17 Apr
2007
17 Apr
'07
3:42 a.m.
Scott Quinn wrote:
I recently acquired a SGI IRIS Indigo R4k machine that
was
nonfunctional. After a bit of troubleshooting I tracked it down to the
PM2 (processor module daughtercard, R4400 + oscillator + 1MB cache),
which has visible damage to two of the cache RAM chips (smoke holes and
cracks). I am trying to trace back the likely sequence of events that
lead to this happening so it doesn't happen again. AFAIK in the R4400SC
the cache memory is attached directly to the R4400 with the exception
of the power leads, and the R4400 has all cache control logic
integrated. The PSU voltages have been checked and are within specs,
with no excessive ripple.
In my experience, chips do not blow up without an external cause that
drastically increases the current flowing through the chip, however I
also have zero experience with SRAM chips failing in a "spectacular"
manner. Is this possible/likely? The other option seems to be the R4400
dying and taking the cache with it. Any ideas on where to proceed from
here?
The PM2 module is electriacally identical, and mechanically close enough to the modules
used in the Indigo2, so if you can score a battered I2 with R4400SC150 module, you can
stick that into the Indigo and have the fastest possible configuration of that model.
Maybe removing the cache chips will result in a functional PC module, but I never tried
that.
They are very nice machines. Built like tanks. Even a defunct one serves as a nice example
of how workstations *should* be constructed.
,xtG
tsooJ
18 Apr
18 Apr
3:44 p.m.
On Tue, 17 Apr 2007 09:42:54 +0200
Joost van de Griek <jvdg at sparcpark.net> wrote:
They are very nice machines. Built like tanks. Even a
defunct one
serves as a nice example of how workstations *should* be constructed.
Except the
PSUs. I think I am now past a dozen Indigos with blowen up
PSUs. A friend with experience in repairing SM-PSUs tried to fix the
PSUs once - and finaly gave up. Fortunately it is not hard to replace
the PSU: http://www.aopc98.dsl.pipex.com/indigo_psu_rescue.html
SGI hardware is nice, but quirky.
--
tsch??,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/
19 Apr
19 Apr
4 p.m.
Jochen Kunz wrote:
On Tue, 17 Apr 2007 09:42:54 +0200
Joost van de Griek <jvdg at sparcpark.net> wrote:
I'm glad my little web page came in useful :-)
The machine that PSU is in is a R4400, full memory, Elan graphics, fast
9GB drive. Been running fine for years.
If anyone repairs an existing PSU and manages to fill in the missing
pins (A,B & C) on my pinout I'd be happy to update the site.
James
They are very nice machines. Built like tanks.
Even a defunct one
serves as a nice example of how workstations *should* be constructed.
Except the
PSUs. I think I am now past a dozen Indigos with blowen up
PSUs. A friend with experience in repairing SM-PSUs tried to fix the
PSUs once - and finaly gave up. Fortunately it is not hard to replace
the PSU: http://www.aopc98.dsl.pipex.com/indigo_psu_rescue.html
SGI hardware is nice, but quirky.
20 Apr
20 Apr
11:48 a.m.
On Thu, 19 Apr 2007 21:00:20 +0100
James <james at machineroom.info> wrote:
I'm glad my little web page came in useful :-)
Small world. ;-)
Thanks for puting this valuable information online.
The machine that PSU is in is a R4400, full memory,
Elan graphics,
fast 9GB drive. Been running fine for years.
The machine in question was a basic
R3k with LG1 owned by a friend.
I did the soldering, but I don't know if he has tested the machine
meanwhile. (I soldered an ATX power socket to the wires so that he can
add a ATX PSU later on his own.)
If anyone repairs an existing PSU and manages to fill
in the missing
pins (A,B & C) on my pinout I'd be happy to update the site.
I can't
remember exactely. One or two where related to the reset switch
and one was GND, or somthing like that. Sorry.
--
tsch??,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/
6284
days inactive
6287
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3 comments
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participants (3)
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james＠machineroom.info -
jkunz＠unixag-kl.fh-kl.de -
jvdg＠sparcpark.net