LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

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  • blair
    New Member
    • Jan 2013
    • 3
    • Canada
    #1

    LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

    Hi there,

    I just recently bought a used TV from my friend for $80, he let me know that there was some sort of power problem with it, it would work alright for a while then just randomly turn off, and then not turn on for a long while.

    When you press the remote power button (or the TV power button), it does the red blinks like it warming up/turning on, then goes to the blue (means its on), however no sound or picture comes up on the screen.

    It worked great all day the first day I had it, and now it won't even turn on at all. I was told that sometimes it just stays off for a day or two so we will see if it will turn on tomorrow, however, this must be fixed.

    I have done some research on what the issue may be, I have come across alot of information and I am not very experienced with TV/monitor-related repair, however I am well experienced in computers, software and hardware, and I am planning on doing the repairs myself rather then taking it into a shop.

    I was reading that it might be a capacitor on the power board, so I opened up the back of the TV and none of them are blown up, exploded, or bulging from what I can tell. However, I am planning on replacing all of them on the power board anyway, so I was wondering if anyone knew where I can get affordable ones for my board? I live in Canada so they would have to be able to ship to Canada.

    If the capacitor repair does not work, my next option would be to completely replace the power board.. this is just what from what I've read online and I will have one of my friends take a look at it tomorrow.

    If you've read all the way down to here I really appreciate it and please give me some input on this problem!

    Thanks
    Tags: None
    • retiredcaps
      Badcaps Legend
      • Apr 2010
      • 9271
      #2
      Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

      Originally posted by blair
      However, I am planning on replacing all of them on the power board anyway, so I was wondering if anyone knew where I can get affordable ones for my board? I live in Canada so they would have to be able to ship to Canada.
      Digikey.ca is well respected and has great service. Shipping will cost $8, but you get it quite quickly.

      However, before you order anything, check to see if the power board has 5V DC standby.
      --- begin sig file ---

      If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

      We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

      Please do not post inline and offsite as they slow down the loading of pages.

      --- end sig file ---

        Comment

        • blair
          New Member
          • Jan 2013
          • 3
          • Canada
          #3
          Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

          The only power boards I found for my model were on ebay and some 'parts something' (forget the name) website... I was just going to make sure the part # matched the one in my TV.

          I am confused on what you mean by 5V DC standby...? Would this be something related to the caps I can put on the board?

            Comment

            • Dgtech
              E. Technician
              • Apr 2009
              • 1462
              • Steeler
              #4
              Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

              Post clear pictures of your boards.
              The strong-minded rise to the challenge of their goals,the weak-minded BECOME HATERS

                Comment

                • blair
                  New Member
                  • Jan 2013
                  • 3
                  • Canada
                  #5
                  Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

                  Working on the pictures, don't have a good camera so I will have to borrow my buddies and I will let you know.

                  How easy is it to kill a component via static electricity? Mainly TV components?

                  I'm going to stop by a store and see if I can pick up a multimeter or something like that...

                    Comment

                    • tom66
                      EVs Rule
                      • Apr 2011
                      • 32560
                      • UK
                      #6
                      Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

                      Touching the metal frame of the TV occasionally during service is sufficient to prevent static damage in the vast majority of cases.
                      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

                        • MisterD
                          Badcaps Veteran
                          • Oct 2012
                          • 668
                          • United States
                          #7
                          Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

                          To answer your question about 5V DC Standby Check this out, it may be of help to you.
                          Attached Files

                            Comment

                            • retiredcaps
                              Badcaps Legend
                              • Apr 2010
                              • 9271
                              #8
                              Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

                              Originally posted by MisterD
                              To answer your question about 5V DC Standby Check this out, it may be of help to you.
                              Note: This is not aimed at blair, but after seeing budm get frustrated again, I thought I would add some suggestions.

                              I think if budm changed his sig file to include a link to his guide, he wouldn't be so burnt out answering questions. At a minimum people asking for help should read through it completely and ask clarification questions.

                              This approach is more

                              "Give a man a fish and you feed him for one day.
                              Teach a man how to fish and you feed him for life.

                              This approaches scales. Giving one on one help burns out many regulars (including myself).

                              It is also why I changed my sig file to give clear examples of what we need in terms of picture clarity and composition, information, etc. If people don't bother to read it, I will reciprocate.

                              Not everyone agrees with my approach and I have been called condescending with this method, but I refuse to answer anymore "how do I test a fuse" questions after I have written about it countless times.
                              Last edited by retiredcaps; 01-23-2013, 01:34 AM.
                              --- begin sig file ---

                              If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

                              We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

                              Please do not post inline and offsite as they slow down the loading of pages.

                              --- end sig file ---

                                Comment

                                • budm
                                  Badcaps Legend
                                  • Feb 2010
                                  • 40746
                                  • USA
                                  #9
                                  Re: LG 42LG70 42" LCD 1080p - Won't turn on/no picture&sound

                                  Thanks retiredcaps, I juat add the link.
                                  Last edited by budm; 01-23-2013, 11:30 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

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