LG 42LE4500 No display

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  • tom66
    EVs Rule
    • Apr 2011
    • 32560
    • UK

    #21
    Re: LG 42LE4500 No display

    The voltages, from the main board, should be both 3.3V, or so, as they are. But the LED backlight is not coming on, so something is wrong with the power board. Due to how these sets work, a single LED failure can't cause the whole panel to fail to light.
    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

    Comment

    • dave bro
      New Member
      • Jul 2013
      • 9
      • Ireland

      #22
      Re: LG 42LE4500 No display

      Ok, thanks. Is it possible to get a pdf of the service manual for this tv to maybe narrow the fault down?
      Also, in your opinion considering the age of the tv, is a replacement a better option or a repair?
      Thanks you for your help so far.

      Comment

      • tom66
        EVs Rule
        • Apr 2011
        • 32560
        • UK

        #23
        Re: LG 42LE4500 No display

        Schematics are not available, and I can't see the power board clearly. You can try to repair it yourself by tracing circuits out and replacing parts. Or you can replace the board. I don't think either will be better than the other, except a component level repair will be much cheaper.
        Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
        For service manual, schematic, boardview (board view), datasheet, cad - use our search.

        Comment

        • dave bro
          New Member
          • Jul 2013
          • 9
          • Ireland

          #24
          Re: LG 42LE4500 No display

          Any idea what circuit to start with or the most likely problem circuit?
          Would it help if I tried to post a better picture of the power board?

          Comment

          • tom66
            EVs Rule
            • Apr 2011
            • 32560
            • UK

            #25
            Re: LG 42LE4500 No display

            Try checking diodes, fuses, MOSFETs etc. I don't have enough time to trace a circuit out, so you can only really try the obvious.
            Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
            For service manual, schematic, boardview (board view), datasheet, cad - use our search.

            Comment

            • thuss
              Badcaps Veteran
              • Jul 2012
              • 317
              • uk

              #26
              Re: LG 42LE4500 No display

              Hi

              I have the same tv (42LE4500) which does the same thing.

              I have checked the power supply with the screen working and I get a reading for the pwr 3.33 and Dvr as 12.

              When the screen goes black with the sound still working I get the same readings i. pwr 3.33 and dvr as 12. Should my pwr be 20v? Is my power supply faulty?

              Thanks in advance

              Comment

              • tom66
                EVs Rule
                • Apr 2011
                • 32560
                • UK

                #27
                Re: LG 42LE4500 No display

                Why do you think PWR should be 20V?
                Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                Comment

                • thuss
                  Badcaps Veteran
                  • Jul 2012
                  • 317
                  • uk

                  #28
                  Re: LG 42LE4500 No display

                  Hi

                  I thought looking at the power supply picture next to pwr on (which is in a box) it states 20V?

                  Comment

                  • tom66
                    EVs Rule
                    • Apr 2011
                    • 32560
                    • UK

                    #29
                    Re: LG 42LE4500 No display

                    Probably means the output above or below it is supposed to be 20V, normally PWR (meaning POWER ON) is >2V for on, <0.5V for off.
                    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                    Comment

                    • thuss
                      Badcaps Veteran
                      • Jul 2012
                      • 317
                      • uk

                      #30
                      Re: LG 42LE4500 No display

                      ok thanks

                      Comment

                      • thuss
                        Badcaps Veteran
                        • Jul 2012
                        • 317
                        • uk

                        #31
                        Re: LG 42LE4500 No display

                        Hi

                        Has anyone repaired a 42le4500 power supply?

                        Comment

                        • thuss
                          Badcaps Veteran
                          • Jul 2012
                          • 317
                          • uk

                          #32
                          Re: LG 42LE4500 No display

                          Hi

                          Ive just realised that if I shine a bright light on the 42le4500 whilst in a dark room, I can see the image on the screen. So I assume that the back lights are not working.

                          Has anyone come across this and cured it with a power suppy board change?

                          Comment

                          • scooter13uk
                            New Member
                            • Jan 2014
                            • 3
                            • United Kingdom

                            #33
                            Re: LG 42LE4500 No display

                            Hi,

                            I know this an old post, but did anyone manage to get a fix for TV? Have same problem.

                            Scott.

                            Comment

                            • scooter13uk
                              New Member
                              • Jan 2014
                              • 3
                              • United Kingdom

                              #34
                              Re: LG 42LE4500 No display

                              Manual - http://servicemanuals.pro/serviceman...inish.html?m=0

                              Comment

                              • Maddoga1
                                New Member
                                • Jan 2015
                                • 4
                                • UK

                                #35
                                Re: LG 42LE4500 No display

                                LG 42LE4500 Keeps restarting with a click from the main board

                                My one works fine but turns it self off after about 5 mins and restarts over again and the keep restarting . Does anyone now that I should check first based on this fault

                                Comment

                                • newtothis
                                  Badcaps Legend
                                  • Mar 2013
                                  • 1556
                                  • england

                                  #36
                                  Re: LG 42LE4500 No display

                                  Voltages from PSU?

                                  Comment

                                  • Honacloi
                                    New Member
                                    • Feb 2015
                                    • 3
                                    • UK

                                    #37
                                    Re: LG 42LE4500 No display

                                    Has anyone ever fixed this problem? Was it the PSU?

                                    I have a 42LE4500 that now has a black screen with sound.

                                    In a traditional LCD TV I would just replace the inverter but this set doesn't appear to have one. So does the PSU also act as the inverter in this case?

                                    Comment

                                    • tom66
                                      EVs Rule
                                      • Apr 2011
                                      • 32560
                                      • UK

                                      #38
                                      Re: LG 42LE4500 No display

                                      I've had water damage kill a 37LE4500, the T-con was shorted due to shorted LCD panel.
                                      Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                                      For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                                      Comment

                                      • Honacloi
                                        New Member
                                        • Feb 2015
                                        • 3
                                        • UK

                                        #39
                                        Re: LG 42LE4500 No display

                                        Erm... Thanks Tom. Alas I'm a little puzzled what that has to do with my question. It wasn't caused by water damage.

                                        Comment

                                        • newtothis
                                          Badcaps Legend
                                          • Mar 2013
                                          • 1556
                                          • england

                                          #40
                                          Re: LG 42LE4500 No display

                                          The PSU has the LED driver built in, Its that little green board attached to the PSU.

                                          The PSU's in these sets are prone to failure and are not easy to repair and costly to replace... I have had a few LE models come to me in the last 18 months.

                                          Let me guess... The LG logo comes up then goes off and loses backlighting?... still have an image via flashlight test? If so yes PSU

                                          Comment

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