Sanyo DP40142 No backlight

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  • Shane711
    Badcaps Veteran
    • Dec 2014
    • 493
    • USA

    #61
    Re: Sanyo DP40142 No backlight

    Only if I buy them NEW, is it usually marked on the LEDs that come out of the TVs because I got enough to fill a bin.

    Comment

    • Shane711
      Badcaps Veteran
      • Dec 2014
      • 493
      • USA

      #62
      Re: Sanyo DP40142 No backlight

      I do not see any markings on these used LEDs so unless there is a way I can test them I might have to buy new.

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA

        #63
        Re: Sanyo DP40142 No backlight

        OK, that is why you do not have the spec sheet. One way to find out is to look up the spec sheet of the LCD panel, it will show the VF and the current requirement for the LED backlights section.
        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

        • Shane711
          Badcaps Veteran
          • Dec 2014
          • 493
          • USA

          #64
          Re: Sanyo DP40142 No backlight

          So then from that data I use a higher amperage LED? like maybe an extra 200ma?

          Comment

          • budm
            Badcaps Legend
            • Feb 2010
            • 40746
            • USA

            #65
            Re: Sanyo DP40142 No backlight

            The LED I use for replacement has current rating of around 400mA, that is why you should find out how much current the circuit is pumping in to the LED to give us some clue as to what is going on.
            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

            • CuriousJohn
              Ordained
              • Dec 2018
              • 134
              • Great Britain

              #66
              Re: Sanyo DP40142 No backlight

              Originally posted by kasfamily
              Hi Herbssat. Need photo marking Q005. Here's what I found on this driver, it is not my
              Appreciate this as spent yday afternoon replacing 7 blown led's on one of these sets only to find it still no go, little bit Grrrr

              Comment

              • xanscam
                New Member
                • May 2021
                • 3
                • mexico

                #67
                Re: Sanyo DP40142 No backlight

                Originally posted by Herbssat
                Hi gurus. I have this Sanyo set at the moment with no backlight at all. All the voltages have been checked at P802 and P803 and are within spec. 24v is going to the inverter and the voltage for bl on is 3.2v as well as the pwm voltage of 2.5v. The panel for this tv is the LTA400HM23. I could not find a detailed datasheet but i did see that the led driver for this panel is embedded. Maybe some of you guys can shed some light on this set. Your help is appreciated.
                Hola amigo, pudiste resolver la falla de tu TV DP40142

                Comment

                • xanscam
                  New Member
                  • May 2021
                  • 3
                  • mexico

                  #68
                  Re: Sanyo DP40142 No backlight

                  Originally posted by Herbssat
                  Here is an update on this set. Replaced R053 whose value had increased to 1kohm. It was supposed to be 85ohms. Capacitor c032 was also bad next to it. Since i could not find the backlight strip that i needed anywhere i resorted to jumping the strip with a piece of 24gauge solid bus wire. It was also recommended in a russian forum that the contacts on the backlight strip be soldered to each other because of poor connections. I havent done that yet. I appreciate all the info and help that i got from kasfamily. This was a dog. No panel parts to be located except in russia. This set was designed to fail. Now i must clean the panel parts and put the tv back together. I ran it for about 9 hours straight. A picture of the working repair is attached.
                  : compy:: compy:

                  What components did you change?

                  Comment

                  • xanscam
                    New Member
                    • May 2021
                    • 3
                    • mexico

                    #69
                    Re: Sanyo DP40142 No backlight

                    Originally posted by Hartman
                    R053 is not 85 ohms but the smd code is 05B which is 1k1 ohm (1100 ohms)
                    I just repaired my Philips 40pfl3208 which uses the same panel.
                    In my case no backlight and R053 was 7kohm instead of 1k1
                    I also saw that the connecors between the ledstrips made very poor contact.
                    You will have to bypass all of these in order to repair it, so that it is reliable.
                    The led driver passes its power onto a green strip, that transfer it to the horizontal positioned led strips.
                    I also bypassed these connectors in order to make it reliable.
                    Greetings
                    Jeroen Hartman
                    Cctv technician
                    Netherlands
                    GOOD MORNING FRIEND, WHAT YOU REPLACED IN YOUR LED DRIVER :llanto:

                    Comment

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