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Thread: How much RAM could possibly be bad in an old AST Six Pack Plus?

  1. #1
    Join Date
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    Default How much RAM could possibly be bad in an old AST Six Pack Plus?

    So how many 4264's could be bad on an old AST Six Pack Plus that won't
    POST? I mean, once in a while a chip or two might fail, right?

    See photo.

    Bad power supply? Lightning strike from 1985?

    -Pete
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  2. #2
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    What machine were you testing in?
    Asking because 200ns might not be quick enough for a turbo XT or 286 etc

  3. #3

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    They could all be bad

    The board could be bad

    If there are bad chips in bank 0 it might prevent the board from being recognized.

    Are the switches correctly configured?

    What Spider said.
    PM me if you're looking for 3" or 5" floppy disks. EMail For everything else, Take Another Step

  4. #4
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    It's a stock 5150.

    After the first few came up bad, I got tired of waiting for the PC to finish post and give the error code, so I just took every chip off and tested them one by one in my C64. After replacing the ones that failed (2 tests to be sure) the board comes up fine, all 640k, and passes the diagnostics.

    No telling how long the board sat in someone's garage. The RAM seemed to fail open since none of them got warm... Often when I see this RAM go bad in the past, they get hot (failed short). I remember being able to look at a board of chips on the Amiga and see the bad ones, because they would be discolored from the heat.

  5. #5
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    I had the same problem on my 5160 last week after 7 years in storage. 11 bad chips. I guess they're getting old.

  6. #6
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    The MT RAM seems to have a fatal flaw from birth. They all go bad eventually, even sitting idle.

  7. #7

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    Quote Originally Posted by rittwage View Post
    So how many 4264's could be bad on an old AST Six Pack Plus that won't
    POST? I mean, once in a while a chip or two might fail, right?

    See photo.

    Bad power supply? Lightning strike from 1985?

    -Pete
    A while back I bought an AST SixPakPlus off eBay for $10 and it didn't work. After testing every ram chip on the board, I found 3 bad ones. The board worked as expected after replacing them.
    Once upon a time, the internet sucked because it came through the phone. Now the phone sucks because it comes through the internet.

  8. #8

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    Quote Originally Posted by rittwage View Post
    The MT RAM seems to have a fatal flaw from birth. They all go bad eventually, even sitting idle.
    Is this MT DRAM in general, or certain types? Talking about the "old" ones only of course

  9. #9
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    I found (4) bad MT chips on my SixPakPlus at initial power-on and another (2) dropped dead in the first day. After replacement, things seem stable. Those early Micron RAM chips are horrid.

  10. #10

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    I've got some proprietary XT boards where nearly half of the MT RAM chips have gone bad.
    PM me if you're looking for 3" or 5" floppy disks. EMail For everything else, Take Another Step

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