Iris Indigo issues: PROM password and maybe RAM issues or EEPROM corruption?

flexion

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Sep 23, 2020
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I could need some help getting this Iris Indigo R3k running.

I already fixed the "tod clock" issue by soldering a new battery onto the board and with the SGI2USB adapter I was able to get past the "keyboard not found" error.

But now it turns out there is a PROM password set in the nvram which prevents me from entering the "Command Monitor" as well as the software installation menu to start installation of the OS.

- I don't have a bootable disk with a preinstalled OS, so starting up and resetting that password "the software way" does not work.

- According to "the internet" you can reset the password by removing the EEPROM, power up, enter the command monitor and insert the EEPROM again while the machine is running (yikes!) to overwrite/reset it.

but besides that it is close to impossible to insert that EEPROM through that tiny opening while the machine is running, the machine won't even start with the EEPROM removed.(LED remains green).

Additionally, the indigo seems to have another issue. most time when I power up the machine, the LED stays green instead of turning amber. a few weeks ago I was at least able to start it up with amber led (as well as SCSI disk spinning up) in let's say 50% of power up attempts.
but recently it really needs a lot of attempts to get the amber LED with startup chime, display output and disks spinning up.

I did some experiments with removing and reordering RAM modules:

- when I remove all RAM modules, LED blinks amber. every time. (won't start)
- when I just install two of four modules (one left, one right) it blinks amber as well. every time. won't start.
- when I install all four again, there is a 90% chance that I can start up successfully with amber LED (chime, scsi spinning up, gfx ok), but most times only once.. second time it's green LED again with no sign of life.. until I remove the CPU board again, fiddle with the RAM modules and insert it again. not sure why, but it's reproducable.

tried above procedure a dozen times with and without the EEPROM. with EEPROM removed I NEVER get an amber LED, just stuck at green LED.

any ideas how to reanimate this indigo?

thx!
 

Elf

Storybook
Feb 4, 2019
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While unfortunately I have no advice for the more complex issues, it might be worth trying to read off the EEPROM to see if the password is stored in plaintext? It may not be, but if you have anything at hand to dump the contents it is worth a look.
 

flexion

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Sep 23, 2020
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While unfortunately I have no advice for the more complex issues, it might be worth trying to read off the EEPROM to see if the password is stored in plaintext? It may not be, but if you have anything at hand to dump the contents it is worth a look.
thanks Elf! unfortunately I lost my EEPROM reader/writer/eraser equipment last time I moved. I think a buddy from the pinball scene still has one.. will try to see if he can have a look at it.
 
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flexion

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I think it would be worth a try to attach an SD card with OS preinstalled for the R3k with same hardware, as booting to a disk would be still possible without password as long as the boot parameters are the same. Anyone willing to share such an image?
 

mamorim01

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Oct 11, 2020
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Have you got information/pinout on the NVRAM chip that contains the password? I have seen the procedure you describe posted at SGIDepot, so there has to be some merit to it. Instead of plugging the IC live as described, which is a bit scary in and by itself specially given space constraints, I would simply pull the chip's Vcc pin out of the socket and leave it disconnected with a couple of wires and an open switch until you are ready to set the password. At that time you wish to enable the NVRAM chip, you simply close the switch effectively enabling the Vcc pin and the IC.

Quite frankly, I think I would wait to have all the spares you are about to receive so as to proceed with an IRIX installation, and clear the PROM password from there (nvram passwd_key "" or whatever). Even if the alternate procedure seems to be described at a reputable site, it looks a bit wonky and failure prone. Besides the missing spare parts, is there any other issue preventing you from carrying out an IRIX install?
 
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flexion

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Besides the missing spare parts, is there any other issue preventing you from carrying out an IRIX install?
The password protection is preventing me from installing a new OS. Without that password I can't enter the maintenance menu to boot from a different media :( the only thing available without password is boot to the missing OS.

regarding eeprom.. I also researched in that direction and even located the pin that would temporarily disable it. but meanwhile I also tried what actually happens when I power up with the eeprom removed --> unfortunately it simply does not start at all.. no GFX output, no amber led, no chime. So I think that eeprom trick will not help either.

so the only way left would probably be to insert a disk which is bootable using the same boot params set in the inaccessible prom settings.
maybe also a disk with just a small bootable maintenance shell would do the trick, as long as its bootable using the same parameters/partitions etc as used by the OS installation of the previous owner. (I can't modify any environment vars).
 

mamorim01

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The password protection is preventing me from installing a new OS. Without that password I can't enter the maintenance menu to boot from a different media :( the only thing available without password is boot to the missing OS.

regarding eeprom.. I also researched in that direction and even located the pin that would temporarily disable it. but meanwhile I also tried what actually happens when I power up with the eeprom removed --> unfortunately it simply does not start at all.. no GFX output, no amber led, no chime. So I think that eeprom trick will not help either.

so the only way left would probably be to insert a disk which is bootable using the same boot params set in the inaccessible prom settings.
maybe also a disk with just a small bootable maintenance shell would do the trick, as long as its bootable using the same parameters/partitions etc as used by the OS installation of the previous owner. (I can't modify any environment vars).
I see what you mean :confused:
 
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flexion

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looks like there is some hope for the old indigo. A generous forum member provided me a disk image for this model and I will try to boot into that one.
 
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flexion

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Yeah! "System is coming up.." using the SD image provided.
opened terminal
$ nvram passwd_key ""
reboot
password is gone!

unfortunately the board is having issues and after a few minutes everything freezes.
but well, better than nothing.

thanks again to everyone!
 
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mamorim01

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Good stuff. One step at a time...

I do not own an Indigo so I may very well be mistaken, but the troubleshooting guide indicates that you should be getting a green amber light at power up upon successful completion of the diagnostic test. An amber light seems to be indicative of a CPU or graphics board problem. This is per your original post above.


Besides the issue you describe which might point at a faulty memory module, I would check for proper contact between the CPU module and CPU board, that kind of stuff. I would not rule out the possibility of a power supply going bad either... :unsure:
 
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flexion

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Thanks! that was the manual I was looking for to get some more insights about what is going on at startup.

The manual says:

When you turn on the power switch, your system should go through these steps:
- The LED on the front of the machine turns amber and the system initiates Power-On Diagnostics.
- The system runs Power-On Diagnostics for about twenty seconds.
- When the system passes all Power-On tests, the LED turns green.
- The system boots IRIX.
(The guide is for R4k models. maybe R3k machines have a slightly different sequence regarding timing)

What my machine currently does (in those rare moments when I can actually really boot up):
- I power on
- LED immediately turns on and stays green for about 5 to 10 seconds.
- With some luck the LED now turns amber, as it should according to the manual, plays the chime, and after two or three seconds turns green. (but not 20 sec as in the guide).
- I get output on the screen and the system boots (LED green as it should be)

But most times (always after one successful startup) when I power on, the LED just stays green, forever, nothing happens (no gfx, disk not spinning up). Even pushing reset has no effect at all. From that point on, I can turn off, even unplug the power cord, turn on again, it will always just display the green LED and just does nothing..

But when I now remove the CPU board, remove each of the memory modules from the sockets and put them in again, shove everything back into the case and then power on, there is a 80% chance that I can successfully start and boot, or at least by pressing the reset button once if the LED stays green again. pretty strange. I have no idea if it's really related to memory or why removing memory for a short time actually helps, but this procedure lets me start up ONCE. if I just unplug power, remove the CPU board, wait a minute or two and then put it back in without removing the memory, I still cant start.

I will try to have a look at other components again, but there is not much which is removable.. the R3k machine has the CPU directly on the mainboard, not as pictured in the guide where CPU sits on a removable module.
 
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mamorim01

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It is really strange indeed. It sounds as if there was indeed some sort of problem with one of the memory modules, or bad contact between a memory module and a socket. If I am not mistaken those are proprietary modules, so it will be hard to find spares to troubleshoot, I would imagine.

I ran into a similar (sort of) situation a while ago with an Atari STe. It ended up being a cold solder (ie, a solder crack) elsewhere, whereas everything pointed out to be some sort of problem related with the SIMM modules. When testing/inserting the SIMM modules, pushing and shoving resulted in the motherboard bending slightly and the solder to temporarily fix itself as the crack closed. The 'fix' was fairly inconsistent as you can imagine, but it goes to say that sometimes you may be convinced that the fault lies someplace whereas it is only marginally related to the real problem at hand.

I have never seen a CPU board for this model and I do not have a good picture of the connector type, but it would not come as a surprise if there could be some sort of contact problem between the CPU board and the Indigo backplane.
 

flexion

Member
Sep 23, 2020
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Switzerland
yes it's hard to find those proprietary memory modules as well as a replacement PSU, and then it's still not guaranteed to work.
already invested several hundred dollars into additional parts to get this indigo up and running, but I think it's time to close this case and keep 'her' just for the looks :) at least 'the phoenix' booted once into IRIX to get rid of the PROM password :) it's part of the hobby
 

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