intermitted shutdown at high brightness

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  • Demonata08
    Senior Member
    • Jan 2019
    • 116
    • USA

    #1

    intermitted shutdown at high brightness

    Just curious. What board is typically at fault in a lcd tv that shuts down around 10-20 minutes. It turns right back on and normally works fine after it goes off. Lowering the brightness seemed to elevate the issue.

    all caps on the P board and the voltage is all good. I can post pictures if needed but im just curious what the typical issue is.
  • diif
    Badcaps Legend
    • Feb 2014
    • 6978
    • England

    #2
    Re: intermitted shutdown at high brightness

    Faulty LED(s)

    Comment

    • petehall347
      Badcaps Legend
      • Jan 2015
      • 4422
      • United Kingdom

      #3
      Re: intermitted shutdown at high brightness

      turn back lights down problem solved for now and x amount of time .

      Comment

      • Demonata08
        Senior Member
        • Jan 2019
        • 116
        • USA

        #4
        Re: intermitted shutdown at high brightness

        Originally posted by diif
        Faulty LED(s)
        It fails after about 2 minutes even if the panel isnt plugged up and just with the backlight. with it unplugged i can still hear the sound. it goes off at the same speed ><

        the voltage is steady 13 until it recieved the error signal. thinking its the main board at the moment

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA

          #5
          Re: intermitted shutdown at high brightness

          Makes, model, and pictures will help since we have no idea what you have at all.
          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

          • ducky29
            Badcaps Veteran
            • Dec 2015
            • 370
            • Europe

            #6
            Re: intermitted shutdown at high brightness

            Is it LG?

            Comment

            • Demonata08
              Senior Member
              • Jan 2019
              • 116
              • USA

              #7
              Re: intermitted shutdown at high brightness

              Originally posted by budm
              Makes, model, and pictures will help since we have no idea what you have at all.
              Its a sharp lc-c3234u i believe. I learned something new about esr testing. So right now the p board may actually be the problem. Got an esr meter on the way now.

              Comment

              • nomoresonys
                Badcaps Legend
                • Jan 2013
                • 12075
                • U.S.

                #8
                Re: intermitted shutdown at high brightness

                Heat the powerboard with a hairdryer, see if tv stays on longer.

                Comment

                • budm
                  Badcaps Legend
                  • Feb 2010
                  • 40746
                  • USA

                  #9
                  Re: intermitted shutdown at high brightness

                  You need to show us the pictures of the whole backside of the TV showing all the boards, this TV has more than one versions: It has CCFL backlights.
                  https://www.shopjimmy.com/catalogsea...harp+lc-c3234u
                  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

                  • Demonata08
                    Senior Member
                    • Jan 2019
                    • 116
                    • USA

                    #10
                    Re: intermitted shutdown at high brightness

                    Heres the back.

                    Thanks guys.

                    Comment

                    • Demonata08
                      Senior Member
                      • Jan 2019
                      • 116
                      • USA

                      #11
                      Re: intermitted shutdown at high brightness

                      So just a quick update. ive now went through every component on the power board that i can check. the esr meter i got in has shown every capacitor is in excellent condition except the two big ones on the board. They are 220v 470uf but are showing 450uf, .23esr, I do believe thats close enough to the marked value to not cause problems, but since everything else on the board is good im not sure what else it could be.

                      I do notice when its on the main transformer gets remarkably hot. Not like, burn to the touch hot, but still pretty hot.

                      Comment

                      • jetadm123
                        Badcaps Legend
                        • Feb 2010
                        • 2169

                        #12
                        Re: intermitted shutdown at high brightness

                        Sounds like you have a heat related problem. Maybe a bad solder joint? I suggest you do as nomoresonys recommended and heat up each board with a hairdryer to see if you can shorten the shutdown time.

                        Comment

                        • Demonata08
                          Senior Member
                          • Jan 2019
                          • 116
                          • USA

                          #13
                          Re: intermitted shutdown at high brightness

                          Originally posted by jetadm123
                          Sounds like you have a heat related problem. Maybe a bad solder joint? I suggest you do as nomoresonys recommended and heat up each board with a hairdryer to see if you can shorten the shutdown time.
                          I shorted out the error detection on the power supply board to see if it was the LEDs or power supply and so far its been on for about an hour at full brightness. I have no idea what to think about that.

                          Ive been thinking it was either the leds or the power supply board. if i short out the error code it wont turn off when it detects an error so if the leds are bad i can shine a light through the tv and see the picture and if its the power supply i would imagine the whole tv would just power off.(or so thats my thinking)

                          gonna continue to let it run and see what happens.
                          Last edited by Demonata08; 05-10-2019, 11:01 AM.

                          Comment

                          • budm
                            Badcaps Legend
                            • Feb 2010
                            • 40746
                            • USA

                            #14
                            Re: intermitted shutdown at high brightness

                            Your TV dose not use LED for backlights, it uses CCFL for backlights. If one lamp is bad it will shutdown the inverter circuit.
                            Remove the inverter board from the sockets and inspect the sockets and the contact fingers of the inverter board that fit into the sockets.
                            Try turning down backlights level (not Brightness) to see if it will take longer for the backlights to go off. You may have worn backlights, you can also check to see if any one of the Inverter transformer is hotter that the other, check it after the Bcklights go off and TV is unplugged.
                            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

                            • Demonata08
                              Senior Member
                              • Jan 2019
                              • 116
                              • USA

                              #15
                              Re: intermitted shutdown at high brightness

                              Originally posted by budm
                              Your TV dose not use LED for backlights, it uses CCFL for backlights. If one lamp is bad it will shutdown the inverter circuit.
                              Remove the inverter board from the sockets and inspect the sockets and the contact fingers of the inverter board that fit into the sockets.
                              Try turning down backlights level (not Brightness) to see if it will take longer for the backlights to go off. You may have worn backlights, you can also check to see if any one of the Inverter transformer is hotter that the other, check it after the Bcklights go off and TV is unplugged.
                              Yep didnt realize the led thing when i was thinking about it. went back to it and realized afterwards. There wasnt any kind issue with the sockets that i could see. I wasnt sure how to test the inverter transformer and i had already had a power supply from a similar board with the same exact numbered inverters. so i swaped them over carefully and so far its been on for about 4 hours straight at highest backlight. I'm not sure which one of these transformers is bad, i wish i did, because i feel like itd be a good spare part to have around haha.

                              But either way its fixed, hazzah!

                              (EDIT: I shouldnt say its fixed just yet. Im gonna let it run for the rest of the day, But it before it would last around 5 minutes at high backlight so im pretty confident it is fixed )
                              Last edited by Demonata08; 05-10-2019, 05:20 PM.

                              Comment

                              • nomoresonys
                                Badcaps Legend
                                • Jan 2013
                                • 12075
                                • U.S.

                                #16
                                Re: intermitted shutdown at high brightness

                                Was probably just one bad transformer, some model tvs are easier to test transformers than others.

                                Comment

                                • Demonata08
                                  Senior Member
                                  • Jan 2019
                                  • 116
                                  • USA

                                  #17
                                  Re: intermitted shutdown at high brightness

                                  Originally posted by nomoresonys
                                  Was probably just one bad transformer, some model tvs are easier to test transformers than others.
                                  I have a pretty good feeling it was just one. But short of taking turns putting one at a time back in til it errors again is way not worth my time.

                                  This one stayed on for 24 hours straight so i felt comfortable enough selling it. As it turns out the exact same model with the exact same problem has popped up again except this one only stays on for a few seconds(not enough time to adjust the backlight) im gonna crack it open in a few days and hopefully its the same problem.

                                  Comment

                                  • nomoresonys
                                    Badcaps Legend
                                    • Jan 2013
                                    • 12075
                                    • U.S.

                                    #18
                                    Re: intermitted shutdown at high brightness

                                    NAH, I wouldn't do that either, I'd just test each transformer. http://jestineyong.com/test-lcd-inverter-transformer/

                                    Comment

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