                #27
                Re: AOC E970SW no backlight

                Q801 out of PCB:
                D - S = 573 and reverse leads S - D = Infinity
                D - G = Infinity and reverse leads D - G = Infinity
                G - S = Infinity and reverse leads S -G = infinity

                Comment

                • dick_barton
                  Badcaps Legend
                  • Aug 2015
                  • 6642
                  • Wales

                  #28
                  Re: AOC E970SW no backlight

                  That definately appears to be good. The internal diode across the drain/source being the only reading.
                  Willing to help but I'm no expert.

                  Comment

                  • dick_barton
                    Badcaps Legend
                    • Aug 2015
                    • 6642
                    • Wales

                    #29
                    Re: AOC E970SW no backlight

                    I must admit I've never witness anything like what is shown in your last video.
                    It would be interesting to see what others think.
                    Willing to help but I'm no expert.

                    Comment

                    • Sraros
                      Badcaps Veteran
                      • Jan 2017
                      • 223
                      • Greece

                      #30
                      Re: AOC E970SW no backlight

                      I gave it up. It was fun to search around, but either way screen size was too small to do it sth

                      Comment

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