[rescue] braindead O2

[Matthew Haas]

Hi everyone,

 Just wondering if anyone has any pointers to good SGI diagnostic tips...
I have an R5000 @ 180MHz O2 (college bought it back in 1996, has the
original SGI cube logo) that I've been using... it originally had two 64MB
modules in it, but back in July we bought a 512MB kit for it (four 128MB
modules). Two of the modules appeared to be defective, causing various
combinations of soft and hard ECC errors.

 So today I noticed the August freeware is out, so I figure I'll update
the machine. But I yank out the two questionable modules first, and reseat
the remaining (believed "good") modules into slots 1 & 2.

 I turn on the machine, and not paying much attention, I walk away for a
few minutes.. I *think* I got the chimes and whatnot. But when I returned
to the machine, the PROM screen was quickly scrolling by with tons and
tons of ECC errors.

 I hit the power button twice, and the machine powers off.. I remove the
mainboard and move the modules to slots 3 & 4 (maybe slots 1 & 2 became
bad somehow)... but when I went to power on the machine again, the power
button had no effect.

 After some monkeying around (luckily I have another O2 handy that I was
able to swap mainboards to test parts. I got it to power up again. So I
replaced it with the original mainboard, and as soon as I plug in the
power cord, the power comes on and stays that orange color.. no chimes, no
signs of intelligence. I hope it didn't just get up and die.

 I've tried it with different sets of memory modules to no avail. I even
tried setting the "Flash Clear" jumper on the mainboard and that hasn't
made any difference.

 I've hooked up a serial cable and am trying to get any clues... but so
far it doesn't seem to be spitting anything over the serial port. (serial
cable w/ null modem, plugged into serial port 1 on the O2).

 Any clues or pointers would be greatly appreciated. I originally rescued
the machine from a store room and brought it back into service. I would
hate to see it return there for good.

---
 Matthew Haas
 Corning/Geneseo, NY