LG 42LW4500-LB Need help with repair of PSU

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  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #41
    Re: LG 42LW4500-LB Need help with repair of PSU

    Originally posted by UndeadLuke
    Where I can found the power switch ? It will be good if you have some scheme for this board .
    Do you mean all these time you do not know where the power switch is? So how in the world you know that the relay is working?
    How about going to LG website and down load the user manual?
    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

    • UndeadLuke
      Member
      • Nov 2016
      • 25
      • Czech Republic

      #42
      Re: LG 42LW4500-LB Need help with repair of PSU

      Originally posted by budm
      Do you mean all these time you do not know where the power switch is? So how in the world you know that the relay is working?
      How about going to LG website and down load the user manual?
      So you telling me i need to coonect the man
      Inboard and everything else and try to pit on 230vac try to set on tv and after thst i need to look for bad part ? I will try to remove the surge protection and i will check the board under voltage again if the voltage will go after because now i have voltage only on main gray filter cap i will replace the surge protection with cable for test

      Comment

      • UndeadLuke
        Member
        • Nov 2016
        • 25
        • Czech Republic

        #43
        Re: LG 42LW4500-LB Need help with repair of PSU

        Originally posted by budm
        Do you mean all these time you do not know where the power switch is? So how in the world you know that the relay is working?
        How about going to LG website and down load the user manual?
        I need service manual for board scheme :/

        Comment

        • syaoran123
          Senior Member
          • Jun 2014
          • 178
          • Australia

          #44
          Re: LG 42LW4500-LB Need help with repair of PSU

          The mainboard is a common fault. Just saying its a possibility. All you need is to to heat up the large heatsink with a hair-dryer on highest heat for 2 minutes and turn on. Let me know if it doesnt work, then we can move on to psu

          Comment

          • budm
            Badcaps Legend
            • Feb 2010
            • 40746
            • USA

            #45
            Re: LG 42LW4500-LB Need help with repair of PSU

            So far I asked you to provide simple DCV reading of the PWR-ON pin on post 26 but insisting on replacing the MOV. WHY? THE DAM THING IS NOT BAD! GET IT!
            I WASTED MY TIME ON THIS THREAD WHEN YOU CANNOT EVEN FOLLOW THE INSTRUCTION!
            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

            • syaoran123
              Senior Member
              • Jun 2014
              • 178
              • Australia

              #46
              Re: LG 42LW4500-LB Need help with repair of PSU

              Originally posted by budm
              So far I asked you to provide simple DCV reading of the PWR-ON pin on post 26 but insisting on replacing the MOV. WHY? THE DAM THING IS NOT BAD! GET IT!
              I WASTED MY TIME ON THIS THREAD WHEN YOU CANNOT EVEN FOLLOW THE INSTRUCTION!
              Someone needs a chill pill

              Comment

              • budm
                Badcaps Legend
                • Feb 2010
                • 40746
                • USA

                #47
                Re: LG 42LW4500-LB Need help with repair of PSU

                Originally posted by syaoran123
                Someone needs a chill pill
                Well what do you think?
                Post 39: "Where I can found the power switch ? It will be good if you have some scheme for this board ."
                Post 42 "I will try to remove the surge protection" still try to deal with MOV after all the explanation?
                We are over 40 posts now an still no answer on the PWR-ON signal pin. If there is no PWR-ON form main board then the Main board will have to be checked, but at this we do not know if we have that signal or not. May be after he finds the Power switch?
                Last edited by budm; 11-29-2016, 10:40 AM.
                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

                • UndeadLuke
                  Member
                  • Nov 2016
                  • 25
                  • Czech Republic

                  #48
                  Re: LG 42LW4500-LB Need help with repair of PSU

                  Originally posted by budm
                  Well what do you think?
                  Post 39: "Where I can found the power switch ? It will be good if you have some scheme for this board ."
                  Post 42 "I will try to remove the surge protection" still try to deal with MOV after all the explanation?
                  We are over 40 posts now an still no answer on the PWR-ON signal pin. If there is no PWR-ON form main board then the Main board will have to be checked, but at this we do not know if we have that signal or not. May be after he finds the Power switch?
                  I just remove the surge protection and TV starts LCD shine i also hear click of rele so maybe i will try to do this with this surge protection again .. and chill man I know Iam dumbass maybe but i made progress and it starts shine before it do nothing just turn off imidietly

                  Comment

                  • budm
                    Badcaps Legend
                    • Feb 2010
                    • 40746
                    • USA

                    #49
                    Re: LG 42LW4500-LB Need help with repair of PSU

                    Well, you are not making any sense since as explained, the MOV is connected in parallel with the cap which you have measured 230VAC between the cap's legs, the MOV has nothing to do with the TV functioning, more likely you have disturbed bad connections or connectors that may not be seated properly or loose mounting screws holding the board to make the GND connection to the chassis, etc..
                    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

                    • Andrew F. Ali
                      Badcaps Legend
                      • Jan 2014
                      • 2450
                      • Trinidad & Tobago

                      #50
                      Re: LG 42LW4500-LB Need help with repair of PSU

                      I really think this person is toying with our good intention....Sometimes not all threads are real.....I detect a mischief maker here.....Just can't follow a simple instruction...then go and do something that makes no sense and ...voila...it comes ON....Sheeeeesh....Anyway budm....you certainly have the virtue of patience....I would have given up a long time ago.....just reading this post makes my head ache......Thanks.

                      Comment

                      • vahid114
                        New Member
                        • Jan 2018
                        • 6
                        • iran

                        #51
                        Re: LG 42LW4500-LB Need help with repair of PSU

                        Hi, please help me to find the r123 resistance number on the power board LG 47lw4500

                        Comment

                        • happyade123
                          Senior Member
                          • Feb 2015
                          • 92
                          • Australia

                          #52
                          Re: LG 42LW4500-LB Need help with repair of PSU

                          Is this guy for real. No offence . Mate you have been given some very clear instructions and only measuring low voltage instead you are opting to measure the higher more dangerous voltages. Personally I think you would be better off putting the cover back on and take it to someone who knows at least where the power switch is and how to do basic troubleshooting. Just because the power supply is on one board does not mean it automatically runs all the time. It requires other voltages and signals from other boards to allow all the different, voltage rails to turn on. Bud M has given you excellent advice. Measure the PS on voltage between ground and the ps on pin of power supply. If you don't feel confident just hook up Jumper clips to ground and a component off the ps on pin. Put your metre on dc not ac. Do you have a picture of your metre? Willing to help more but not if there is a risk of endangering your life. Even your electrotechnical teacher (as you put it) would dissuade you from touching it , unless of course this is some kind of joke , then you are just wasting people's time.

                          Comment

                          • WTRWLKR
                            Member
                            • Dec 2017
                            • 24
                            • USA

                            #53
                            Re: LG 42LW4500-LB Need help with repair of PSU

                            Hi vahid114,

                            You may want to start a new thread. This one died over a year ago.

                            Comment

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