Panasonic TH-42PX75U - Can See Menus But No Picture

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  • TransAm84
    Member
    • Feb 2012
    • 15

    #1

    Panasonic TH-42PX75U - Can See Menus But No Picture

    Hi everyone, I am fairly new to this hobby but thanks to this forum i was able to repair my computer monitor!

    I picked up a 2007 Panasonic TH-42PX75U for next to nothing, knowing it had an issue. The TV turns on ok with the remote and button on tv. All menus seem to work as well as volume & channel/input display. There is no picture or sound from any input. I have checked and re-seated all cables. Can i assume the A board is faulty?

    Any help is greatly appreciated.
  • capkid
    Badcaps Legend
    • Oct 2010
    • 1339
    • United States

    #2
    Re: Panasonic TH-42PX75U - Can See Menus But No Picture

    I'd assume that the A board is faulty. I like to hook up a portable DVD player to test. It sounds like you've checked out the inputs.
    Last edited by capkid; 07-27-2013, 09:58 AM.
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    • TransAm84
      Member
      • Feb 2012
      • 15

      #3
      Re: Panasonic TH-42PX75U - Can See Menus But No Picture

      Also there is no sound. Occasionally when cycling through the inputs I will see this green or white horizontal or vertical lines. Also, at one point, with a DVD player plugged in, I got this big white block with a thin green line above it (As seen in the pic). Thanks again
      Attached Files
      Last edited by TransAm84; 07-27-2013, 10:00 AM.

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      • TransAm84
        Member
        • Feb 2012
        • 15

        #4
        Re: Panasonic TH-42PX75U - Can See Menus But No Picture

        Assuming its a faulty A board, is there a way to repair it? Finding one online is proving to be difficult. Also, I am unsure of the function of the A Board and the D Board, can anyone explain them to me in layman terms? Thanks again

        Comment

        • capkid
          Badcaps Legend
          • Oct 2010
          • 1339
          • United States

          #5
          Re: Panasonic TH-42PX75U - Can See Menus But No Picture

          eBay: http://www.ebay.com/itm/Panasonic-TH...item1c351bb971

          Verify the part number. I'm not a fan of buying main boards on eBay, because there are quite a few faulty ones out there being sold as working. You may have to vary your search to find one online.

          If you can have the main board professionally repaired, that would be even better. I've never tried repairing a Panasonic main board myself. This company MAY be able to repair it - you'd have to check with them to see if this is one they actually repair. They repaired a Samsung main board for me: http://www.moduslinkptstvboards.com/...andreturn.aspx

          http://www.moduslinkptstvboards.com/...BS-P13519.aspx

          Here's what I've learned about the A board and D board:

          The A board, or main board, is essentially the brains of the TV. It controls functions such as video and audio processing, remote control signal processing, on/off power off signals, etc. The D board, or logic control board, is sort of a coordinator between the various boards in the TV. For example, it takes signals from the main board and converts them so they can be displayed by the various "picture" boards. It normally controls a lot of the display timing so that pixels fire appropriately.
          Last edited by capkid; 07-28-2013, 02:22 AM.
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          • kevinm34232
            Badcaps Legend
            • May 2012
            • 1884
            • USA

            #6
            Re: Panasonic TH-42PX75U - Can See Menus But No Picture

            Originally posted by capkid
            eBay: http://www.ebay.com/itm/Panasonic-TH...item1c351bb971

            Verify the part number. I'm not a fan of buying main boards on eBay, because there are quite a few faulty ones out there being sold as working. You may have to vary your search to find one online.

            If you can have the main board professionally repaired, that would be even better. I've never tried repairing a Panasonic main board myself. This company MAY be able to repair it - you'd have to check with them to see if this is one they actually repair. They repaired a Samsung main board for me: http://www.moduslinkptstvboards.com/...andreturn.aspx

            http://www.moduslinkptstvboards.com/...BS-P13519.aspx

            Here's what I've learned about the A board and D board:

            The A board, or main board, is essentially the brains of the TV. It controls functions such as video and audio processing, remote control signal processing, on/off power off signals, etc. The D board, or logic control board, is sort of a coordinator between the various boards in the TV. For example, it takes signals from the main board and converts them so they can be displayed by the various "picture" boards. It normally controls a lot of the display timing so that pixels fire appropriately.
            What was wrong with the Samsung main board that they repaired? I've got a 40" and 46" sitting here with suspected main board issues, and they are $100+ if you can find them.

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            • capkid
              Badcaps Legend
              • Oct 2010
              • 1339
              • United States

              #7
              Re: Panasonic TH-42PX75U - Can See Menus But No Picture

              Originally posted by kevinm34232
              What was wrong with the Samsung main board that they repaired? I've got a 40" and 46" sitting here with suspected main me issues, and they are $100+ if you can find them.
              The Samsung would run for a while, sometimes for hours or days, then it would emit a horrible squealing noise. IIRC, the picture also would scramble. ModusLink charged me $70 for the repair. Their prices vary, though. I ran the TV for a week without issues before I sold it.
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              • kevinm34232
                Badcaps Legend
                • May 2012
                • 1884
                • USA

                #8
                Re: Panasonic TH-42PX75U - Can See Menus But No Picture

                Did they say what they repaired on it? How long did it take? Wonder how they diagnose and test them..

                Comment

                • capkid
                  Badcaps Legend
                  • Oct 2010
                  • 1339
                  • United States

                  #9
                  Re: Panasonic TH-42PX75U - Can See Menus But No Picture

                  Originally posted by kevinm34232
                  Did they say what they repaired on it? How long did it take? Wonder how they diagnose and test them..
                  I didn't ask, and I doubt they would have given me an answer. I think the total turnaround, including shipping back to me was about a week.
                  Last edited by capkid; 07-28-2013, 12:20 PM.
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                  • azus26
                    New Member
                    • Jul 2012
                    • 1
                    • CANADA

                    #10
                    Originally posted by TransAm84
                    Hi everyone, I am fairly new to this hobby but thanks to this forum i was able to repair my computer monitor!

                    I picked up a 2007 Panasonic TH-42PX75U for next to nothing, knowing it had an issue. The TV turns on ok with the remote and button on tv. All menus seem to work as well as volume & channel/input display. There is no picture or sound from any input. I have checked and re-seated all cables. Can i assume the A board is faulty?

                    Any help is greatly appreciated.
                    i have the same problems do you find the issue ?

                    Comment

                    • diif
                      Badcaps Legend
                      • Feb 2014
                      • 6978
                      • England

                      #11
                      Re: Panasonic TH-42PX75U - Can See Menus But No Picture

                      Originally posted by azus26
                      i have the same problems do you find the issue ?
                      I would suspect the Analog Devices IC.
                      https://www.youtube.com/watch?v=qIKTbYYS6is
                      https://www.youtube.com/watch?v=QZlc6tiL1gk

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