42PF7320A\37 Strange problems...

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  • badwr2002
    New Member
    • Feb 2012
    • 3
    #1

    42PF7320A\37 Strange problems...

    I was recently given a Philips 42 inch plasma model number 42PF7320A\37, after the previous owner replaced the power supply, and it still had the same problem. The TV would come on, as soon as its plugged in, which I dont think is normal. It would then stay on for about 20 minutes, then it would turn off, and turn back on, stay on for a few more minutes, then shut off, and back on, this time doing it over and over as soon as it comes on until unplugged. It also has a little distortion on the screen just before a reset. Well I decided to check the error buffer per the manual, and it was full of 00's. So I decided to leave the TV alone, and let it go off and on until I got a red light flashing, or an error code. After about 3 hours of hearing this thing click and still nothing im lost. It sounds like a bad solder joint, or a component overheating, but the only chip that is pretty hot at the time of shut off is just below the 2 ribbon cables on the Small Signal Board. I have tried unplugging each board from the power supply, same problem with each. It comes on, works perfect for a few minutes, then goes into a reboot cycle. Any ideas? I can post pictures/video of the TV doing what it does if needed...

    Edit: I should probably add, there are no swollen caps, no burnt spots on the boards, no funny smells.
    Last edited by badwr2002; 02-08-2012, 04:10 AM.
    Tags: None
    • PlainBill
      Badcaps Legend
      • Feb 2009
      • 7034
      • USA
      #2
      Re: 42PF7320A\37 Strange problems...

      You are correct - turning on as soon as it is plugged in is unusual, but there is one possible test for that. Once it has been on for a few minutes turn if off and unplug it. Wait a minute or two, then plug it in again. If it doesn't turn on until the power button is pressed, it was 'remembering' the last state before it was unplugged and returning to it.

      The description sounds like a thermal problem. If it wasn't for the video distortion I would suggest just replacing the Small Signal Board - one is available on eBay for $40 shipped. As a test, try forced cooling (or freeze spray) on the chip on the SSB that gets hot. Also check all the voltages on the SSB.

      There is the possibility that the problem is the buffers. I have two of these, they are great sets, but if the buffers / Y-main goes they aren't worth repairing.

      PlainBill
      For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

      Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

        Comment

        • badwr2002
          New Member
          • Feb 2012
          • 3
          #3
          Re: 42PF7320A\37 Strange problems...

          Ah, seems you are correct on the powering on issue. If I turn it off, unplug it for a few minutes and plug it back in, it does actually give me a green light, and click, but then it goes back off after a few seconds and stays off. As for the "distortion" it is actually more like static. I can hear a scratching from the speakers, and see small areas of static near the top of the screen usually, and a few green/red pixels here and there.

            Comment

            • badwr2002
              New Member
              • Feb 2012
              • 3
              #4
              Re: 42PF7320A\37 Strange problems...

              Ordered a $30 small signal board from ebay, and it worked perfectly.

                Comment

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