Samsung PN64D8000 - Power Supply Board Issue?

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • overdrive1012
    Member
    • Jun 2018
    • 22
    • USA
    #1

    Samsung PN64D8000 - Power Supply Board Issue?

    We were watching TV the other night when I heard a pop followed by the TV going out. No standby light, nothing.

    Immediately, I opened the back and noticed that one of the fuses on the board (BN44-00447A) had blown. I thought I could replace the fuse and cross my fingers that nothing else was bad. I replaced the fuse and plugged in the TV, immediately the other one popped. I replaced that one and plugged back in and this time around I heard/saw a pop, which tripped the circuit breaker. This time around, a thermistor blew.
    I'm thinking that before I replace that thermistor, something else is amiss.

    It seems that these boards are a little hard to come by and not cheap. It's been a little while since I picked up a soldering iron (last time I did, I accidentally fried a PS2) so I'm hoping I can get some guidance on where to start.

    Thanks,
    J
    Tags: None
    • CapLeaker
      Leaking Member
      • Dec 2014
      • 8146
      • Canada
      #2
      Re: Samsung PN64D8000 - Power Supply Board Issue?

      Usually there is a reason why a fuse pops. So keep putting in fuses you may do more damage. First off you have to figure out "WHY" the PSU keeps popping fuses. So first logical thing is to do is to make some straight shot, high resolution pictures of your boards front and back, so we can see things clearly. Check the primary section of the PSU. Be careful, there can be very high voltages when plugged in and running. Fist item to check on your PSU in this case is the bridge rectifier for a short. If that is shorted, it's bad.

        Comment

        • R_J
          Badcaps Legend
          • Jun 2012
          • 9535
          • Canada
          #3
          Re: Samsung PN64D8000 - Power Supply Board Issue?

          What "thermistor" blew, it was likey an MOV. what was its location number or part number on the component. These boards also develope bad solder connections on the transformers and mosfets mounted to the heat sinks, they need resoldering especially the connections that use a rivit.

            Comment

            • overdrive1012
              Member
              • Jun 2018
              • 22
              • USA
              #4
              Re: Samsung PN64D8000 - Power Supply Board Issue?

              This is the thermistor that blew. I'm going to pull the board and see if I can see any other damage.

                Comment

                • overdrive1012
                  Member
                  • Jun 2018
                  • 22
                  • USA
                  #5
                  Re: Samsung PN64D8000 - Power Supply Board Issue?

                  Sorry, didn't attach the image. DSC 20D-20 Thermistor. See the blow hole on the bottom right side.
                  Attached Files

                    Comment

                    • R_J
                      Badcaps Legend
                      • Jun 2012
                      • 9535
                      • Canada
                      #6
                      Re: Samsung PN64D8000 - Power Supply Board Issue?

                      Ok, that one is the thermistor, Also check the resistance across the blue mov's maybe one of them shorted also, if not just replace the thermistor and don't forget to check or resolder those connections I mentioned.

                        Comment

                        • overdrive1012
                          Member
                          • Jun 2018
                          • 22
                          • USA
                          #7
                          Re: Samsung PN64D8000 - Power Supply Board Issue?

                          Also have a blown MOSFET. See the pinhole and the char mark.
                          Attached Files

                            Comment

                            • R_J
                              Badcaps Legend
                              • Jun 2012
                              • 9535
                              • Canada
                              #8
                              Re: Samsung PN64D8000 - Power Supply Board Issue?

                              That would do it. Did you have a look at those other connections for cold solder joint? I bet one of the connections on TS801s primary is bad.
                              Last edited by R_J; 06-15-2018, 04:49 PM.

                                Comment

                                • overdrive1012
                                  Member
                                  • Jun 2018
                                  • 22
                                  • USA
                                  #9
                                  Re: Samsung PN64D8000 - Power Supply Board Issue?

                                  So, impatient as I am, I ended up picking up a TV on craigslist that had a broken panel for $30. Power supply was good so I just swapped it to this one and I'm back in business, but will eventually fix this one as a backup.

                                    Comment

                                    Previous template Next

                                    Related Topics

                                    Collapse
                                    • Tynan Dill
                                      Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?
                                      by Tynan Dill
                                      I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.

                                      Upon bringing it home and plugging it up, it showed a standby light.

                                      I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.

                                      The screen seems to blackout and stay black, but with a flashlight I can see the display.

                                      With my Playstation 4 connected via HDMI, and running a game I can hear sound.

                                      Assuming...
                                      ORIGINAL POWER SUPPLY BOARD
                                      7 Photos
                                      11-22-2024, 01:46 PM
                                    • Nicktronic
                                      Samsung Power Supply Board BN44-00874F
                                      by Nicktronic
                                      Hey everyone,

                                      This power supply board is hard to find but there are repair kits available. This board had a blown fuse, FP801S, blown PFC MOSFET, QP802CS and ceramic cap, CP809. I replaced them with parts I already had and tested the rest of the parts that would've come in the repair kit and they were fine. I powered the board up on the bench expecting, in typical Samsung power supply board fashion, to see all my output voltages but, nothing. 0 volts on CNL801, CNM801 and CNT801. The only thing I have is 170vdc on the filter caps. No standby voltage either.

                                      Anybody...
                                      03-17-2025, 06:20 AM
                                    • Asraf Atb
                                      Help Needed: Samsung UE55MU8000 Dead - Possible Main Board Issue
                                      by Asraf Atb
                                      Hi everyone,

                                      Im looking for some advice regarding my Samsung UE55MU8000 TV with main board model BN94-11606C. The TV suddenly stopped turning on and now shows no signs of life at all not even the standby light at the bottom.

                                      Initially, I suspected an issue with the PSU, so I took it to a repair center. They tested it and confirmed that the PSU works perfectly, even on other TVs. Based on that, I started investigating the main board.

                                      I disconnected the main board from the PSU, and the backlight turned on, which seems to confirm the main board is the issue....
                                      1 Photo
                                      01-27-2025, 05:02 PM
                                    • sam_sam_sam
                                      Panasonic switching power supply daughter board has two 27uf @ 50 volt capacitors which I do not keep in stock
                                      by sam_sam_sam
                                      I did not have any 27uf @ 50 volt capacitors but one nice thing is that it has enough room for two capacitors in parallel a 22uf and a 4.7uf @ 50 volts 22 plus 4.7 equals 26.7uf which so very close to 27uf I will show some pictures of it sometime tomorrow

                                      This is one of the shit est boards I seen in a very long time and it was the daughter board the traces just lifting off the board I had to use the capacitor leads to repair the the traces and the main board is not any better because I had to repair several traces for the daughter board to the main board

                                      After all of...
                                      07-13-2024, 08:14 PM
                                    • repair-it
                                      Need advice testing a samsung power supply board with scope
                                      by repair-it
                                      I am attempting to test a samsung power supply board to verify the pfc ic is working. I am powering up the board with my isolation transformer. The board turns on fine but when I attempt to connect the ground for the scope probe, it trips out the isolator. I was taught not to 'float my scope' so I am wondering if I should test without connecting the ground lead or would that be asking for trouble? Not sure how else to test, I don't have a portable scope. I could plug direct to mains power but that would bypass the safety factor.
                                      07-12-2025, 11:00 AM
                                    • Loading...
                                    • No more items.
                                    Working...