[rescue] Unhappy MicroVAX II

[Ian King]

> -----Original Message-----
> From: rescue-bounces at sunhelp.org [mailto:rescue-bounces at sunhelp.org]
> On Behalf Of Andrew Hoerter
> Sent: Tuesday, April 16, 2013 9:07 AM
> To: The Rescue List
> Subject: Re: [rescue] Unhappy MicroVAX II
>
> On 4/16/13, Ian Finder <ian.finder at gmail.com> wrote:
>
> > Today I got it back, and it no longer wants to do anything- there
> > appears to be some gibberish on the serial lines, but that's not
definitive.
>
> Serial line gibberish can be suggestive of a data rate mismatch.  I'm not
sure
> what the VAX serial console defaults to, but 2400 or 9600 could be good
bets.
>
> Failing that, and not having any particular knowledge of the uVAX hardware,
> I'd start by checking power -- are you seeing good voltages on all the
power
> supply rails?  If power is flaky, you can see pretty weird behavior.
>

Ian, this is Ian.  :-)  Did you only check voltages, or did you scope the
lines?  The failure you're describing - won't wake up after a long nap -
immediately makes me think: power supply electrolytics.  You might read a
perfectly reasonable voltage with a voltmeter but discover that you have 20%
ripple.

If you don't have a scope, let's talk - are you still in my part of the world?
-- Ian

UNIX is the answer, but you must phrase the question very very carefully.
Ian S. King, Sr. Vintage Systems Engineer
Living Computer Museum
A presentation of Vulcan, Inc.
http://www.livingcomputermuseum.org