Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!sdd.hp.com!ucsd!chiton!cdl
From: cdl@chiton.ucsd.edu (Carl Lowenstein)
Newsgroups: comp.sys.dec
Subject: Re: More MVII Hardware Help
Message-ID: <518@chiton.ucsd.edu>
Date: 10 Oct 90 15:48:17 GMT
References: <8810@pitt.UUCP>
Reply-To: cdl@chiton (Carl Lowenstein)
Organization: MPL of SIO at UCSD
Lines: 23

In article <8810@pitt.UUCP> jcd@pitt.UUCP (Jim Durham) writes:
> Second...if
>the MVII is dusty, check the voltage on the bus. The connectors from
>the power supply to the bus are cheesy and you can get over a volt
>of drop in the +5 supply. TTL doesn't work well on 4 volts.
> If you have an extender card, pull
>some module, put it on the extender, and measure with a digital
>voltmeter from ground to +5 on some chip.

1) There are test points behind the front panel cover (on a BA23)
that let you measure the +5 and +12 where it goes into the backplane.

2) The cable from the power supply to the backplane has been identified
by DEC as a known fire hazard, a mandatory ECO.  Field service will
replace it for you at no charge.  (at least they did for me)  The
new design of cable & connector seems much more reliable.  Last week
I had to shut down my MVII after 140 days of uptime, just because the
building was being re-wired.

-- 
        carl lowenstein         marine physical lab     u.c. san diego
        {decvax|ucbvax} !ucsd!mpl!cdl                 cdl@mpl.ucsd.edu
                                                  clowenstein@ucsd.edu