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Pioneer VSX-520-K Protection problem

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    #81
    Re: Pioneer VSX-520-K Protection problem

    Originally posted by rievax_60 View Post
    Ok, that helps to make sense of the voltages. The leakage has to be between collector and base pads of Q444. Try to clean it again. Do you have any information about the flux?
    That was a mistake. The leakage would have to be between collector and emitter.

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      #82
      Re: Pioneer VSX-520-K Protection problem

      Originally posted by rievax_60 View Post
      Ok, that helps to make sense of the voltages. The leakage has to be between collector and base pads of Q444. Try to clean it again. Do you have any information about the flux?
      Flux shows neutral PH7+-0.3..so i think its neutral

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        #83
        Re: Pioneer VSX-520-K Protection problem

        Did the PCB get burnt under Q444?

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          #84
          Re: Pioneer VSX-520-K Protection problem

          Originally posted by rievax_60 View Post
          Ok, that helps to make sense of the voltages. The leakage has to be between collector and base pads of Q444. Try to clean it again. Do you have any information about the flux?
          Flux shows neautral..its written ther PH+-.3

          Comment


            #85
            Re: Pioneer VSX-520-K Protection problem

            Originally posted by rievax_60 View Post
            Did the PCB get burnt under Q444?
            Yes littile burn mark ther

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              #86
              Re: Pioneer VSX-520-K Protection problem

              Originally posted by srt1 View Post
              Yes littile burn mark ther
              I would use a small drill bit to remove the burnt paper from between the collector and emitter pads.

              Comment


                #87
                Re: Pioneer VSX-520-K Protection problem

                Originally posted by rievax_60 View Post
                I would use a small drill bit to remove the burnt paper from between the collector and emitter pads.
                I am.trying to remove the burn mark..and let you know the result

                Comment


                  #88
                  Re: Pioneer VSX-520-K Protection problem

                  Originally posted by srt1 View Post
                  I am.trying to remove the burn mark..and let you know the result
                  Hi.. i replace the 2sa684(q444) with a92 now problem soleved ther is no leakage current. I think 2sa684 for not suitable for this apllication as the maximum volatage on Vceo is 50 but in this circuit its 54volt i think thats why this leakage current but for a92 Vceo is 300 volt.any way thanks alot for your support i apriciate it..may be tomorrow i will get correct tramsistors ie. A992..then i wil replace it

                  Comment


                    #89
                    Re: Pioneer VSX-520-K Protection problem

                    The 2SA684 would not have had any leakage and there was no indication that Q443 was leaky. If the PCB was charred, you should confirm it. I like things to make complete sense where possible.
                    It is best to use the correct transistors.
                    Last edited by rievax_60; 09-15-2017, 06:01 AM.

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                      #90
                      Re: Pioneer VSX-520-K Protection problem

                      Originally posted by rievax_60 View Post
                      The 2SA684 would not have had that much leakage and there was no indication that Q443 was leaky. If the PCB was charred, you should confirm it. I like things to make complete sense where possible.
                      It is best to use the correct transistors.
                      Yes i done cleaning and same time i replaced transistor also ..i think you are right may be black mark cause leakage ..but any way i will replace with correct transitor tomorrow.because if i put back 2sa684 for testinfg freequent removal causing traces damage..

                      Comment


                        #91
                        Re: Pioneer VSX-520-K Protection problem

                        Today i got onkyo sr 313 and pioneer vsx 1122 both are ahutdown itself after power ..i will open another thread for discission..

                        Comment


                          #92
                          Re: Pioneer VSX-520-K Protection problem

                          What Voltage do you have at the Base of Q437 compared to working channels?
                          What are the Voltages at the Collector of Q443, 444 compared to working channels?
                          Last edited by budm; 09-15-2017, 09:30 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


                            #93
                            Re: Pioneer VSX-520-K Protection problem

                            Originally posted by budm View Post
                            What Voltage do you have at the Base of Q437 compared to working channels?
                            What are the Voltages at the Collector of Q443, 444 compared to working channels?
                            At base of q437 was around 49 volt with respect to ground.and cillector pin of q443 444 is -53volt .its almost same comoared to other channel..

                            Comment


                              #94
                              Re: Pioneer VSX-520-K Protection problem

                              So those Voltage readings on all those 3 location as I request show about (within 1V) the same as in the working channels. There must be some readings in that section that is/are not the same as working channels.
                              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


                                #95
                                Re: Pioneer VSX-520-K Protection problem

                                Originally posted by budm View Post
                                So those Voltage readings on all those 3 location as I request show about (within 1V) the same as in the working channels. There must be some readings in that section that is/are not the same as working channels.
                                Yes that is at base of q443 q444 and at the emitter tied

                                Comment

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