[Info-vax] Used DS-10 or equivalent recommendations?

[Scott Dorsey]

MG  <marcogbNO at SPAMxs4all.nl> wrote:
>
>I remember one of my DS10s had worked fine but from some time
>onward, after one or more power failures, it began to exhibit
>unpredictable behavior.  It would power up, run, etc., but I
>would get bizarre errors under VMS, with no explanation for
>it in the logs.  The kind of errors you may also expect from
>memory faults, but I swapped the memory (and also the disk)
>between my DS10s and the problems were really specific to
>one DS10.

This sort of thing is typically noise on the power supply rails.  Usually
either a bad capacitor in the power supply or a bad decoupling cap somewhere
on the cpu board.  An ESR tester will find them quickly.

>My conclusion was at the time that perhaps the PSU wasn't in
>order and, just like now, they're relatively hard to come by,
>not to mention quite costly.
>
>Reparing a PSU can be quite dangerous and one has to be
>careful, but that hopefully goes without saying.

It's not particularly hard to just shotgun out all the capacitors on a
power supply, and with a machine of this age with this sort of symptom
it's worth doing it because even if it doesn't fix the current issue it
will prevent future ones.  These machines were not designed to last 
forever, the way a PDP-8e was.
--scott
-- 
"C'est un Nagra. C'est suisse, et tres, tres precis."