Xref: utzoo comp.sys.dec:3665 comp.os.vms:28443
Path: utzoo!attcan!uunet!clyde.concordia.ca!news-server.csri.toronto.edu!rutgers!cbmvax!grr
From: grr@cbmvax.commodore.com (George Robbins)
Newsgroups: comp.sys.dec,comp.os.vms
Subject: Re: Help?  Dead VAX 11/750 ...
Message-ID: <13497@cbmvax.commodore.com>
Date: 28 Jul 90 22:30:25 GMT
References: <3035@unocss.unomaha.edu>
Reply-To: grr@cbmvax (George Robbins)
Organization: Commodore, West Chester, PA
Lines: 31

In article <3035@unocss.unomaha.edu> dent@unocss.unomaha.edu (dent) writes:
> Hello...
> 
> The Student Chapter of ACM here at the Univ. of NE at Omaha owns a VAX
> 11/750, w/ 8 Megs RAM, Floating Point Accellerator, 2 RM05's, an RM03,
> a DMF32, and a DELUA. (also a TS11, plus other misc. parts)
> 
> We've been running VMS on this system for about 4 weeks, until "suddenly"
> we started getting errors about a corrupted memory cache.  The 750 would
> then start restarting itself randomly, dropping to the monitor '>>>'
> 
> All of these problems seemed to align chronologically with a board swap we
> had just performed: we took out a DZ11 board and replaced it with the DMF32
> mentioned above (which does DMA, so it doesn't seem likely that it would
> contribute to an interrupt problem...)  Because of the timing, however,
> we yanked the DMF32 back out, but the problem was still there.

Well, DMF32 boards are notorious power suckers, so it may have put your
power supply around the bend.  General advice is to 1-by-1 pull out the
CPU boards, flex a little, shove on chips, replace boards, blow dust out
of system, power supplies and fan assembly/filter, check voltages, kick
twice, cycle power and so on.

If this doesn't work, call around to used equipment vendors and see if anyone
wants to donate you another 750 or a CPU boardset, the value of bare CPU's has
declined awfully close to zero...

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)