28 Mar
2002
28 Mar
'02
9:46 a.m.
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).
Antonio