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Thread: analog video board

  1. #1
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    Question analog video board

    What does the analog video board do exactly?... in the 333MHz iMac OS 8.6 96 RAM apple computer

  2. #2
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    Not sure exactly....

    My understanding is that the trayload imacs have a Power/Analog Video board - PAV. Both the powersupply and the analog video board are mounted on it. I would *guess* the AV part converts the video signal from digiatal to analog so that it can be passed to the monitor - CRTs are analog.

    Are you trying to fix the dreaded black screen on an imac, or some other problem?
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  3. #3
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    Good question and good answer.
    Thanks,
    Dave

  4. #4
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    a good explanation here
    http://www.macopz.com/columns/imacrepair/
    yes, from apple discussions...hehe

  5. #5
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    Default image shrinked and went to black

    Quote Originally Posted by unclemac
    Are you trying to fix the dreaded black screen on an imac, or some other problem?
    ...the image shrank and the screen went to black.

  6. #6
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    Macaholic's link it exactly what you need. I have heard some folks say that sometimes the problem is not the FTB, and you have to replace the entire PAV, but no idea if they are correct or not.

    The only thing I can add is that when you take your imac apart, you can test video out from the video cable, just to verfify the problem is not a dead CRT, before proceeding to replace the FTB.

    One last thing.... check this thread for the most technical detail that I am aware of here at the Gurus regarding this issue. Keep in mind there is a similar problem with the newer slot loaders, but they are completey different internally, so don't mix and match between the two....

    Good luck and let us know how it goes, and what you decide to do.
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  7. #7
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    Question Ftb

    Quote Originally Posted by unclemac
    I have heard some folks say that sometimes the problem is not the FTB, and you have to replace the entire PAV, but no idea if they are correct or not.

    The only thing I can add is that when you take your imac apart, you can test video out from the video cable, just to verfify the problem is not a dead CRT, before proceeding to replace the FTB.
    Thank you !

    FTB ?... What do each of the letters FTB represent mnemonically?...

  8. #8
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    Early imacs first released in 1998 have a tendency to suffer from video failure after a few years of use. Most commonly this is the result of the analog and video boards going bad. More specifically it is the analog board, and even more specifically it is the flyback transformer (FBT) on the analog board that goes bad. The FBT is responsible for stepping up the voltage required to make the cathode ray tube (CRT) monitor work and contains very fine, tightly wound wires inside to accomplish this.
    This is the first line from Macaholic's wonderful link. You need to read and digest this info to understand what you are up against, and if you want dive in.

    Here is an image of the FBT (the black object on the left) after having been desoldered from the AV board:



    I can help with the imac disassemble and reassemble procedures, but can't give any good advice with the actual soldering; have not done any of this kind of delicate work (yet!)
    Last edited by unclemac; 06-16-2004 at 09:35 AM. Reason: my other left....
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  9. #9
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    Question Flyback transformer

    Quote Originally Posted by unclemac
    Here is an image of the FBT (the black object on the right) after having been desoldered from the AV board:

    There is a black object to the left in the image and a small one to the right. Could it be the left object that is the flyback transformer?...

  10. #10
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    Redface

    Ahhh, yeah...my other left!

    Sorry.

    Yes, it is the big cylindrical item. If you go through the all the pages of the linked sight, it should be pretty clear what is involved.
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  11. #11
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    Question Related links

    Quote Originally Posted by unclemac
    If you go through the all the pages of the linked sight, it should be pretty clear what is involved.
    Thank you !

    What are the links to the pages of which site exactly?...

  12. #12
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    Arrow

    Thought it was pretty clear...

    http://www.macopz.com/columns/imacrepair/
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

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