Sceptre 409BV-FHDU8HJ1L02 dead

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  • bigmatt0211
    Member
    • Dec 2015
    • 44
    • United States

    #21
    Re: Sceptre 409BV-FHDU8HJ1L02 dead

    Alright - the BLon when the tv is off is 2 mV, when I turn it on, the voltage is 3.39v

    The Adj voltage, when the screen is off, is 3 mV, when I turned it on, it jumped to 4.57V, but then dropped and stayed at 1.27V.

    Comment

    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA

      #22
      Re: Sceptre 409BV-FHDU8HJ1L02 dead

      Are you still getting only about 160VDC on the main cap? If you do, then the PFC Voltage booster is not working.
      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

      • bigmatt0211
        Member
        • Dec 2015
        • 44
        • United States

        #23
        Re: Sceptre 409BV-FHDU8HJ1L02 dead

        The main cap registered 160V off, 391V on

        Comment

        • bigmatt0211
          Member
          • Dec 2015
          • 44
          • United States

          #24
          Re: Sceptre 409BV-FHDU8HJ1L02 dead

          Does that still imply the PFC Voltage booster is not working?

          Comment

          • budm
            Badcaps Legend
            • Feb 2010
            • 40746
            • USA

            #25
            Re: Sceptre 409BV-FHDU8HJ1L02 dead

            Originally posted by bigmatt0211
            The main cap registered 160V off, 391V on
            PFC Voltage booster is working.
            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

            • bigmatt0211
              Member
              • Dec 2015
              • 44
              • United States

              #26
              Re: Sceptre 409BV-FHDU8HJ1L02 dead

              Well that's good news then.

              Alright, where else should I look to figure this out?

              Comment

              • CapLeaker
                Leaking Member
                • Dec 2014
                • 7992
                • Canada

                #27
                Re: Sceptre 409BV-FHDU8HJ1L02 dead

                Measure between pins VBL+ and VBL- on the connector where the LED backlights are connected. You may need to use the Min/Max feature on the DMM if you have this.
                I am thinking you got a bad LED in the backlights.

                Comment

                • budm
                  Badcaps Legend
                  • Feb 2010
                  • 40746
                  • USA

                  #28
                  Re: Sceptre 409BV-FHDU8HJ1L02 dead

                  Can we see the whole back side of the TV showing ALL the boards?
                  I believe the inverter board for the CCFL is INSIDE the panel.
                  Last edited by budm; 09-01-2016, 08:42 AM.
                  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

                  • CapLeaker
                    Leaking Member
                    • Dec 2014
                    • 7992
                    • Canada

                    #29
                    Re: Sceptre 409BV-FHDU8HJ1L02 dead

                    Oh! There I go... I had for some reason the impression that this was a LED TV!

                    Probably bad secondary on one of the inverter transformers.
                    Last edited by CapLeaker; 09-01-2016, 09:36 AM.

                    Comment

                    • bigmatt0211
                      Member
                      • Dec 2015
                      • 44
                      • United States

                      #30
                      Re: Sceptre 409BV-FHDU8HJ1L02 dead

                      Here is a picture of the whole back. The individual boards can be seen in one of the first posts, but if you'd like, I can take additional ones.

                      Between VBL +/-, there is 0V registered with me turning it on and off.
                      Attached Files

                      Comment

                      • CapLeaker
                        Leaking Member
                        • Dec 2014
                        • 7992
                        • Canada

                        #31
                        Re: Sceptre 409BV-FHDU8HJ1L02 dead

                        Well... you have to get at that inverter board on the left.

                        Comment

                        • bigmatt0211
                          Member
                          • Dec 2015
                          • 44
                          • United States

                          #32
                          Re: Sceptre 409BV-FHDU8HJ1L02 dead

                          So for this inverter transformer, is that something I can get to and successfully fix?

                          Comment

                          • bigmatt0211
                            Member
                            • Dec 2015
                            • 44
                            • United States

                            #33
                            Re: Sceptre 409BV-FHDU8HJ1L02 dead

                            Ah ok. working on it now, pics to come

                            Comment

                            • bigmatt0211
                              Member
                              • Dec 2015
                              • 44
                              • United States

                              #34
                              Re: Sceptre 409BV-FHDU8HJ1L02 dead

                              Here is that board on the inside
                              Attached Files

                              Comment

                              • CapLeaker
                                Leaking Member
                                • Dec 2014
                                • 7992
                                • Canada

                                #35
                                Re: Sceptre 409BV-FHDU8HJ1L02 dead

                                You can compare the secondary's on each transformer that they are within 3%. DMM in ohm setting.

                                Comment

                                • bigmatt0211
                                  Member
                                  • Dec 2015
                                  • 44
                                  • United States

                                  #36
                                  Re: Sceptre 409BV-FHDU8HJ1L02 dead

                                  I am not sure how to test for this. There are 4 connections on those transformers, which ones are the secondary?

                                  Comment

                                  • bigmatt0211
                                    Member
                                    • Dec 2015
                                    • 44
                                    • United States

                                    #37
                                    Re: Sceptre 409BV-FHDU8HJ1L02 dead

                                    It seems pins 1 and 3 are connected, but I can't find what 2 and 4 connect to.

                                    Comment

                                    • vinceroger69
                                      Badcaps Legend
                                      • Mar 2012
                                      • 6714
                                      • uk

                                      #38
                                      Re: Sceptre 409BV-FHDU8HJ1L02 dead

                                      is there any numbers on the transformers we maybe able to get a pinout etc

                                      Comment

                                      • bigmatt0211
                                        Member
                                        • Dec 2015
                                        • 44
                                        • United States

                                        #39
                                        Re: Sceptre 409BV-FHDU8HJ1L02 dead

                                        There are some numbers/letters:
                                        t51.8292.291
                                        b2f 1235
                                        00 4 C A 5

                                        Comment

                                        • CapLeaker
                                          Leaking Member
                                          • Dec 2014
                                          • 7992
                                          • Canada

                                          #40
                                          Re: Sceptre 409BV-FHDU8HJ1L02 dead

                                          a new inverter board is $14. You gonna need one anyway if one of these transformers is bad.

                                          Comment

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