Samsung U60J620DAF Power and Backlights blink

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #41
    Re: Samsung U60J620DAF Power and Backlights blink

    Originally posted by MEB
    Pin 1 - UD - +13V
    Pin 3 - PWM-BLU - +13V
    Pin 5 - PS_ON - +13V
    Pin 7 - +13V
    Pin 9 - GND = 0 volts

    These were taken with the black lead on pin 10 GND.
    PS board is only attached to AC.
    You must have counted the connector wrong that is why those reading are wrong, no way the control signals can be 13V, please recheck your connector pins.
    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

    • MEB
      Badcaps Veteran
      • Sep 2013
      • 371
      • USA

      #42
      Re: Samsung U60J620DAF Power and Backlights blink

      Thanks. I will report back after I get home tonight.

      Comment

      • MEB
        Badcaps Veteran
        • Sep 2013
        • 371
        • USA

        #43
        Re: Samsung U60J620DAF Power and Backlights blink

        Yes, I did.

        Pin 2 - UD = 2.31 V
        Pin 4 - PWM_BLU = 3.28 V
        Pin 6 = 3.88 V

        Pins 1,3,5 and 7 = 12.77 V

        Also center leg of DM851C = 12.7 V

        Hope this is better.
        Attached Files

        Comment

        • jason123
          Badcaps Legend
          • Oct 2015
          • 1040
          • USA

          #44
          Re: Samsung U60J620DAF Power and Backlights blink

          Hi MEB, any update on this? I have a 40" that is acting the same - flashing backlight. Thanks

          Comment

          • MEB
            Badcaps Veteran
            • Sep 2013
            • 371
            • USA

            #45
            Re: Samsung U60J620DAF Power and Backlights blink

            https://www.youtube.com/watch?v=1kwPFr1VXOo

            jason123 Not really. I tried another PS board and it did the same thing. Now I have led issues. The above link is a short video I found, but gives no fix or suggestions.

            Comment

            • vinceroger69
              Badcaps Legend
              • Mar 2012
              • 6714
              • uk

              #46
              Re: Samsung U60J620DAF Power and Backlights blink

              im sure i saw a video on youtube yesterday regarding samsung flashing back lights they removed the pwm wire from the connector and all was fine i know this isnt a fix as cant alter backlight but did stop the flashing i will see if i can find the video again

              Comment

              • MEB
                Badcaps Veteran
                • Sep 2013
                • 371
                • USA

                #47
                Re: Samsung U60J620DAF Power and Backlights blink

                I have done a complete 360 since starting this. Started out with flashing LEDS and am back to flashing LEDS. If it was the power supply, replacing it with another had the same exact results. Some new strips failed on initial power up, but putting some of the originals back in and all testing good, the LEDS all light with either power supply but flash just the same. The main board is disconnected so it can only be the PSs are both bad and have failed in exactly the same way? I am confused.

                Comment

                • nomoresonys
                  Badcaps Legend
                  • Jan 2013
                  • 12081
                  • U.S.

                  #48
                  Re: Samsung U60J620DAF Power and Backlights blink

                  Check all the solder joints with a magnifying glass.

                  Comment

                  • nomoresonys
                    Badcaps Legend
                    • Jan 2013
                    • 12081
                    • U.S.

                    #49
                    Re: Samsung U60J620DAF Power and Backlights blink

                    With all boards connected and tv unplugged, check those little brown capacitors on tcon board for shorts, meter on diode mode, probe on each end of capacitor.

                    Comment

                    • budm
                      Badcaps Legend
                      • Feb 2010
                      • 40746
                      • USA

                      #50
                      Re: Samsung U60J620DAF Power and Backlights blink

                      So based on your post 34 & 36 when you test the LED strips outside the panel and powered by the power supply board; they light up OK without flashing ? correct?
                      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

                      • MEB
                        Badcaps Veteran
                        • Sep 2013
                        • 371
                        • USA

                        #51
                        Re: Samsung U60J620DAF Power and Backlights blink

                        Sorry to be confusing. I tested both strings with little led tester with the power supply to LED connector disconnected from the power board. I could light both strings up that way. When powering LEDs from either one of the 2 Power Supply boards I have, LEDs (both strings) always flash. This is with the LED connector connected to the PS board and the main board disconnected from the Power Supply board.

                        So, with the PS board connected to the LEDs, whether the main is connected or not, always gives flashing LEDs.

                        Comment

                        • MEB
                          Badcaps Veteran
                          • Sep 2013
                          • 371
                          • USA

                          #52
                          Re: Samsung U60J620DAF Power and Backlights blink

                          OK. I checked all the solder joints on the PS board and saw nothing alarming. It was kind of hard to see with the silicone looking stuff they dumped over the back of the board. I did touch up the 2 connectors though they looked fine. Put the board back in and still have the flashing LEDs.

                          Then I removed the T-Con board so I could get the heatsink off to get to the capacitors underneath and reconnected it back up. I had to get a microscope to see anything, but I tested every capacitor on the board as instructed and none of them were shorted or visually damaged. I put new heat sink grease on the heatsink and re-installed everything. LEDs are still flashing.

                          Since the LEDs flash whether or not the main and thus the T-Con board are disconnected or not, doesn't the problem have to be the power supply, the LED wires/strips or failed LEDs ? I sometimes get an idea stuck in my head, so if I am missing something, please tell me. Thanks for all the help.

                          Comment

                          • budm
                            Badcaps Legend
                            • Feb 2010
                            • 40746
                            • USA

                            #53
                            Re: Samsung U60J620DAF Power and Backlights blink

                            When you perform self test for the power supply/LED driver/LED's by disconnecting the cable between Power supply and the main board, so T-CON or any other boards have nothing to do with self test mode.
                            So far I have no luck finding fast-track for this model.
                            Too bad you cannot do the test of the LED strips connected to the power supply board outside the panel to see what you are seeing, using LED tester at low current to test the LED strips is not 100% reliable due to only 30mA of drive current instead of 200 ~ 300mA of real drive current.
                            When I test the new LED strips, I drive them with the power supply board in self test mode with the LCD panel not in place for 15 minutes to make sure the new LED strips will hold up.
                            Last edited by budm; 12-28-2018, 06:41 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

                            • MEB
                              Badcaps Veteran
                              • Sep 2013
                              • 371
                              • USA

                              #54
                              Re: Samsung U60J620DAF Power and Backlights blink

                              Thanks, bud. The LEDs have all been lighting in the panel connected to the power supply but continue flashing. I removed the power supply again and removed all the electrolytics. They all tested fine. I ordered new ones to replace all of them just to eliminate them being a possibility. With the power supply back in and powering it up unconnected to anything else but the LEDs, a noise came from the panel, and using the LED tester, I determined the top string of LEDs wouldn't light. This is the second time I have lost the top string. I will take the panel apart again to see what happened.

                              My wife has issued an ultimatum. I have less than 2 weeks to fix this or I have to buy a new TV before the Super Bowl. I have to fix this one regardless of the outcome of that but am nearly out of ideas.

                              I ordered another set of strips from SJ and they will probably be here Wednesday. I will test them outside the panel as you suggested this time. Before I do, I want to have a fairly good feeling about the power supply. Can I test the following voltages without burning something up with nothing but AC connected to the board, and what should I expect to see. D+ to D-, D+ to chassis and D- to chassis. I think I should also check the actual wires from the power supply to the LEDs. Also is there any advantage to placing a voltmeter in the circuit to monitor current. I doubt I might be fast enough to pull the plug before damage would occur but was just wondering. This little adventure is getting quite costly but I can't stop now. Thanks for your help.

                              Comment

                              • MEB
                                Badcaps Veteran
                                • Sep 2013
                                • 371
                                • USA

                                #55
                                Re: Samsung U60J620DAF Power and Backlights blink

                                Aha, seems like the first new set of strips I bought had problems. I put 3 of the good originals and 3 of the good new ones in there and it is working. As budm eluded to, I think even though the bad strips tested fine under low current with the little led tester, when the PS board was used, they failed under high current.
                                I think the original problem of the LEDs flashing on and off, must have been some protection circuit on the PS board that shut down and started over and over in a vicious loop. Is that possible?

                                So I didn't need the 2nd new set of strips I just received, but I am going to put them in there anyway. I don't want to have to do this again any time soon. Thanks to all who helped.
                                Attached Files

                                Comment

                                • nomoresonys
                                  Badcaps Legend
                                  • Jan 2013
                                  • 12081
                                  • U.S.

                                  #56
                                  Re: Samsung U60J620DAF Power and Backlights blink

                                  Nice job, seems like it's the backlights 99 percent when you have flashing issues.

                                  Comment

                                  • nomoresonys
                                    Badcaps Legend
                                    • Jan 2013
                                    • 12081
                                    • U.S.

                                    #57
                                    Re: Samsung U60J620DAF Power and Backlights blink

                                    Originally posted by MEB
                                    Aha, seems like the first new set of strips I bought had problems. I put 3 of the good originals and 3 of the good new ones in there and it is working. As budm eluded to, I think even though the bad strips tested fine under low current with the little led tester, when the PS board was used, they failed under high current.
                                    I think the original problem of the LEDs flashing on and off, must have been some protection circuit on the PS board that shut down and started over and over in a vicious loop. Is that possible?

                                    So I didn’t need the 2nd new set of strips I just received, but I am going to put them in there anyway. I don’t want to have to do this again any time soon. Thanks to all who helped.
                                    Ah, suspected this in post #35. Even shopjimmy sends out faulty parts on occasion BUT they stand behind their parts and will try to make it right.
                                    Last edited by nomoresonys; 01-28-2019, 08:12 AM.

                                    Comment

                                    • MEB
                                      Badcaps Veteran
                                      • Sep 2013
                                      • 371
                                      • USA

                                      #58
                                      Re: Samsung U60J620DAF Power and Backlights blink

                                      Thanks, I learned some things and will know better what to look for next time.

                                      Comment

                                      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...
                                        11-22-2024, 01:46 PM
                                      • PantherDave
                                        Microsoft Surface Pro (5th gen) model 1796 - no power
                                        by PantherDave
                                        Hi all!

                                        I'm trying to troubleshoot a Microsoft Surface Pro (5th gen) model 1796 that won't power on. Motherboard model is M1007506-015. My priority is retrieving data, but the SSD is integrated so it looks like if I can't repair it it'll need to go to a data recovery company. I've done a little basic board repair before, but nothing this advanced until now. So please forgive my ignorance in advance. πŸ˜…

                                        I found the boardview for this laptop in the forums here, and am able to open it on my PC with FlexBV.
                                        https://www.badcaps.net/forum/troubl...-hardware-devi...
                                        05-29-2024, 02:01 PM
                                      • GLISIT
                                        Asus Probook P5440UF-XB74 power issue
                                        by GLISIT
                                        Hi all,

                                        TL;DR - this laptop is driving me nuts with the oddball power-related behaviors. Appreciate any insight you can provide!


                                        I'm experiencing a power issue on an Asus Probook P5440UF-XB74. Although I've worked with electronics and computers for decades, this is my first attempt at getting into motherboard-level component troubleshooting. Any help the community can provide is greatly appreciated!

                                        A few weeks ago I was using the laptop (on battery power) for a Zoom meeting. The battery was running very low (long meeting) but I wasn't worried about...
                                        01-16-2025, 02:29 PM
                                      • nathan425
                                        Samsung UN50EH5300 - No Standby LED, Backlights ON, No Power
                                        by nathan425
                                        Hello, I have a Samsung UN50EH5300 in my possession that I'm looking to bring back to life.

                                        Symptoms:
                                        • - no power
                                        • - no standby LED


                                        What I've done so far:
                                        - confirmed power supply is OK
                                        -- CN201 #4 showing 5.3V
                                        -- BD207 showing 5.3V
                                        -- removing the cable between the main board and the power board turns on the backlight.

                                        Pushing the power button on results in no change to any of the pins connecting the two boards.

                                        - function assembly appears to be NO GOOD
                                        -- there is no voltage showing on any of...
                                        11-01-2023, 06:34 PM
                                      • hill01
                                        Samsung UE75MU7009TXZG Endless Power Cycle
                                        by hill01
                                        Samsung UE75MU7009TXZG Endless Power Cycle

                                        Hi everyone and thanks in advance for any help I might get here

                                        My Samsung TV is about 4 years old. The exact model number is UE75MU7009TXZG.
                                        About half a year ago I started seeing occasional green frames pop up while watching movies. I mean literally green frames. Not the image turning green, but the entire screen turning green for a split second. This happened maybe once or twice during a 2 hour movie. So no big deal, but clearly something was not quite right.

                                        Since a few days, the TV won't turn...
                                        11-17-2021, 02:52 PM
                                      • Loading...
                                      • No more items.
                                      Working...