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Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

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    #21
    Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

    As I indicate thee board in question does not have PFC, but you still have SMPS circuit that will still generated the back EMF by that power transformer, please read up on when happen when energize and deenergize inductor then you will understand why they put in the 1000V higher cap in that section. That cap is exposed to much higher that 330vdc.
    http://i.stack.imgur.com/REXp2.png look at c12 which has the same function as CM804 of your power supply board.

    http://electronics.stackexchange.com...details/254675

    https://cdn.badcaps-static.com/pdfs/...4fc807c47b.pdf
    See page 13, (F) = Voltage across the MOSFET Q1
    BTW, common failure mode of ceramic cap is shorted circuit.
    Last edited by budm; 11-12-2016, 04:40 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


      #22
      Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

      Originally posted by Chungalin View Post
      Let me question the cause-effect order of this apparently recurrent failure. If ceramic capacitor is 1KV rated, and the TV is powered from 230V AC, at that point of the PSU there's nothing that can generate more than 1000V. I'm starting to think that it's the capacitor that fails first. The IC gets shorted because the cap shorts briefly before blowing to bits. What else can make a ceramic capacitor explode this way?

      I see no problem in removing the white insulation glue. I use a small flat screwdriver to remove some big chunks and then I unsolder the IC. Once all legs are unsoldered, just pull the IC and all the glue that comes with it.
      Thanks for the tip, will try to get the last gunk off after desoldering the bad parts, still waiting for the replacement parts.

      I was just assuming the STR-W6052S failed first because in my experience with power supplies MOSFETs usually fail while ceramic capacitors rarely do so.

      After looking at the datasheet for STR-W6052S I'm starting to understand it a little better, they have sample schematics in there which seems to match the board. I'm a bit of a rookie with this type of circuit though, anything involving high voltage stuff. On the bright side, at least I learned something new today, figured out what a "damper snubber" cap is.

      Comment


        #23
        Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

        "usually fail while ceramic capacitors rarely do so. " if look through lots of threads at BC and fix lots of circuit in that power supply section you will this type of caps failed in this application and we also recommend going with even higher Voltage rating.

        "After looking at the datasheet for STR-W6052S I'm starting to understand it a little better, they have sample schematics in there which seems to match the board. I'm a bit of a rookie with this type of circuit though, anything involving high voltage stuff. On the bright side, at least I learned something new today, figured out what a "damper snubber" cap is."
        You should also look at the board and see how cap CM 804 is connected to the STR also, it is basically connected across the switch (Source and Drain, Pin 1 and pin 3 of the STR) in this case it is the internal power MOSFET inside the STR.
        Attached Files
        Last edited by budm; 11-12-2016, 08:21 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


          #24
          Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

          OK, the LCD TV (Samsung model UA23F4003AR) works again, thanks for the help.

          I had to replace the power IC (STR-W6052S), capacitor 220pF/1000V (CM804), resistor 0.36 Ohm (RM803), and the fuse 2A/250V (FP802S). Also had to solder a wire to fix a PCB trace that had burned off between resistor RM803 and the heat sink point for STR-W6052S.

          Comment


            #25
            Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

            Hi All.
            I have the same power supply. After a power surge burned a lot. Help determine the capacitor SM853, it is not on the board, after another workshop.
            Sorry for the translation in Google.
            Thank you for your help.

            Comment


              #26
              Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

              Originally posted by bansai View Post
              Hi All.
              I have the same power supply. After a power surge burned a lot. Help determine the capacitor SM853, it is not on the board, after another workshop.
              Sorry for the translation in Google.
              Thank you for your help.
              Hello,
              A have the same board as you and there is no SM853 capacitor.
              On the other hand there is a CM853 capacitor (electrolytic, 47 microF, 50V).

              Comment


                #27
                Samsung BN44-00505A(PD23A0Q) psu

                Bn44-00505a
                Attached Files

                Comment


                  #28
                  Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                  Can anyone help-me with this borad to?!
                  my problem is DM861 (SR320 ), I replace it but it burns.. any idea ?!

                  Comment


                    #29
                    Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                    I can't see the type of diode DM855 snd DM852 ,can anyone tell me the type or sent me the service manual?

                    Comment


                      #30
                      Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                      Good afternoon, I have a question, I have a BN44-00505A source but bring the strw6053s, in my country I am not getting it, I also burn the capacitor 220pF / 1000V (CM804), the resistance of 0.36 Ohm (RM803), my question is the Next can I replace the 6053s with the 6052s? , my doubt is the difference of watts that the two integrated handle, I hope a quick response, thank you very much.

                      Comment


                        #31
                        Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                        STR-W6052S is 60W, while STR-W6053S is 90W, this is why it's not safe to replace 6053 with a 6052. But you can replace 6052 with a 6053.

                        Comment


                          #32
                          Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                          Originally posted by magos21 View Post
                          I can't see the type of diode DM855 snd DM852 ,can anyone tell me the type or sent me the service manual?
                          DM852? Do you mean DM853?

                          DM855 is SF36G.

                          Το έφτιαξες;

                          Comment


                            #33
                            Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                            Hi All,
                            For the record, and help someone, i replace the rectifier bridge was short circuit, the fuse was open, put new one, the diode DM801 was with dark burned area, replaced, the CM804 was with visible crack, replaced and after all this, didn't start. I replaced the STRW 6052S and, worked.

                            Comment


                              #34
                              Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                              My Samsung T24B301EW broke, blue status LED is on, so there is some power, if trying to switch it on the LED blinks 3-4 times slower then blinks very fast, nothing happens.

                              Found this thread, trying to understand, whats going on.

                              Took a look at my PSU BN44-00505A, some pictures here: https://imgur.com/a/AnmN8sD

                              CM855 seems to be damaged, could it be the only reason for behaviour? Can you pro people maybe spot other damage or suggest which parts I should inspect further?

                              Trying to locate other parts mentioned in thread, seems I can not find that STR-W6052S, any hint where to look?

                              Am a beginner, not totally clueless but bare with me please, have soldering iron and simple voltmeter. Managed to fix a dead old harddisk a few month ago with motivation from Louis Rossmann videos, "just try it" attitude, a lot of google, ordering and exchanging mainboard and switching smd rom chip with borrowed hotair station.
                              Last edited by roberto77; 09-17-2020, 02:04 PM.

                              Comment


                                #35
                                Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                                FYI, replaced CM855 with a new 10 V 1200 uF, TV works again.

                                Comment


                                  #36
                                  Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                                  Originally posted by xipbox View Post
                                  Can anyone help-me with this borad to?!
                                  my problem is DM861 (SR320 ), I replace it but it burns.. any idea ?!
                                  Hello! I have the same problem, is the QM861 it´s in short circuit, but i cant see the reference,,, i need the service manual or the ref. anyone?

                                  Comment


                                    #37
                                    Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                                    Hi All,
                                    First time posting , i would like to thank all of you in this forum giving your experience and knowledge to all of us .My TV is T22B350EW and the power supply is BN44-00505A(PD23A0Q) , i replaced the rectifier bridge it was short circuit replaced , the fuse was open, put new one, replaced the CM804 was with visible crack, replaced the STRW 6052S and , worked.

                                    Comment


                                      #38
                                      Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                                      Originally posted by Chungalin View Post
                                      I have replaced IC STR-W6052S, ceramic cap [CM804] (0.22nF 1000V "221K 1KV") and the TV is working again.
                                      Same happened to me, burned Ceramic Cap, but no VCC on switcher, so replacing both IC and cap, worked again.

                                      Many thanks for your help, this thread helped me a lot.

                                      Comment


                                        #39
                                        Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                                        Hello guys!

                                        I had the same problem. CM804 was blown but it was a 331 2K and not 221 1K. Maybe someone else had replaced it before, so I replaced it with a 331 2K. I also replaced the fuse with a 4A and the RM803 with 0.33 Ω.

                                        I plugged the power and the fuse blew again.

                                        Have I to replace the STR-W6052S and the CM804 with a 221 1K too?

                                        Thanks in advance!!
                                        Attached Files

                                        Comment


                                          #40
                                          Re: Samsung BN44-00505A(PD23A0Q) psu, smd transistor types

                                          Can top-245yn be used instead of str-6052s?

                                          Comment

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