Sharp LC-70LE757U TV not working (2-5 signal)

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  • EthanButz
    Member
    • Jan 2018
    • 11
    • United States

    #1

    Sharp LC-70LE757U TV not working (2-5 signal)

    I've been looking around these fora since I have an LC-70LE757U Sharp flatscreen TV and it has the same problem as many other cases but not exactly the same. When you plug it in, the Sharp symbol on the bottom flashes the 2 long and 5 short signals that something is wrong with the T-Com board. I found this attached support letter which helped somewhat. The T-Com has four ribbons attached to it and, with all of them unplugged, the backlight comes on. With one plugged in, there are some lines down the display on the left. With two plugged in just backlight. With three plugged in, the two inner ribbons and the left or right ribbon, the left and right sides respectively work. I tried resetting it by holding the input and volume down buttons while plugging it in and it just started normally. I can buy the T-Com board for $80 on eBay but I've heard that it's been replaced before with no success. Anything else that I should test? Thanks for the help
    Attached Files
  • budwich
    Badcaps Legend
    • Jul 2015
    • 3097
    • Canada

    #2
    Re: Sharp LC-70LE757U TV not working (2-5 signal)

    Its unlikely that its a tcon issue. More likely that you have a panel problem. Lots of thread for this type of set. Basically, you need to leave all cabling in place on the tcon. At the bottom corner of the panel (at each side), there is a small ribbon cable which interconnects the bottom edge boards to the side edge boards. Disconnect this cable (either end) and check the resulting display. Repeat the test doing the same for the other side. Post pictures of the results and you can go from there.

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    • EthanButz
      Member
      • Jan 2018
      • 11
      • United States

      #3
      Re: Sharp LC-70LE757U TV not working (2-5 signal)

      With all four main ribbons plugged in and the ribbons in the bottom left and right corners the screen had backlight and only displayed color when it started up and when I pressed the menu button (as seen in picture)
      Attached Files

      Comment

      • budwich
        Badcaps Legend
        • Jul 2015
        • 3097
        • Canada

        #4
        Re: Sharp LC-70LE757U TV not working (2-5 signal)

        Please reread what I said and follow the test that I suggest.... I don't understand your "the ribbons in the bottom left and right corners" ????? what does this mean?

        Comment

        • EthanButz
          Member
          • Jan 2018
          • 11
          • United States

          #5
          Re: Sharp LC-70LE757U TV not working (2-5 signal)

          You said to disconnect the ribbon cables in the corners of the panel which I did. There is a small ribbon connector in the bottom left corner and one in the bottom right corner of the panel that I disconnected from the side edge boards on either side. When I disconnected both of those ribbon cables but kept the four ribbon cables connecting to the T-Com to the bottom edge plugged in this is what happened to the screen. I had backlight unlike when the two smaller ribbon cables are connected but anything that the screen displays shows up as multicolored lines.

          Comment

          • EthanButz
            Member
            • Jan 2018
            • 11
            • United States

            #6
            Re: Sharp LC-70LE757U TV not working (2-5 signal)

            If the left ribbon is plugged into the left side-edge pannel (but not the right one) there is full display but the colors are not correct.

            Sorry if I misunderstood, still getting used to TV and electronic jargon
            Attached Files
            Last edited by EthanButz; 01-03-2018, 02:20 PM.

            Comment

            • budwich
              Badcaps Legend
              • Jul 2015
              • 3097
              • Canada

              #7
              Re: Sharp LC-70LE757U TV not working (2-5 signal)

              we have a bit of a "communication problem". :-) I didn't say to disconnect BOTH of the corner cables at the same time.... if you read that in to it... then how would you do the "repeat the test for the other side". Anyways, it doesn't matter as it appears eventually, you did have only one corner disconnected. The pictures that you posted show you have a panel error with one of the tabs on the side.... that's the horizontal line that you see.

              Comment

              • EthanButz
                Member
                • Jan 2018
                • 11
                • United States

                #8
                Re: Sharp LC-70LE757U TV not working (2-5 signal)

                So what is my solution?

                Comment

                • budwich
                  Badcaps Legend
                  • Jul 2015
                  • 3097
                  • Canada

                  #9
                  Re: Sharp LC-70LE757U TV not working (2-5 signal)

                  Originally posted by EthanButz
                  If the left ribbon is plugged into the left side-edge pannel (but not the right one) there is full display but the colors are not correct.

                  Sorry if I misunderstood, still getting used to TV and electronic jargon
                  what the result with the "other way around"?

                  Comment

                  • EthanButz
                    Member
                    • Jan 2018
                    • 11
                    • United States

                    #10
                    Re: Sharp LC-70LE757U TV not working (2-5 signal)

                    Absolutely nothing, not even a backlight.

                    Comment

                    • budwich
                      Badcaps Legend
                      • Jul 2015
                      • 3097
                      • Canada

                      #11
                      Re: Sharp LC-70LE757U TV not working (2-5 signal)

                      That indicates that side that remains connected is bad and the set can't create a "picture" using it. Your first "test" used the "good side" with the "bad side" disconnected and thus could cause a picture since the "bad side" was now removed... confused yet... :-)

                      Anyways, the tv can't be fixed, it can only be saved... that is, the tabs along the bad side are removed. The result is an "perfect picture" ... "perfect" in terms of general watching but a "discerning viewer" may notice some issues since the screen is being driven by only one side of electronics.... hence the "save". There are lots of posts on the "success" of this "technique" to get a working set. Search the forum and you will find many. One note: once the tabs are removed, they can never be put back (its a one way street), hence you need to be certain that you are removing the bad side and further that you have no other recourse (ie. warranty or otherwise).

                      Still further, your comment about the "left ribbon plugged in, right one not" gave you the pictures that you posted... doesn't quite jive....again somewhere we are "miscommunicating"... the pictures show the horizontal line coming from the left and fading / disappearing on the right. This is likely not possible in my opinion.... of course, you are possibly referring to the "left and right" positions from the back of the set.... my guess. You need to be very certain of your word references otherwise we may "miscommunicate" again and it might result in you removing the WRONG tabs. :-(

                      Comment

                      • EthanButz
                        Member
                        • Jan 2018
                        • 11
                        • United States

                        #12
                        Re: Sharp LC-70LE757U TV not working (2-5 signal)

                        If I remove the bad side will the picture quality improve or will it stay the same as it is in the pictures I sent?

                        Comment

                        • mmartell
                          Badcaps Legend
                          • Oct 2013
                          • 3189
                          • Canada

                          #13
                          Re: Sharp LC-70LE757U TV not working (2-5 signal)

                          If you remove the ribbons on the bad side the picture will return to normal. As budwich stated there are many threads on this already do some reading so you can get up to speed on what needs to be done and why.

                          Comment

                          • EthanButz
                            Member
                            • Jan 2018
                            • 11
                            • United States

                            #14
                            Re: Sharp LC-70LE757U TV not working (2-5 signal)

                            So I've taken off the bezel of the TV and I can access the bad side panel for the display that was NOT working when tested. There are five ribbon cables (not detachable) that go from the edge panels to the LCD display. I have pictures of what I have so far. You're saying that if I detach these five cables from the LCD then the screen should "work" again? If so how do I detach them correctly, I've been looking for hours and I can't find a solution.
                            Attached Files

                            Comment

                            • budwich
                              Badcaps Legend
                              • Jul 2015
                              • 3097
                              • Canada

                              #15
                              Re: Sharp LC-70LE757U TV not working (2-5 signal)

                              basically you just tear them away like pulling tape off something. You need to ensure that the contacts there after are clean / clear of any remnants there after. The side edge boards can then be unclipped from the holders and removed as they are useless thereafter.

                              Comment

                              • Fletch2
                                New Member
                                • Jul 2018
                                • 1
                                • Canada

                                #16
                                Re: Sharp LC-70LE757U TV not working (2-5 signal)

                                Just fixed my LC-70LE757U last night. Although in Spanish, great YouTube video here that helped me: https://youtu.be/xXNTKYDLD5M

                                Comment

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