DEC field veterans: what's KA64A's self test #21?

From: Carlini, Antonio <>
Date: Thu Mar 28 17:46:23 2002

> Gunther Schadow wrote:
>do you know what the KA64A's self test #21 is? I have two of these
>boards that just won't come up, they both stop at
>#123456789 0123456789 01

        After an extensive trawl of the manuals,
        I think I've found something.

        This is, as you have said, failing test 21.

        This is Backup Tag Store Parity Error Test.
        Not a happy CPU, I would guess.
        I have no idea how repairable this is.

        To verify (for sure) you should have
        the yellow LED off (self-test failed)
        and the red LEDs below that
        reading OFF, ON, OFF, OFF, OFF, OFF, ON
        (which is 21 in BCD - no, I don't know why!)

>system self test and get me to a console prompt, I get the error
>that these two boards didn't get to console mode. What could be
>wrong here?

        They almost certainly need the tender
        care of a soldering iron and a new chip
        or two. I have no schematics for these
        (I doubt that anyone other than the
        DEC repair centres ever did have these).

Received on Thu Mar 28 2002 - 17:46:23 GMT

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