Introducing myself and VAXstation 3100 help needed

[Robert Jarratt]

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Bryan C.
> Everly
> Sent: 22 January 2016 13:10
> To: cctalk at classiccmp.org
> Subject: Introducing myself and VAXstation 3100 help needed
> 
> Hi Everyone,
> 
> Jay West was kind enough to point me to this list and I just wanted to
> introduce myself before I start begging for help.  :-)
> 
> I started out life coding on a CDC Cyber-170 and from there moved up
> through the TRS-80 model I before finally taking the plunge and purchasing a
> very early Apple ][+.  After that, I moved up through the Apple //e and finally
> landed in the 32-bit world with my Amiga 1000.  I had an Amiga 2000 and then
> finally sold out and lived in the WinTel world until being "rescued" by a PPC32
> Mac Mini.  From there it's been Mac mostly but I've always loved older, less
> mainstream gear.
> 
> When I rediscovered OpenBSD and the fact that it has some of these
> "distaff" architectures as full tier-1 citizens, I started playing around.
> At this point I have that same MacMini (macppc), a Sun Blade 100 (sparc64),
> an Alphastation 500/400 (alpha), an SGI O2 (mips64), an HP C3700 (hppa) and
> a VAXstation 3100 (VAX).  Everything except the VAX is running 5.9-current
> on OpenBSD and doing surprisingly well.
> 
> I'm trying to bring the VAXstation back to life (picked it up on eBay for less
> than $30 US) and I'm having a problem (here's where I start begging for
> help).
> 
> The diagnostic LEDs on the back (thanks to
> http://home.claranet.nl/users/pb0aia/vax/3100leds.html for helping me
> decode them) finally settle at:
> 
> 1000 1010
> 
> Which I'm reading as a failed self-test in the "MM" subsystem.  I'm assuming
> MM=Memory Management Unit.  I have also noticed it never spins up the
> hard drive (that's a working drive I personally installed so I know it's good) or
> tries to access the floppy.
> 
> On the advice of some of the folks on the list, I stripped the machine down to
> the bare board (man there was a lot of dust in there).  I found (as I expected
> to) that the CMOS battery had leaked but there wasn't a lot of corrosion on
> the board near the connector and the solder pads in that area looked
> particularly beefy so I don't think I have any board or trace damage from that.
> 
> When I powered the box up with everything removed, I got the same MM
> subsystem failure error so I don't think it's the memory board.  I'm still
> waiting on my final cable to be able to get on the serial console so I can't run
> TEST 50 yet but I'm hoping someone on here can point me in another
> diagnostic direction.
> 
> Or, does a failed "MM" test mean the CPU or main board are done with and I
> need to replace it?
> 
> Many thanks in advance for any help you can give me.
> 
> Thanks,
> Bryan

It does appear that you have a problem with the memory management unit. It doesn't sound very promising, but TEST 50 output would help.

Regards

Rob