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Can you dignose from the photo ? . Toshiba 65S2650EV

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    #81
    Re: Can you dignose from the photo ? . Toshiba 65S2650EV

    We are in business.
    I disconnect the bypass and TV works as before.

    Now I will go by the VGL TPs nearest to the IC. 6 TPs in 3 pairs, at one of them comes VGH , so I will measure and see which TP doesn't have V .

    But. Since I don't think I made a mistake with the bypass, and the situation is worse visually, What or Where would the problem be ?

    Comment


      #82
      Re: Can you dignose from the photo ? . Toshiba 65S2650EV

      OK . Measured and I soldered correctly .
      All TP in duo test -7.7V , only the one TP not - and I soldered there.

      This TP measures now ~4V , which is NEW, since earlier I measured 18V

      Any ideas what next ?
      Attached Files
      Last edited by Ancient1; 12-13-2021, 04:38 AM.

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        #83
        Re: Can you dignose from the photo ? . Toshiba 65S2650EV

        now I'm outside for work.. two possible causes, one the cof is faulty and holds inside a short, two when you handled to separe the soldering short you have broke the track that carries vgh to the cof, after soldering you must measure 27v, 4v means two things, vgh supply is in protection due to shorted cof, or something bad in soldering, enameled wire must be scratched before soldering, further with cof active, vgh must be present also on the output tp...

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          #84
          Re: Can you dignose from the photo ? . Toshiba 65S2650EV

          I have a horizontal line (2 near each other) few cm above the TAB - I thought to deal with it later, but : could it be related ?

          VGH on PCB is fine : ~26.7V
          I will investigate VGH on input and output TP later
          Last edited by Ancient1; 12-13-2021, 11:03 AM.

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            #85
            Re: Can you dignose from the photo ? . Toshiba 65S2650EV

            The line can indicate a short inside cof, no, it's almost sure, at least on its outputs of the 2 lines.. i don't know how much affects the rest..

            Comment


              #86
              Re: Can you dignose from the photo ? . Toshiba 65S2650EV

              My plan for today :
              • Locate the line on screen and maybe measure V on all TPs ( too many needle points - measurements - on those TPs )
              • take the panel out and put on table
              • measure continuity of my bypass , and the TP to others nearby, especially to the exit/output VGH TP.
              • Investigate the line : COF continuity on VGH VS the next COF

              Comment


                #87
                Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                with some approximation it is possible to insulate the load (i.e. the panel) from the 2 faulty linee, this can improve things, but this is another story... if you will not find a solution, last solution will be remove the faulty tab..

                Comment


                  #88
                  Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                  can you explain : which "2 faulty lines" .

                  What I am going to do now is to survey the situation, so we can understand better.
                  Any suggestions ?


                  * VGH on the TAB is now 5V : on In and Out TPs
                  * Those grayscale faint areas/borders are present
                  * As you can see : the [No Input] box is has decay issue on left side, it moves cleanly on right side
                  * The Faulty Line is halfway between the first and second Tabs

                  What all this means as to where the problem/s is I have no idea.

                  I will now take the panel out and look for physical ( mostly) issues
                  Attached Files
                  Last edited by Ancient1; 12-14-2021, 02:39 AM.

                  Comment


                    #89
                    Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                    OK
                    So I worked 3 Hrs , with x25 magnification, continuity measurement ..
                    Cleaned the solder very well
                    In the photo : in blue are TPs with continuity. But the VGH was fine
                    I covered in ultraviolet lacque and soldered .

                    No Joy : Left side white on Flex disconnect, or No logo if both connected
                    Attached Files

                    Comment


                      #90
                      Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                      I thought that there was a line of two pixels thick but i see that the line is only a separation between two type of colour visualisations, this brings me to another type of defect, i have a Samsung tv with that defect, i saw that benting the screen the defect varies and it seems a faulty connection, maybe the cof soldering..

                      Comment


                        #91
                        Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                        OK, I can try the COF contacts. I will also measure VGH on the seconed COF
                        The lines are present , actually I noticed 2 groups now. very strange. they are very faint.
                        I'll check tomorrow

                        P.S I used x25 magnification. This job must be done in easy to work situation. The floor was bad idea, inexperience

                        Comment


                          #92
                          Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                          What Left side error would cause the screen not to show even the Logo ? ( right side alone shows half a logo with , Now, all White Left

                          Comment


                            #93
                            Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                            What about connecting VGH from the distribution board to the 2nd TAB input TP ?

                            Comment


                              #94
                              Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                              All White on the left means probably that the left cof are not working at all, this brings to a faulty first left cof or another missing important signal like vcc (i guess 3,3v)..
                              connecting power to the second cof is totally unuseful because them are started by a signal from the first cof..

                              Comment


                                #95
                                Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                                I found 3.3V when I measured the COF. Should I re-measure ?

                                Comment


                                  #96
                                  Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                                  i lost my message fu***!#@%^&

                                  Comment


                                    #97
                                    Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                                    i have to shrink my deleted message, the first left tab cof is defective, the only solution is to strip it off and pray..

                                    Comment


                                      #98
                                      Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                                      I'm a bulldog

                                      What I did just now is disconnect the bypass on VGH TP on the board : I do get same image as before , but few horizontal lines.
                                      Thus I assume something isn't right with my 2nd attempt.
                                      I will re-do . I wish I didn't cover the TPs since I have to expose again. BUT, I will add 2 wires to that board VGH TP : if the 3rd attempt will fail like now , I will try the Exit VGH TP , and if that fails I will try 2nd TAB Entry VGH.

                                      I uploaded a close-up of 1st Tab I took with x25 Loupe : I told you I found 3 TPs with continuity , near the VGH TP, but I don't see them connected , maybe on the board ? - I will work on THAT . even with x25 it hard to see. I hope I will manage if needed
                                      Attached Files

                                      Comment


                                        #99
                                        Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                                        don't waste time with output points, i told it to you, the cof is faulty, i noticed now because i've checked better your photos, that 18v means it is the left side entry point for vgh, this means the connection exists but a short within the cof pulls down the tension..

                                        Comment


                                          Re: Can you dignose from the photo ? . Toshiba 65S2650EV

                                          Could it be that those 3 "continuity" TPs ( near VGH but not connected to it) represent the short inside the COF ? If so, maybe I can isolate the lines ..?
                                          Also, If I compare entry and exit TP clusters , in the 1st Tab, They are not mirror image.

                                          So, before I take the 1st TAB Off : Is there any possibility to do anything else, even , any, faint and remote and small chance ?

                                          Comment

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