DECstation 5000/240 problems

[Michael Kraemer]

hello world,

I have a DECstation 5000/240 which passes all
selftests (gfx, mem, ...) until it stucks
after the console says "prcache".
The rear site LEDs hint towards a failing CPU module
("processor cache"?), but the docs say that
"prcache" refers to the optional NVRAM module.
Problem is, I don't see any such thingy
inside my machine.
I assume it should look like a RAM module,
but the machine is "only" filled with 15 32MB
modules.
(This obscene amount of RAM is one
of the reasons I'd try hard to revive this box,
just imagine, a 1992's machine with almost
half a Gig of RAM, must have been worth
a fortune back then :-)
I already did the usual VooDoo magic,
i.e. swapping/cleaning/reseating modules,
to no effect.
Could it be the box suffers from phantom pain,
i.e. it once had an NVRAM and the config info
is still kept at some secret place?

[R.A.Omond]

Post by Michael Kraemer
hello world,
I have a DECstation 5000/240 which passes all
selftests (gfx, mem, ...) until it stucks
after the console says "prcache".
The rear site LEDs hint towards a failing CPU module
("processor cache"?), but the docs say that
"prcache" refers to the optional NVRAM module.
Problem is, I don't see any such thingy
inside my machine.
I assume it should look like a RAM module,
but the machine is "only" filled with 15 32MB
modules.
(This obscene amount of RAM is one
of the reasons I'd try hard to revive this box,
just imagine, a 1992's machine with almost
half a Gig of RAM, must have been worth
a fortune back then :-)
I already did the usual VooDoo magic,
i.e. swapping/cleaning/reseating modules,
to no effect.
Could it be the box suffers from phantom pain,
i.e. it once had an NVRAM and the config info
is still kept at some secret place?

Michael, just a hunch ... "prcache" *might* refer to Prestoserve,
which was reasonably common on DECstations at the time.

Prestoserve was a cache to help NFS performance.

[U***@gmx.de]

Hi,

Post by Michael Kraemer
hello world,
I have a DECstation 5000/240 which passes all
selftests (gfx, mem, ...) until it stucks
after the console says "prcache".
The rear site LEDs hint towards a failing CPU module
("processor cache"?), but the docs say that
"prcache" refers to the optional NVRAM module.
Problem is, I don't see any such thingy
inside my machine.

[del]

It looks like a strange memory module and fits into a mem slot as well.
Mine has an extra LED on it, I believe. Should be easy to spot, if you
have one.

Good luck,
Uli (who has 2 dead power supplies for his 5k/240...)

[willh]

Post by Michael Kraemer
hello world,
I have a DECstation 5000/240 which passes all
selftests (gfx, mem, ...) until it stucks
after the console says "prcache".
The rear site LEDs hint towards a failing CPU module
("processor cache"?), but the docs say that
"prcache" refers to the optional NVRAM module.
Problem is, I don't see any such thingy
inside my machine.
I assume it should look like a RAM module,
but the machine is "only" filled with 15 32MB
modules.
(This obscene amount of RAM is one
of the reasons I'd try hard to revive this box,
just imagine, a 1992's machine with almost
half a Gig of RAM, must have been worth
a fortune back then :-)
I already did the usual VooDoo magic,
i.e. swapping/cleaning/reseating modules,
to no effect.
Could it be the box suffers from phantom pain,
i.e. it once had an NVRAM and the config info
is still kept at some secret place?

The prcache quick test of NVRAM on power-up tests the scratch
area of the optional NVRAM module. The diagnostic status bit
in the diagnostic register on the NVRAM module is set on
failure. The optional NVRAM module can be installed in
memory slot 14,

prcache/clear - Zero NVRAM Memory

The prcache/clear command quickly writes zeros to all NVRAM
memory addresses. To run the prcache/clear command, type:

t 3/prcache/clear [board]

When you type the prcache/clear command, replace the optional
board parameter with the slot number of the NVRAM module.
Because the DECstation 5000 Model 240 must have the
NVRAM module installed in slot 14, the default value is set
at 14.

http://deathrow.vistech.net/~cvisors/DEC94MDS/pm38cmg2.pdf

[Michael Kraemer]

Post by willh
The prcache quick test of NVRAM on power-up tests the scratch
area of the optional NVRAM module. The diagnostic status bit
in the diagnostic register on the NVRAM module is set on
failure. The optional NVRAM module can be installed in
memory slot 14,
prcache/clear - Zero NVRAM Memory
The prcache/clear command quickly writes zeros to all NVRAM
t 3/prcache/clear [board]
When you type the prcache/clear command, replace the optional
board parameter with the slot number of the NVRAM module.
Because the DECstation 5000 Model 240 must have the
NVRAM module installed in slot 14, the default value is set
at 14.
http://deathrow.vistech.net/~cvisors/DEC94MDS/pm38cmg2.pdf

Thanks for the reply, but I know all that and I seem
to have all documentation which can still be found on the net.
Unfortunately the machine does not have an NVRAM,
yet it seems to hang exactly at that test,
it does not return to the console prompt.

[U***@gmx.de]

In <h4q77k$l40$00$***@news.t-online.com> Michael Kraemer <***@gsi.de> writes:
[del]

Post by Michael Kraemer
Thanks for the reply, but I know all that and I seem
to have all documentation which can still be found on the net.
Unfortunately the machine does not have an NVRAM,
yet it seems to hang exactly at that test,
it does not return to the console prompt.

Have you tried booting it with only 2 or 4 memory modules?

HTH,
Uli

[Michael Kraemer]

Post by U***@gmx.de
[del]

Post by Michael Kraemer
Thanks for the reply, but I know all that and I seem
to have all documentation which can still be found on the net.
Unfortunately the machine does not have an NVRAM,
yet it seems to hang exactly at that test,
it does not return to the console prompt.

Have you tried booting it with only 2 or 4 memory modules?

yes, to no avail.
In the mean time, I suspect that I might have been misled
by that console message.
Looking more closely, the "prcache" message appears shortly,
being replaced by the cursor only. At this
point the machine stucks, with the rear side LEDs being
off-off-on-on off-off-on-off
Troubleshooting manual section says it's a problem with
ROM code failed to load, on slot 3, which means base slot.
The recommendation is to reinstall CPU and/or memory,
did that already.
Could this mean the CPU module (or the ROM on it) is dead,
and I'd need to call the DEC service for sending me a replacement? :-(

[U***@gmx.de]

In <h53oqd$4fq$02$***@news.t-online.com> Michael Kraemer <***@gsi.de> writes:

[del]

Post by Michael Kraemer
Looking more closely, the "prcache" message appears shortly,
being replaced by the cursor only. At this
point the machine stucks, with the rear side LEDs being
off-off-on-on off-off-on-off
Troubleshooting manual section says it's a problem with
ROM code failed to load, on slot 3, which means base slot.
The recommendation is to reinstall CPU and/or memory,
did that already.
Could this mean the CPU module (or the ROM on it) is dead,
and I'd need to call the DEC service for sending me a replacement? :-(

In most of the cases where I had error reports like that, I needed to clean
the contacts of the memory slots and the memory modules - yes, both. Sometimes
more than once. I never had a failing CPU (well, once, but that was because
it was overheating as I was too careless...)

HTH,
Uli