Announcement

Collapse
No announcement yet.

How to repair Power board BN44-00503A ?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    How to repair Power board BN44-00503A ?

    Hello there,

    I would like to learn how to repair this power board BN44-00503A. There is 5v Standby, big filter cap measures 396v but there is no voltage out to LED's. This board belongs to Samsung tv model UN55ES6100 and it has the pull up resistor that should allow the backlight to turn on when disconnected from main board.

    Any suggestions of what to check or measure would be appreciated. High definition pictures from Shopjimmy are attached.

    Thanks
    Attached Files

    #2
    Re: How to repair Power board BN44-00503A ?

    Are you quite sure the Pwr Bd is the problem?....Suppose the Bscklights don't work, so the Pwr Bd shuts down to self protect?...The LED driver cct like IC 9101 could be at fault, also....but you should test the backlights first.

    Comment


      #3
      Re: How to repair Power board BN44-00503A ?

      What voltages do you have on CNL802?
      Board says 243V @ 367mA
      Last edited by dick_barton; 01-31-2017, 09:14 AM.
      Willing to help but I'm no expert.

      Comment


        #4
        Re: How to repair Power board BN44-00503A ?

        Originally posted by dick_barton View Post
        What voltages do you have on CNL802?
        Board says 243V @ 367mA
        This would be across pin 1 (+ve DMM probe) and pin 9 (-ve DMM probe).
        It may be momentarily, so connect the DMM probes securely then plug in the 120Vac.

        Comment


          #5
          Re: How to repair Power board BN44-00503A ?

          Hey thank you for the quick responses. So,

          @Andrew, I know the power is def the problem. I had another power board that I got from a cracked screen unit, I installed it and the tv is working now. I just want to learn how to fix this defective board. No voltages at none of the pins of IC9101. Also, 0v when checking power between pin 1 and 9.

          @Dick_Barton, 0v on CNL802.

          Comment


            #6
            Re: How to repair Power board BN44-00503A ?

            What dcv do you have on each pin of the connector CNM803?
            You must report each pin in this format:
            Pin 1 B13 = XXX VDC
            Pin 2 PWM_DIM = XXX VDC
            BTW, these SAMSUNG boards with through hole rivet for the transformer legs and large semiconductor devices and resistors are known for bad solder joints. I always re-solder them.
            Last edited by budm; 01-31-2017, 10:14 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


              #7
              Re: How to repair Power board BN44-00503A ?

              Pin 1 B13 = ov
              Pin 2 PWM = 0v
              Pin 3 B13 = 0v
              Pin 4 B13 = 0v
              Pin 5 Vamp = 0v
              Pin 6 BLU = 0v
              Pin 7 Vamp = 0v
              Pin 8 GND = 0v
              Pin 9 GND = 0v
              Pin 10 GND = 0v
              Pin 11 B5v = 0v
              Pin 12 A5v = 5.1v
              Pin 13 B5v = 0v
              Pin 14 Power On/Off = 3.2v

              Comment


                #8
                Re: How to repair Power board BN44-00503A ?

                Have you checked the fuse FP802S? A photo of your power supply could prove more useful.
                Last edited by dick_barton; 02-01-2017, 07:53 AM.
                Willing to help but I'm no expert.

                Comment


                  #9
                  Re: How to repair Power board BN44-00503A ?

                  Originally posted by Louis82 View Post
                  Pin 1 B13 = ov
                  Pin 2 PWM = 0v
                  Pin 3 B13 = 0v
                  Pin 4 B13 = 0v
                  Pin 5 Vamp = 0v
                  Pin 6 BLU = 0v
                  Pin 7 Vamp = 0v
                  Pin 8 GND = 0v
                  Pin 9 GND = 0v
                  Pin 10 GND = 0v
                  Pin 11 B5v = 0v
                  Pin 12 A5v = 5.1v
                  Pin 13 B5v = 0v
                  Pin 14 Power On/Off = 3.2v
                  Are you sure you do not have B5V? That B5V is tapped off the A5V through switched MOSFET QM854, isnce you do have PS-ON, the B5V should be present right now.
                  Fuse FP802S is OK otherwise you will not have standby Voltage.
                  At the same time time the main board is not sending
                  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


                    #10
                    Re: How to repair Power board BN44-00503A ?

                    Hi Budm.

                    Yes, there is 0 voltage on B5v. Very strange. I already put a good board in the tv and it's now working properly. I still want to learn what is wrong with this board.

                    Comment


                      #11
                      Re: How to repair Power board BN44-00503A ?

                      I will have to trace the circuit from the board, that BU5V is turned on by the PS-ON signal so we need to find out if the circuit in that section such as the OPTO for that circuit is active or not.
                      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


                        #12
                        Re: How to repair Power board BN44-00503A ?

                        OK, I look at the board layout, without B13V present then you will not have B5V.
                        ICM801 drives power transformer TM801S which supplies the B13V, and the Voltage for the LED driver power supply.
                        We need the P/N of that ICM801 mounted on the heatsink so we can get the spec sheet and be able to verify Voltages on that IC.
                        I also see three small lytics caps CM812, 814, ??? in that section, you may want to heat them up with hair dryer for a few minutes and then apply power to the board to see what happen.
                        The key point right now is to get the info of that SMPS IC.
                        Cap CM 813 and resistor RM807 need to be check.
                        BTW, I would like to the pictures of YOUR board.
                        Last edited by budm; 02-02-2017, 10:03 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


                          #13
                          Re: How to repair Power board BN44-00503A ?

                          Ok. Working on what you asked. ICM801 P#: FSFR1700XCL

                          Comment


                            #14
                            Re: How to repair Power board BN44-00503A ?

                            RM807 = 0.5 OHMS
                            How can i test CM813 ?

                            RM807 looks suspicious.

                            Comment


                              #15
                              Re: How to repair Power board BN44-00503A ?

                              Spec sheet.
                              Start checking DCV of each pin with ref to primary circuit GND which is the negative leg of the main filter cap. You are going to be really careful because the legs are really and some of the pin will have close to 400VDC.
                              Attached Files
                              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


                                #16
                                Re: How to repair Power board BN44-00503A ?

                                Originally posted by Louis82 View Post
                                RM807 = 0.5 OHMS
                                How can i test CM813 ?

                                RM807 looks suspicious.
                                Resistor is fine, the cap you will have to check its capacitance off the board.
                                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


                                  #17
                                  Re: How to repair Power board BN44-00503A ?

                                  BTW, it may be better to find out if we have DCV at pin 7 LVcc pin to run the IC or not first, I hate to see accident due to slipping test probes.
                                  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


                                    #18
                                    Re: How to repair Power board BN44-00503A ?

                                    With the black probe on negative side of big filter cap, pin 7 measures 14V.

                                    Comment


                                      #19
                                      Re: How to repair Power board BN44-00503A ?

                                      The start Voltage is 12.5V typ, you have 14V so that should make the IC run.
                                      What do you have on pin 2 LS (Line sense)? It needs to be 2.5VDC
                                      Last edited by budm; 02-02-2017, 11:58 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


                                        #20
                                        Re: How to repair Power board BN44-00503A ?

                                        Pin 1 = 396v
                                        Pin 2 = 13.64v
                                        Pin 3 = 13.71
                                        Pin 4 = 0v
                                        Pin 5 = 13.77
                                        Pin 6 = 13.77
                                        Pin 7 = 14v
                                        Pin 8 =
                                        Pin 9 = 13.78
                                        Pin 10 = 14.18v

                                        Comment

                                        Working...
                                        X