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    Vizio M60-C3: no picture, backlight works.

    Folks,

    A while ago a dead Vizio M60-C3 had landed in my lap. Its PSU (Vizio: 1P-1151801-1012) was not showing any secondary voltages. I started a separate topic about this problem which I may continue in the future. In the meantime I found a good replacement PSU board, installed it into the TV and turned it on. The white power LED under the bottom left corner lit up, the screen went from black to dark blue, in a couple of seconds dimmed a little and that was it. No picture. The screen would respond to pressing the MENU button on the remote by increasing the brightness slightly but there still was no picture. I also noticed that the right half of the screen (if facing the TV) appeared to be a little darker than the left one. Thinking that some of the RH side LED strips were out, I laid the TV on its face on the bench, took the back cover off and turned off the lights. I could see through the numerous holes in the rear metal panel that all of the backlight LEDs were lit. I dismissed the vision of the darker RH side of the screen as a figment of my imagination and began testing the voltages on the PSU board. All voltages were present as indicated by their respective silkscreen labels except for the T CON_ON (pin 15 of CN201). Evidently the T-Con was not reporting back to the MB so it was probably toast just as the PSU. The MB itself was likely OK.

    Luckily I happened to have the same exact T-Con board in my stash (Vizio: 1P-0142J00-4010, Sharp: RUNTK5556TP) but fortunately I managed to resist the urge to install the T-Con into the TV right away and see if it would start up the TV. And was I glad I did... A quick search on badcaps.net revealed a 32-page thread on the same subject that I read from the first to the last post w/o catching a breath. It read like a novel. Tom66, Budwich, freakaftr8 - you guys are awesome! Daring to rip the side flexes with driver ICs off the LCD panel was one radical move.

    I immediately recalled that one half of the screen of my TV appeared dimmer, and that was probably not a figment of my imagination. It became obvious that my newer 60-inch M-series Vizio was suffering from the same exact dreadful LCD plague as the older 70-inch units. The trouble was, according to freakaftr8 and some other folks posting in different topics, unlike the 70-inch TVs the 60-inch units did not have the side flexes with IC drivers and as such could not be repaired by ripping those flexes out. Wait a minute, sez me to self. Practically all of the cracked LCD screens that I took out while scavenging broken TVs for parts had flex circuits on the side edges. They were not connected to the bottom ones with Mylar bridges, but none the less they were still present. Apparently they were fed through the LCD panel itself, that's all.

    So I took the bezel off the panel and sure enough there they were. Since at that point it had already become rather obvious that the TV was as good as dead because replacing the LCD panel was economically impractical and I had nothing to lose and everything to gain, I decided to peel the side flexes off the glass substrate on the RH side of the TV.

    After I was done with the side flexes but before turning the TV on for the first
    time with a known good T-Con board I disconnected both flat cables for the RH side of the panel from the T-Con board leaving both ones for the LH side of the panel connected to the T-Con. Turned the TV on and the LH side of the screen came to life! Just as freakaftr8 described in that 32-page topic. Amazing.

    Turned the TV off, reconnected the two flat cables that I had disconnected in
    the previous step, turned the TV on again and this time around the full screen lit up. The previously dead TV was working again! I have attached some pix with comments below:

    Image 1. My LCD panel was made by some Chinese company named FOXCONN, not Sharp.
    Image 2. You can see the LH side and the bottom flex circuits.
    Image 3. A close up view of the lower LH corner of the panel.
    Image 4. A different angle for the above view.
    Image 5. A close up view of the lower RH corner of the panel with the flexes already peeled off the glass.
    Image 6. A close up view of the upper RH corner of the panel with the flexes still attached to the glass.
    Image 7. The same view as above but the flexes are already peeled off the glass.
    Images 8-9. A close up view of the 8 RH side flexes. The 2nd IC from bottom on the right appears to be a bit darker than the rest.
    Image 10. Both flat cables for the RH side of the panel are disconnected
    from the T-Con board.
    Image 11. The result of the above.
    Image 12. Both flat cables for the RH side of the panel are reconnected to the T-Con board.
    Image 13. The result of the above.

    So, here's the conclusion for the archives. This brilliant method works not only on the 70- and 80-inch TV sets that have side flexible circuits with horizontal IC drivers connected to the bottom ones via two short connecting flat cables wrapping around the bottom LH and RH side corners of the screen, but it also works on smaller screens as well. The side flexes are also present in those screens and you also need to tear off the offending side in order to fix the no picture problem. The only difference is, with the smaller screen you can't and you don't need to disconnect the side flexes from the bottom ones.

    My most sincere thank you goes to freakaftr8, Tom66, Budwich and a few other folks who came up with this method of repair and/or contributed to the original thread. Without you guys this TV would've been parted out.
    Attached Files
    Last edited by HAHOMETP; 02-20-2017, 09:06 AM.

    #2
    Re: Vizio M60-C3: no picture, backlight works.

    I would like to repair the bad T-Con board that originally came with this TV now that I have two identical boards, one working and one not, side by side. The T-Con model is RUNTK5556TP and there is no COXA transistor anywhere on the board. Nothing seems out of the ordinary and all transistors and diodes check out OK with the diode test on the multimeter, at least in-circuit. Does anyone have any idea where to look? Pix of the bad T-Con are attached.
    Attached Files
    Last edited by HAHOMETP; 02-20-2017, 09:42 AM.

    Comment


      #3
      Re: Vizio M60-C3: no picture, backlight works.

      There are two EEPROMS on the board, IC903 & IC302. Have you tried to read them.
      Willing to help but I'm no expert.

      Comment


        #4
        Re: Vizio M60-C3: no picture, backlight works.

        No, I did not. I don't have an EEPROM reader.

        I suspect that the problem is power related more than anything else. The IC driver(s) on the side flex circuit of the LCD was pulling too much current => this caused the MOSFET Q1, Zener ZD5, the U1 driver for Q1 on the PSU board to blow, and possibly something else too judging by the fact that the original PSU is still not working after replacing these 3 components => and then the problem probably propagated to the T-Con board.

        Comment


          #5
          Re: Vizio M60-C3: no picture, backlight works.

          OK, I've got my 60" Vizio M601d-a3r down to the panel with the bezel off. This particular model has 4 interconnects up each side, I believe the broken IC is the second from the bottom on the left. Do I need to remove all four interconnects, or can I remove only the one that I believe to be broken? If I remove only the broken one but then apply power will that damage the panel? Two sample images attached.
          Attached Files

          Comment


            #6
            Re: Vizio M60-C3: no picture, backlight works.

            all the tabs on the bad side have to be pulled / removed / left clean with no residual material on the contacts.

            Comment


              #7
              Re: Vizio M60-C3: no picture, backlight works.

              Originally posted by budwich View Post
              all the tabs on the bad side have to be pulled / removed / left clean with no residual material on the contacts.
              +1.

              I did a m70i-c3. Same way.
              Did I leave the soldering iron on?

              Comment


                #8
                Re: Vizio M60-C3: no picture, backlight works.

                It's ALIVE!!!!!!!! Removed all four tabs from the broken side and it lives. Thanks for all the trailblazers here that figured out solutions.

                This TV was a bit more difficult to get to the tabs than the 70" models, but the solution works. For posterity, here are the steps:

                1. Snap the plastic black back housing off, there will be a bunch of clips around the edge. I had to get a screwdriver in between the black part and the silver part to disengage the clips.

                2. Detach the IR and power button.

                3. You can then take off the silver plastic housing from the back (8 screws keep it attached).

                4. Be extra careful with this step, you could damage the remaining good IC's if you're rough. Flip the tv onto its back so the panel is facing up (I took the speakers off first, but you can makeshift a jack to do it with the speakers on), you can then remove the bezel after taking out ~15-18 screws or so around the edge.

                5. Remove the four IC's from the bad side.

                6. Reattach the bezel, being extra careful! I actually messed up and one of the tabs on the bezel got between one of the bottom IC's ribbon cable and its board. Definitely had an oh shit moment, but luckily nothing was damaged.

                7. Put everything back together in reverse order.
                Attached Files

                Comment


                  #9
                  Re: Vizio M60-C3: no picture, backlight works.

                  I believe I have the same problem as you with the same TV. Originally would power with no picture and on light would flash 16ish times and nothing. Power board seemed to check out and got a new main board. I now powers with the bluish picture #1 and menu an inputs lighten/darken the screen. Picture #2 white side is with half of the Tcon ribbon cables removed. Same thing with other side. So let me understand you completely remove the perimeter ribbon cables and that fixed it? Also any advice getting to the panel? First TV I've worked on. Thanks for you help.
                  Attached Files

                  Comment


                    #10
                    Re: Vizio M60-C3: no picture, backlight works.

                    @Fredfrederson, I think you need more testing to be sure of the problem, here's a little light reading: https://www.badcaps.net/forum/showthread.php?t=49281
                    Last edited by nomoresonys; 02-27-2021, 05:24 AM.

                    Comment


                      #11
                      Re: Vizio M60-C3: no picture, backlight works.

                      I've tested all main components... Was making sure that my next step was to tear apart and remove the connecting traces. I was asking if you need to remove all the side trace connectors. To achieve the repair.

                      Comment


                        #12
                        Re: Vizio M60-C3: no picture, backlight works.

                        You do, JUST the bad side and of course it's not reversible.

                        Comment


                          #13
                          Re: Vizio M60-C3: no picture, backlight works.

                          .
                          Last edited by nomoresonys; 03-11-2021, 05:24 AM.

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