vaxstation ii machine check & diags efficacy

[Joe Zatarski]

> It's a VAXstation II/GPX. I'm trying to install VMS 5.5 (from CD if it
matters; there is a CMD CQD-200 or -220 as the only storage controller) and
routinely getting machine check exceptions.
>
> Standalone backup always boots. Sometimes I get an exception the moment I
hit <enter> on a restore; sometimes in the middle of the restore, sometimes
it runs to successful completion.
>
> VMS never boots. Sometimes I get as far as the date prompt (I took out
the battery), sometimes it gets a little farther, frequently it's before
anything appears on the console at all.
>
> The exceptions booting VMS occur the same if I attach another disk with
VMS 5.5 already installed; if I replace the KA630 and M7609 with a KA655
and M7622, it all seems to run fine.
>
> The KA630 power-on diagnostics all pass, but... it smells like a memory
fault to me. What are the odds there could be a memory fault that isn't
caught by the diags?
>
> ok
> bear.
>
> --
> until further notice

Well, if the KA630 diagnostics are anything like the KA650 diagnostics, the
power on self test is not too thorough as I learned. I found 10 bad DRAMs
on a KA650, the POST only found 2 of them. The rest I had to test by
running tests from the monitor with tighter parameters.

You should get into the console monitor on the KA630 and see if you can get
a list of tests to be run with the TEST command. Sometimes they have
parameters, and you can specify more thorough tests to be run. Keep in
mind, they may take considerably longer to run than the POST does.

I'm speaking from KA650 experience here, but I was able to run the MEM_Data
test on all of memory with an address increment of 1. It took about 4 or 5
hours to complete I think, for 8MB of RAM.