Sharp LC-60E79U Backlight Flicker

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  • SolderMaster
    Senior Member
    • Dec 2013
    • 53
    • USA
    #1

    Sharp LC-60E79U Backlight Flicker

    Hiya folks.

    This one has a backlight flicker problem as the title states. Eventually the set will shut itself down into protect mode.

    Right now I have it in my basement running Youtube videos off an Xbox 360 for a source. Gonna let it run over night to see if I can get it to crash.

    It seems to flicker mainly on the right side of the screen. Tapping on the metal top piece of the inverter board seems to make it stop for a few seconds before the flicker starts back up.

    The main model number of this set is LC-60E77UN. https://www.manualslib.com/manual/91...page=65#manual

    I'll check in tomorrow and let ya'll know what happened.
    Tags: None
    • CapLeaker
      Leaking Member
      • Dec 2014
      • 8107
      • Canada
      #2
      Re: Sharp LC-60E79U Backlight Flicker

      cold solder joint, or bad transformer.

        Comment

        • SolderMaster
          Senior Member
          • Dec 2013
          • 53
          • USA
          #3
          Re: Sharp LC-60E79U Backlight Flicker

          Error code is DET_15V (34pin) error (L). UR13V is not applied.
          If error is detected during operation, error standby is activated by
          polling. ( Pwr flashes x2, OPC flashes once )

          On the power supply or the inverter, CapLeaker?

          Voltages on Power Supply going to Main:

          PNL_POW = 3.26
          BU5V = 5.00
          PS_ON = 2.8
          AC_DET = 3.0

          S14.3V = 14.39
          UR14.3V = 14.39

          PNL12V = 11.97
          PNL12V = 11.95

          Both red wired cables have 24V where it should

          All voltages recorded white TV is on and flickering.
          Attached Files
          Last edited by SolderMaster; 01-03-2019, 05:05 PM.

            Comment

            • CapLeaker
              Leaking Member
              • Dec 2014
              • 8107
              • Canada
              #4
              Re: Sharp LC-60E79U Backlight Flicker

              Look at the solder joints on everything on the HV side on the inverter board. Also check these blue litte HV caps at the CCFL plug. Compare the HV output (secondary) on each transformer with your DMM on Ohm scale and note it down. If one transformer is more than 3% off, that's the bad one. The bad transformer will also run hotter than the others. Hope that helps you to get started.

                Comment

                • SolderMaster
                  Senior Member
                  • Dec 2013
                  • 53
                  • USA
                  #5
                  Re: Sharp LC-60E79U Backlight Flicker

                  I took the slave M2 board out, smaller one with 3 transformers on it, and measured Ohms from Hot to DC, the only one that reads any different is T1601. Lower at 1550 Ohms vs 1580 like the rest of them. Also, there is a "cooked" look to the connector going into the CCFL connector. The back side of the CCFL looks "cooked" as well.

                  Can that be replaced along with the board and/or transformer? I do have experience replacing LED strips on LED Tvs so I'm not afraid to tear the whole thing down.

                  What little blue caps?

                  Set now flashes "Lamp Error" 1 blink of the Power light.
                  Attached Files
                  Last edited by SolderMaster; 01-03-2019, 07:07 PM. Reason: Forgot stuff, new error code

                    Comment

                    • nomoresonys
                      Badcaps Legend
                      • Jan 2013
                      • 12100
                      • U.S.
                      #6
                      Re: Sharp LC-60E79U Backlight Flicker

                      Testing transformers, couldn't find one on sharp, you said you have lamp error. If you have a bad lamp it should show up on transformer test. https://www.youtube.com/watch?v=oE6K4xBVweA

                        Comment

                        • SolderMaster
                          Senior Member
                          • Dec 2013
                          • 53
                          • USA
                          #7
                          Re: Sharp LC-60E79U Backlight Flicker

                          This set is now stuck in the lamp error mode. I can force it on, backlight comes on for a split second then turns off, then tv shuts down flashing lamp error. I was able to get into service mode and using a flashlight, navigated to the lamp error reset and turned it on. Powered down set, and restarted. Tv came on for a second then shut down again with lamp error.

                          Has anyone here upgraded to LEDs in one of these sets? Or should I scrap this thing and move on?

                            Comment

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