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    #41
    Re: higher standby voltage on a phillips tv power supply

    the transforner is T501

    Comment


      #42
      Re: higher standby voltage on a phillips tv power supply

      Originally posted by DjKrish View Post
      Ok now theres picture on the screen. But the backlight transformer started buzzing lightly when picture is there. Below are the readings from left.

      Silver - 5.50v
      Black - 69.6v
      Silver - 69.6v
      White - 133.7v
      Silver - 5.66v
      Blue - 69.7v
      Silver - 69.7v
      Red - 134v
      Please put the pin name on each pin of that LED connector, your picture is not showing the pin names.
      Last edited by budm; 08-08-2020, 11:38 PM.
      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


        #43
        Re: higher standby voltage on a phillips tv power supply

        Originally posted by DjKrish View Post
        Not really sure. The tv came like that. There's no heat though. Now the tv had good picture and sound. Except the buzzing sound from the back light transformer.
        Some one worked on that wire.
        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


          #44
          Re: higher standby voltage on a phillips tv power supply

          Originally posted by budm View Post
          Please put the pin name on each pin of that LED connector, your picture is not showing the pin names.
          LED 4K - Silver - 5.50v
          LED 4A - Black - 69.6v
          LED LED3K - Silver - 69.6v
          LED 3A - White - 133.7v
          LED 2K - Silver - 5.66v
          LED 2A - Blue - 69.7v
          LED 1K - Silver - 69.7v
          LED 1A - Red - 134v

          Comment


            #45
            Re: higher standby voltage on a phillips tv power supply

            Originally posted by DjKrish View Post
            the transforner is T501
            T501 is the power transfomer that supplies 12V, 24V, and VLED power supply that feed the two LED boost converter power supplies to drive the LED strings.
            So disconnect the LED connector and see if the buzzing stops.
            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


              #46
              Re: higher standby voltage on a phillips tv power supply

              Originally posted by budm View Post
              T501 is the power transfomer that supplies 12V, 24V, and VLED power supply that feed the two LED boost converter power supplies to drive the LED strings.
              So disconnect the LED connector and see if the buzzing stops.
              when the tv is only on no signal mode, buzzing is lower, but if i put a picture or movie on, it becomes louder. I disconnected the backlight cable, no buzzing sound. I can see still image on the screen if i put a torchlight.
              Last edited by DjKrish; 08-09-2020, 12:06 AM.

              Comment


                #47
                Re: higher standby voltage on a phillips tv power supply

                Originally posted by DjKrish View Post
                when the tv is only on no signal mode, buzzing is lower, but if i put a picture or movie on, it becomes louder. I disconnected the backlight cable, no buzzing sound.
                Put the LED connector back in place, then lower the Backlights level (not brightness) to about 30% to see if the buzz gets lower.
                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


                  #48
                  Re: higher standby voltage on a phillips tv power supply

                  Originally posted by budm View Post
                  Put the LED connector back in place, then lower the Backlights level (not brightness) to about 30% to see if the buzz gets lower.
                  Ok the thing is, this tv doesnt have a backlight adjustment, it only has 3 modes, standard, power, best picture. So i assumed best picture is high and i selected it, buzzing a bit louder, then i put standard or power mode, buzzing goes lower. Then i started playing with contrast, when goes to 30% it buzz louder, goes to 50% not loud, below 30% louder. When playing a video, buzzing is lower. I think the buzzing gets louder when image becomes more brighter

                  Comment


                    #49
                    Re: higher standby voltage on a phillips tv power supply

                    So what u think? The driver circuit? Already tested all the caps around. All of them are ok.

                    Comment


                      #50
                      Re: higher standby voltage on a phillips tv power supply

                      Originally posted by DjKrish View Post
                      Ok the thing is, this tv doesnt have a backlight adjustment, it only has 3 modes, standard, power, best picture. So i assumed best picture is high and i selected it, buzzing a bit louder, then i put standard or power mode, buzzing goes lower. Then i started playing with contrast, when goes to 30% it buzz louder, goes to 50% not loud, below 30% louder. When playing a video, buzzing is lower. I think the buzzing gets louder when image becomes more brighter
                      Contrast is for Video adjustment, it does not affect backlights level or backlight circuit.
                      Are you sure the buzz is not coming from speakers?

                      Try adjusting brightness, this TV may be using brightness for the backlights level adjustment.
                      Also try turning off 'DYNAMIC BACKLIGTS' mode, see page 36 of user manual: https://cdn.badcaps-static.com/pdfs/...45d25a9b6a.pdf
                      Last edited by budm; 08-09-2020, 01:13 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


                        #51
                        Re: higher standby voltage on a phillips tv power supply

                        Originally posted by budm View Post
                        Contrast is for Video adjustment, it does not affect backlights level or backlight circuit.
                        Are you sure the buzz is not coming from speakers?

                        Try adjusting brightness, this TV may be using brightness for the backlights level adjustment.
                        Also try turning off 'DYNAMIC BACKLIGTS' mode, see page 36 of user manual: https://cdn.badcaps-static.com/pdfs/...45d25a9b6a.pdf
                        Speaker is down to zero. Dynamic contrast is off. Dynamic backlight is off. Now the buzzing sound gone way lower.

                        Comment


                          #52
                          Re: higher standby voltage on a phillips tv power supply

                          but if play videos with bright movements. Buzzing get louder. Depends on the brightness and contrast.

                          Comment


                            #53
                            Re: higher standby voltage on a phillips tv power supply

                            Tested everything else including caps. This is the only thing buzzing. The rest all seems fine. The transformer gets pretty hot though.
                            Attached Files
                            Last edited by DjKrish; 08-09-2020, 02:57 AM.

                            Comment


                              #54
                              Re: higher standby voltage on a phillips tv power supply

                              Is that a crack on the transformer. Others have had ferrite transformers that have cracked possibly from overheating of the windings. There is a post on the forum regarding this issue.
                              Last edited by dick_barton; 08-09-2020, 05:10 AM.
                              Willing to help but I'm no expert.

                              Comment


                                #55
                                Re: higher standby voltage on a phillips tv power supply

                                Originally posted by dick_barton View Post
                                Is that a crack on the transformer. Others have had ferrite transformers that have cracked possibly from overheating of the windings. There is a post on the forum regarding this issue.
                                Haha no. Thats just a scratch. Seems like an aluminum plate to take heat.

                                Comment


                                  #56
                                  Re: higher standby voltage on a phillips tv power supply

                                  1) If you push the transformer body with wooden stick, does it change the pitch?

                                  2) Monitor the PFC Boost Voltage on the main filer cap to see if it is around 380 ~ 400VDC and see if it goes up and down with the buzz level, do the same on the 24V output. see if it goes up and down too.

                                  3) Check the DCV on the connector CN 4 Pin 10 BL-DIM1 when you change the brightness or contrast setting to see which one affect the BL-dim control signal, you need to use static Video source to do this test, also turn off Dynamic backlight.
                                  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


                                    #57
                                    Re: higher standby voltage on a phillips tv power supply

                                    Originally posted by budm View Post
                                    1) If you push the transformer body with wooden stick, does it change the pitch?

                                    2) Monitor the PFC Boost Voltage on the main filer cap to see if it is around 380 ~ 400VDC and see if it goes up and down with the buzz level, do the same on the 24V output. see if it goes up and down too.

                                    3) Check the DCV on the connector CN 4 Pin 10 BL-DIM1 when you change the brightness or contrast setting to see which one affect the BL-dim control signal, you need to use static Video source to do this test, also turn off Dynamic backlight.
                                    Ah finally. Its this fella thats making the noise, not the big one. When i press this guy with a stick, sound stops. And also what suppose to be 24v is showing 25.3v. Is that normal?
                                    Attached Files

                                    Comment


                                      #58
                                      Re: higher standby voltage on a phillips tv power supply

                                      Should i dip the small fella in varnish and dry it?

                                      Comment


                                        #59
                                        Re: higher standby voltage on a phillips tv power supply

                                        That is one of the two Boost converter inductor that boost the Voltage to drive one of the two LED strings, this one drives that set of four wires counting from the left of the LED connector, the 4th wire has long exposed wire that I mention before.. Some one trying to fix that section may be that is why the wire is exposed like that, no way the insulation of the wire can be that much removed by itself.
                                        Jut swap that inductor with another inductor to see if the noise will move to the new location or not first.
                                        BTW, you should put insulation tape on that exposed wire before it is shorted to the chassis and causes damages.

                                        Also look real close to see if that exposed wire is still properly crimped to the terminal.

                                        "what suppose to be 24v is showing 25.3v. Is that normal?" That is fine, it is not tightly regulated power supply.
                                        Last edited by budm; 08-09-2020, 11:54 PM.
                                        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


                                          #60
                                          Re: higher standby voltage on a phillips tv power supply

                                          Originally posted by budm View Post
                                          That is one of the two Boost converter inductor that boost the Voltage to drive one of the two LED strings, this one drives that set of four wires counting from the left of the LED connector, the 4th wire has long exposed wire that I mention before.. Some one trying to fix that section may be that is why the wire is exposed like that, no way the insulation of the wire can be that much removed by itself.
                                          Jut swap that inductor with another inductor to see if the noise will move to the new location or not first.
                                          BTW, you should put insulation tape on that exposed wire before it is shorted to the chassis and causes damages.

                                          Also look real close to see if that exposed wire is still properly crimped to the terminal.

                                          "what suppose to be 24v is showing 25.3v. Is that normal?" That is fine, it is not tightly regulated power supply.
                                          Ok, swapped the inductor. Now the sound is back to this side So its confirm the inductor varnish id dried up. As for the main caps, on both are 386V. Already insulated the exposed wire. Yes the exposed wire is properly crimped to the terminal, add more, i just resoldered it. to make sure its not loose.
                                          Last edited by DjKrish; 08-10-2020, 12:27 AM.

                                          Comment

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