Sanyo DP42746 bad buffer??

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  • Mr Bill
    Badcaps Veteran
    • Nov 2011
    • 648
    • USA
    #1

    Sanyo DP42746 bad buffer??

    I'm wondering if the upper buffer is on its way out. The top and bottom buffers are the dreaded samsung LJ92-01202A & LJ92-01203A that are known for failure. I did re-seat the connectors going to the upper buffer board but it made no change. I also checked the buffer to see if it was shorted and that tested good too. Voltages (Va, Ve, ect) are almost spot on as per the sticker on the panel, within +/- .02 volt. Just wanted to get a few opinions since i'm not very expierienced with plasmas. Sorry for the blurry pic but the tv is facing the wall. I can hook a source up to it if needed but i figured the picture i have you would get the general idea of my issue.

    Thanks
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    • electronicsurplus
      Badcaps Veteran
      • Jun 2012
      • 210
      • USA
      #2
      Re: Sanyo DP42746 bad buffer??

      Using a Multimeter on diode check put one lead on one of he caps - side and run the other lead along the connector (Both sides) where the buffer connects to the panel and check for any shorts. should read 600-700. the beginning will read 500 or so. if any are low then the ic leading to that trace is bad.

      Also, try removing the connector to the XSUS and see what happens

      Let me know

      Jon
      This Forum absolutely the best and, the most helpful forum I have ever found anywhere. thanks to all the fantastic members here
      Help keep these from the landfills

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        • Mr Bill
          Badcaps Veteran
          • Nov 2011
          • 648
          • USA
          #3
          Re: Sanyo DP42746 bad buffer??

          i'm getting .730-.740 on both upper and lower buffers doing the test you suggested. I unplugged the x-main and i don't get a screen at all.

            Comment

            • electronicsurplus
              Badcaps Veteran
              • Jun 2012
              • 210
              • USA
              #4
              Re: Sanyo DP42746 bad buffer??

              Originally posted by Mr Bill
              i'm getting .730-.740 on both upper and lower buffers doing the test you suggested. I unplugged the x-main and i don't get a screen at all.
              Ok, now, try removing the ribbon cables, one at a time from the xsus and, let me know what happens
              This Forum absolutely the best and, the most helpful forum I have ever found anywhere. thanks to all the fantastic members here
              Help keep these from the landfills

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                • Mr Bill
                  Badcaps Veteran
                  • Nov 2011
                  • 648
                  • USA
                  #5
                  Re: Sanyo DP42746 bad buffer??

                  i disconnected the 3 ribbons on the x-main 1 at a time. I would reconnect the one i disconnected and then move to the next one. The picture doesn't look any different than the pic on post #1. When i finished i hooked all 3 back up and the screen didn't look any different than my pic in post #1. It's making me wonder if the x-main is failing. Is the IPM on the x-main the same as the Y?

                    Comment

                    • electronicsurplus
                      Badcaps Veteran
                      • Jun 2012
                      • 210
                      • USA
                      #6
                      Re: Sanyo DP42746 bad buffer??

                      Originally posted by Mr Bill
                      i disconnected the 3 ribbons on the x-main 1 at a time. I would reconnect the one i disconnected and then move to the next one. The picture doesn't look any different than the pic on post #1. When i finished i hooked all 3 back up and the screen didn't look any different than my pic in post #1. It's making me wonder if the x-main is failing. Is the IPM on the x-main the same as the Y?

                      Yes, it sure is

                      But, I would check the diodes 1st. they are under the heat-sink closest to the ribbon cable. they commonly go bad. which actually sounds like your problem more than the IPM
                      This Forum absolutely the best and, the most helpful forum I have ever found anywhere. thanks to all the fantastic members here
                      Help keep these from the landfills

                        Comment

                        • Mr Bill
                          Badcaps Veteran
                          • Nov 2011
                          • 648
                          • USA
                          #7
                          Re: Sanyo DP42746 bad buffer??

                          Originally posted by electronicsurplus
                          Yes, it sure is

                          But, I would check the diodes 1st. they are under the heat-sink closest to the ribbon cable. they commonly go bad. which actually sounds like your problem more than the IPM
                          Are you talking about the X or Y sustain?

                            Comment

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