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Sharp LC-60LE741E - Horizontal Bands / Stripes

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    Sharp LC-60LE741E - Horizontal Bands / Stripes

    I have a strange problem that appeared suddenly on my SHARP LC-60LE741E 60” LCD television. It has 22 evenly spaced horizontal grey stripes over the entire area of the screen. The stripes only effect dim areas of an image. Blacks are still purely black, and anything brighter than 40% is unaffected. Bright outdoor scenes are fabulous. Dark low contrast scenes ... like all CGI on Netflix are unbearable. It's like your looking through dirty venetian blinds. The grey bars appear above any slightly dark colors. If you look closely, you'll see that there are white pixels mixed in with the correct colors over the width and height of the bars. The edges of the bars are sharp. Between the grey bars, the image in un-effected. From close up, it looks like the TV is adding black pixels to the color to darken it, but inside the bars, the black pixels are turning white.

    At the same time as the TV started to do this, it also started to exhibit image retention. If anything bright stays on the screen for more than a few seconds, like a brightly lit window, or a logo, or text, it will stay there on the screen, slowly fading for about 20 seconds until its gone. For 20 seconds after text disappears from the signal, I can continue to read it perfectly on the screen until it fades away.

    It has nothing to do with the LCD panel. Motion is still perfect. The LCD layer is fully responsive. Bright images are spectacular. Blacks are pure black.

    In the sample image, you can see the horizontal bars as well as the white area, text and logo that was on the screen 10 seconds before I took the picture. A while later, these all faded away.

    Anyone have any suggestions?
    Attached Files
    Last edited by Strudul; 12-20-2022, 06:58 PM.

    #2
    Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

    wonder if its a tcon issue.
    Quit due to disrespect from unpaid sta,ff.

    Comment


      #3
      Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

      Originally posted by nomoresonys View Post
      wonder if its a tcon issue.
      Thanks for the response. Is there a reason you say tcon over main board?

      Comment


        #4
        Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

        I think I have seen these symptoms more with tcons than mainboards but its a guess til testing proves it out.
        Quit due to disrespect from unpaid sta,ff.

        Comment


          #5
          Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

          Originally posted by nomoresonys View Post
          I think I have seen these symptoms more with tcons than mainboards but its a guess til testing proves it out.
          Not something that can be diagnosed with a multimeter easily I take it, just an iffy chip?
          Attached Files
          Last edited by Strudul; 12-21-2022, 11:12 AM.

          Comment


            #6
            Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

            can you post a good clear picture of each board, maybe remove cover from tcon if there is one, and one of the whole back, as to see how everything is connected.
            Quit due to disrespect from unpaid sta,ff.

            Comment


              #7
              Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

              Originally posted by nomoresonys View Post
              can you post a good clear picture of each board, maybe remove cover from tcon if there is one, and one of the whole back, as to see how everything is connected.
              Are these clear enough?
              Attached Files
              Last edited by Strudul; 12-21-2022, 12:04 PM.

              Comment


                #8
                Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                try heating up the tcon board with a hairdryer for a couple minutes, heat the whole thing chips caps and all for a couple minutes, then try the tv, see if there's any difference, DON'T let it cool back down try it while its still hot.
                Quit due to disrespect from unpaid sta,ff.

                Comment


                  #9
                  Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                  Originally posted by nomoresonys View Post
                  try heating up the tcon board with a hairdryer for a couple minutes, heat the whole thing chips caps and all for a couple minutes, then try the tv, see if there's any difference, DON'T let it cool back down try it while its still hot.
                  Would it be easier to heat it while it's already on?

                  Comment


                    #10
                    Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                    guess you could but it isn't usually done that way.
                    Quit due to disrespect from unpaid sta,ff.

                    Comment


                      #11
                      Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                      Originally posted by nomoresonys View Post
                      guess you could but it isn't usually done that way.
                      Well that was exciting.

                      Connected everything back up, and turned it on to make sure it still worked and displayed the same symptoms.

                      Left it on and wafted my heatgun over the board for a minute. Checked the picture and noticed the horizontal bands seemed to have reduced in size and were moving about a bit.

                      Hit it with the heatgun for another couple minutes and it seemed to resolve the issue completely.

                      However, after leaving it for a few minutes, the horizontal bands have returned.

                      At least that proves it's the tcon board, but does that reappearance of symptoms on cooldown imply it's just dry joints and it needs a more intense application of heat to reflow the solder or something else?

                      Comment


                        #12
                        Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                        Well you could try the reflow route, not much to lose, may be able to pinpoint the faulty component with selective heating. I usually just replace the tcon, they should be pretty reasonable, can always mess around testing everything and maybe find the problem but I don't bother for the cheaper boards.
                        Last edited by nomoresonys; 12-21-2022, 01:05 PM.
                        Quit due to disrespect from unpaid sta,ff.

                        Comment


                          #13
                          Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                          Originally posted by nomoresonys View Post
                          I usually just replace the tcon, they should be pretty reasonable, you can fool around testing everything and maybe find the problem but I don't bother for the cheaper boards.
                          I can't seem to find any available at the moment, but will keep an eye out.

                          Out of interest I tried just applying heat to just the right side of the board on / around the large chip and that temporarily resolved the issue again.

                          Thanks for the assistance. Much appreciated.

                          Comment


                            #14
                            Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                            If it's the large chip with legs, you can touch it up with a soldering iron, if it's the memory chip of the chip in the middle it's BGA and requires reflowing with hotter temperatures and flux.

                            Comment


                              #15
                              Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                              Originally posted by diif View Post
                              If it's the large chip with legs, you can touch it up with a soldering iron, if it's the memory chip of the chip in the middle it's BGA and requires reflowing with hotter temperatures and flux.
                              Yeh, seems to be the larger TQFP.

                              Would you need to dab each leg separately with a soldering iron to avoid the solder bridging across the legs, or should it just transfer the heat and everything stay in place?

                              Comment


                                #16
                                Re: Sharp LC-60LE741E - Horizontal Bands / Stripes

                                I'd find the not soldered leg(s) and just touch that up with a bit more solder.

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