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    Samsung PS42C450B1W Picture Noise/Solarization

    Hi All,

    I'm just starting to look at this 7 year old Samsung PS42C450B1W that, on first power up the picture is fine. Then, after a few minutes, the picture becomes distorted with highlight noise and solarization effects. This is present on tuned images along with USB sourced video files.

    On brief inspection there was no obvious visible bad caps, etc.
    Looking at threads related to solarization, many point to the T-Con board (named logic board in this service manual)

    Before I dive in and start measuring voltages, are there any general pointers for this kind of fault?

    I've found the service manual which was too large to upload so have provided a link here:
    https://www.dropbox.com/s/0znrcyicw8...dp_tv.pdf?dl=0







    Many thanks
    Attached Files

    #2
    Re: Samsung PS42C450B1W Picture Noise/Solarization

    Do a search of the forum for running the test pattern which will eliminate or otherwise any problem with the mainboard.
    Willing to help but I'm no expert.

    Comment


      #3
      Re: Samsung PS42C450B1W Picture Noise/Solarization

      I assume you mean the inbuilt test patterns accessed via the Service Mode.

      If so, each test pattern displays varying amounts of the distortion I describe above.

      Does this indicate the main board is suspect?

      Comment


        #4
        Re: Samsung PS42C450B1W Picture Noise/Solarization

        No. It's disconnect the cable from control board to main board and place a jumper link on the control board but |I'm not 100% certain if its's pins 1 to 2 or 3 and 4 which is why I suggested searching the forum.
        Attached Files
        Last edited by dick_barton; 10-28-2019, 08:38 AM.
        Willing to help but I'm no expert.

        Comment


          #5
          Re: Samsung PS42C450B1W Picture Noise/Solarization

          I've disconnected the main ribbon cable (blue tab) and tried every permutation on jumpering the pins but get no signal on the screen.

          I've searched the forum but can't see anything relevant

          Comment


            #6
            Re: Samsung PS42C450B1W Picture Noise/Solarization

            Originally posted by Nevillet View Post
            I've disconnected the main ribbon cable (blue tab) and tried every permutation on jumpering the pins but get no signal on the screen.

            I've searched the forum but can't see anything relevant


            https://www.badcaps.net/forum/showthread.php?t=26790
            Willing to help but I'm no expert.

            Comment


              #7
              Re: Samsung PS42C450B1W Picture Noise/Solarization

              Problems with gamma correction ?.

              Comment


                #8
                Re: Samsung PS42C450B1W Picture Noise/Solarization

                Hi Dick, thanks again for your help.

                Following the instructions in the post you cite I am in service mode born out of the T-Con board.

                It is cycling though the various test patterns and displays the solarization distortion I described above.

                What can be concluded and Is there a component level fix possible for this fault?

                Comment


                  #9
                  Re: Samsung PS42C450B1W Picture Noise/Solarization

                  What writes on the IC surrounded by red?
                  Attached Files

                  Comment


                    #10
                    Re: Samsung PS42C450B1W Picture Noise/Solarization

                    If may well be an issue with the control board needing to be replaced.

                    This looks like a possible replacement if you want to try changing it.
                    https://www.ebay.co.uk/itm/T-CON-LVD...sAAOSwxDxclgZW
                    Last edited by dick_barton; 10-30-2019, 10:36 AM.
                    Willing to help but I'm no expert.

                    Comment


                      #11
                      Re: Samsung PS42C450B1W Picture Noise/Solarization

                      Hi

                      The IC you indicated has no markings (checked with microscope)

                      Comment


                        #12
                        Re: Samsung PS42C450B1W Picture Noise/Solarization

                        I've just ordered the t-con board from eBay.

                        BTW: It still has the same fault: When it first turns on it's fine but after a couple of minutes it exhibits the solarisation effect fault.

                        Comment


                          #13
                          Re: Samsung PS42C450B1W Picture Noise/Solarization

                          I think the gamma correction is faulty.

                          Comment


                            #14
                            Re: Samsung PS42C450B1W Picture Noise/Solarization

                            Originally posted by yokoono View Post
                            I think the gamma correction is faulty.

                            Forgive my ignorance: Which board should I be looking at re gamma correction?

                            Comment


                              #15
                              Re: Samsung PS42C450B1W Picture Noise/Solarization

                              I installed the replacement T-con board but unfortunately the symptoms remain the same:

                              Good picture immediately after switch on. After a couple of minutes the picture becomes distorted on the highlights, similar to solarization.

                              Can you suggest any next steps?

                              Many thanks.

                              Comment


                                #16
                                Re: Samsung PS42C450B1W Picture Noise/Solarization

                                That's a pity. Can you check your voltages as given on page 56 of the manual. The correct voltages for your set will be as given on the voltage label on your set.
                                Willing to help but I'm no expert.

                                Comment

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