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LG 60LB5200 will not turn on

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    #21
    Re: LG 60LB5200 will not turn on

    BTW, did you look into as to how much the replacement board is and the replacement IC is?
    You also need to read the spec sheet of that IC and the explanation about how IC function, look at the schematic on page 5 and trace out your board to see how close it is to your board, you need to do some works and study and do the research instead of keep typing "Have I stumped the experts?"
    We are not stumped, we have no schematic of the board, we do not have the board in front of us, we have to do the reverse engineering without having the board in front of us so expert or not it is not easy task and it does not help when we get the wrong data.
    If you want faster service I would suggest you to buy replacement board, you are not the only one asking for free help.
    Do you know how much time I spent to trace out the circuit to find out why you are not getting the VCC but to find out later that DATA was wrong?
    Last edited by budm; 01-18-2018, 11:52 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


      #22
      Re: LG 60LB5200 will not turn on

      My apologies. I have a lot of respect for your knowledge and time.

      I originally was just wanting to confirm that it was the power supply that was at fault. Then you and maxvalutech started offering troubleshooting tips. So, I figured I would just go the route of trying to fix it with your guidance.

      I have looked for a replacement board with no luck. Every website that I have found shows out of stock and no expected replacement stock.
      Last edited by WTRWLKR; 01-18-2018, 01:06 PM.

      Comment


        #23
        Re: LG 60LB5200 will not turn on

        Not knowing enough about how this works, is the power supply in an always on state or does it wait for a signal on EN, to activate the power supply?

        Comment


          #24
          Re: LG 60LB5200 will not turn on

          having similar issue. plugged in the tv constantly has the green LED on but it is slightly flickering(no Pic on TV). tv will not turn off(red LED). when I took off the back panel all components look fine (nothing burnt/swollen that I can see). when I remove the connector from the pwr supply and apply pwr I'm getting all the 24v and 12v but cant get the 5v standby. once I plug all the cards back into the pwr supply the main board starts making a slight clicking noise and the pwr supplys 24v and 12v drop to 12v and 6v (half voltage)

          Comment


            #25
            Re: LG 60LB5200 will not turn on

            Originally posted by kyle37095 View Post
            having similar issue. plugged in the tv constantly has the green LED on but it is slightly flickering(no Pic on TV). tv will not turn off(red LED). when I took off the back panel all components look fine (nothing burnt/swollen that I can see). when I remove the connector from the pwr supply and apply pwr I'm getting all the 24v and 12v but cant get the 5v standby. once I plug all the cards back into the pwr supply the main board starts making a slight clicking noise and the pwr supplys 24v and 12v drop to 12v and 6v (half voltage)
            Are you sure you do not have 5V standby? The 24V and 12V power supply will not work without the standby power supply running because the standby power supply provides the VCC to run the SMPS IC for the 12V/24V power supply.
            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


              #26
              Re: LG 60LB5200 will not turn on

              I measured from connector point en to case gnd and didn't get anything.

              Comment


                #27
                Re: LG 60LB5200 will not turn on

                Please upload good clear pictures of YOUR board, I need to see that pin.
                https://www.badcaps.net/forum/attach...0&d=1513110658
                The board of OP in POST one does not have STANDBY pin, it is an always on power supply with only one transformer without standby power supply transformer.
                Last edited by budm; 04-11-2018, 09:34 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


                  #28
                  Re: LG 60LB5200 will not turn on

                  Mine is exactly the same tv and pwr supply

                  Comment


                    #29
                    Re: LG 60LB5200 will not turn on

                    "but cant get the 5v standby"
                    If it is the same board then I do not see 5V STANDBY pin, where is it?
                    The connector has 12V, 24V, EN, and GND.
                    EN = PS-ON which is the command signal from main board, it should change state when power switch is toggled on and off.

                    " once I plug all the cards back into the pwr supply the main board starts making a slight clicking noise and the pwr supplys 24v and 12v drop to 12v and 6v (half voltage)"
                    That means the power supply is weak due to problem or the main board is drawing too much current which causes the power supply to go into shutdown/startup cycle.
                    Last edited by budm; 04-11-2018, 10:38 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


                      #30
                      Re: LG 60LB5200 will not turn on

                      ok then this one does not have a standby then.. good to know!. how can I troubleshoot to see what board is the issue? I would rather spend 100$ on 1 board than 200$ on 2 separate boards.

                      Comment


                        #31
                        Re: LG 60LB5200 will not turn on

                        The key point is when all the boards are connected together do you see the DC Voltage ON the EN pin change state when power switch is toggled.
                        The power supply does have standby Voltage, 12V (isntead of typical 3.3V or 5V), when PS-ON is present then the 24V power supply is turned on.
                        As I indicated in post 39:

                        " once I plug all the cards back into the pwr supply the main board starts making a slight clicking noise and the pwr supplys 24v and 12v drop to 12v and 6v (half voltage)"
                        That means the power supply is weak due to problem or the main board is drawing too much current which causes the power supply to go into shutdown/startup cycle.
                        You can test the power supply board by forcing it on and use dummy load on the 12V and the 24V to pull the rated current of the power supply to see if it can handle the load or not.
                        Last edited by budm; 04-11-2018, 01:30 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


                          #32
                          Re: LG 60LB5200 will not turn on

                          budm just a general question can car 12v bulbs be used to load test a psu as most people have these handy will they draw enough current?

                          Comment


                            #33
                            Re: LG 60LB5200 will not turn on

                            En vdc is 2.5v no matter what. 24v pwr supply output is 15v constant and 12output is at 6v constant. Main board is still making a very quiet pew pew sound. Green led light on the bottom of the tv is still constantly lightly flickering

                            Comment


                              #34
                              Re: LG 60LB5200 will not turn on

                              OK, let me get this straight, if you run the power supply board by itself without having the main board connected, the 24V and the 12V power supply is steady, if it is then you need to check the DC Voltage between the two legs of the main filter cap to see if you have about 380 ~ 400VDC or not, the OP's board has problem with PFC Voltage booster section.
                              Be real careful because you are making the measurement in the HOT DEADLY side of the circuit.
                              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


                                #35
                                Re: LG 60LB5200 will not turn on

                                Originally posted by vinceroger69 View Post
                                budm just a general question can car 12v bulbs be used to load test a psu as most people have these handy will they draw enough current?
                                It depends on how sensitive the over current shutdown circuit is because the Cold resistance of incandescent lamp is very low so the power supply will see very high surge current.
                                The cold resistance of the incandescent lamp is about 15 times lower than the hot resistance. I.E. 12V 12Watts lamp has hot resistance of 12 Ohms (1A of current) that means the cold resistance will be <1 Ohm so the current will be very high (>12A) for short period of time when 12V is first applied.
                                You can easily check the cold resistance of the lamp with Ohm meter.
                                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


                                  #36
                                  Re: LG 60LB5200 will not turn on

                                  450vdc caps are reading 167vdc. I unplugged all the cards north of the pwr supply. Still out putting 16v for 24 v pins. That is new it was outputting 24v on 24v pin?

                                  Comment


                                    #37
                                    Re: LG 60LB5200 will not turn on

                                    Originally posted by kyle37095 View Post
                                    450vdc caps are reading 167vdc. I unplugged all the cards north of the pwr supply. Still out putting 16v for 24 v pins. That is new it was outputting 24v on 24v pin?
                                    Is this reading of 167V with the EN pin at >2V DC? If EN signal is not present then the PFC will not work same for the rest of the switched power supply section.
                                    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


                                      #38
                                      Re: LG 60LB5200 will not turn on

                                      Took the card off the tv and something sounds like it has sand in it but I can't tell what component it is

                                      Comment


                                        #39
                                        Re: LG 60LB5200 will not turn on

                                        Even with everything plugged it it's still at 167vdc

                                        Comment


                                          #40
                                          Re: LG 60LB5200 will not turn on

                                          Did you ever resolve this? I have the same model and get the same readings. I swapped out the main board with no luck. No one has a power supply board in stock, so I can't try that.
                                          I know how to use a multimeter and solder electronics but no diagnostic ability. The tv is only a few years old and I don't want to have to buy another.
                                          This was our everyday tv that sat in our dining room for a month while we remodeled. Plugged it in and all I get is the flickering green light.
                                          I appreciate any and all help.

                                          Comment

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