The collected works of twix

Ah, but you haven't really maxed it out yet. It's possible to upgrade to a pentium 200 overdrive processor with MMX. I know because I once tried to upgrade the same Aptiva to the max configuration possible. Found the 200 overdrive CPU, one stick of cache (but not the second). Memory was also at 64 Mb, tried to find 32 Mb memory sticks, but also failed to find some at a reasonable price. Naturally, I used it to run OS/2.

The case was incredibly heavy, and the sliding door that covered the floppy disk and the CD-rom a cool feature. Spent a lot of time cleaning the case to make sure that the door slided downwards at the correct speed.

@Geoman,

No I don't own the Aptiva anymore. It fell down some stairs during transport and was damaged beyond repair. I salvaged the CPU, memory, cache, and other parts, but the frame itself was warped. So to the scrapyard it went. Too bad, since I got the computer for free when I purchased two Compaq Ipaq computers from somebody in the city where I live. The guy worked for Cisco, and he had a pretty impressive network installation at home. Enough hardware for a small business. Anyway, he sold me the two Ipaq's (60 Euros total) and then threw in the Aptiva and a Pentium 75 computer in for free. I wanted to use the Aptiva for a mod, but soon gave up that idea since the case was so different.

I still have the COAST cache chip. (256 Kb, asynchronous). If you can put it to use in your Aptiva, I'll be happy to send it to you. Don't know whether it will fit your particular board thigh, IBM made an alarming number of different versions.

The riser board ... Leave it out or unpowered and the Aptiva doesn't boot. What does that remind you of?

Today, I bought an Indigo, because it was only 15 Euros and looked good on the photo's supplied. Seller sold it as "defect" and had intended to gut it and use the case for a mod project (fit in an ATX board).

I've just taken a look, and it is a entry level R3000A version. The good news is that it starts up, displays a nice image on a LCD monitor, and is maxed out memory-wise (all positions occupied). It also has a (giant) hard-disk installed. The graphics is just entry level, but with a standard VGA output, so that's fine. The case looks pretty good, some minor scuff marks only. It needs to be cleaned.

The bad news: the TOD battery is empty (of course), so Indigo does not get very far into the booting process. The hard-disk is in position 2 and is marked "spare", so it might be empty. And there's no keyboard or mouse.

I guess the first thing is to install a new battery, and check if the machine boots up and shows a login-prompt?

New battery installed and the TOD error has gone. I now get an SCSI error (timeout) and a CPU board error (no keyboard and/or mouse present). I removed the SCSI drive and now get a SCSI cable diagnostic error. Powering up the SCSI drive out of the Indigo results in a burning green light, but no evidence of the disk spinning up (noise, vibration). Doesn't look too good. Maybe it needs to get a spin-up command explicitly?

Funny thing is, the machine doesn't play the introduction chime anymore after I replaced the battery.

Confused .....

Some progress,

I've managed to google a manual for the drive, a Conner CP 3540 540 Mb drive, which was probably quite impressive in 1991. As I expected, the drive was jumpered to prevent spin-up. This is most likely because the drive is marked as spare. Maybe it has never been used. The downside of this is that it may be totally empty. A less likely scenario is that it has a fresh install of Irix x.x.

The drive now powers on and spins up outside the Indigo. The bad news is that it does not start when fitted inside the Indigo case. I tested all three drive positions. When powering up, the green drive light lights up briefly, then goes out. I guess the next step is to power the drive with an external source to see whether the Indigo (PSU) can supply enough juice to start up the harddisk.

Using an external power source solves the problem with the drive, no error message on screen anymore. So it does seem to be a problem with the powering-up of the diskdrive by the Indigo. Maybe time to take the machine apart and check everything. Is it possible to remove the power supply?

I pushed out the PSU and investigated it. Looks very clean inside, no dust accumulation at all. Pushed it back in it's place. Problem not solved....

Cool! What's next? SSD drives?

Well, a sad ending to the day. I wanted to write down the exact error messages on the screen when the Indigo is doing its initial diagnostics. While I was writing down the info on the screen it "blew up". A bang and my house went dark. A quick investigation revealed the fuse had been tripped. No damage to any of the computer equipment, but the Indigo is gone for the moment.

I pulled out the PSU and it smells very burned. It was still warm as well. So what happened? What would cause the PSU to blow up? Trying to supply too much current to a faulty part? Maybe the hard-drive? The chime at start up stopped working yesterday, maybe that was a sign of things to come.

Could the mainboard and graphics board have survived?

Well, the PSU went out with a moderate bang, so I was not surprised that the fuse was tripped.

Can't see any damage to any of the parts, but I'll perform an autopsy to the PSU tonight.

Jan-Jaap, you don't happen to have some spare Indigo parts lying around?

Well, I took the machine apart, as shown here:

http://www.catwhisperer.co.uk/indigo/index.html

Very easy to do. Did not find any apparent damage of the backplane, the mainboard, and the graphics board. Nothing black, no funny smells. The harddrive still powers up happily. Final item to check was the PSU. I managed to pry the PSU open and took a good look inside. No blown caps, no blackened PCBs, no signs of molten leads or anything. But then again, I don't know what to look for. The PSU smelled bad afterwards, and now that I think of it, the machine (PSU) also gave off a faint odor just before failing as if something was overheating.

Do not scroll too far down ...... The first part was useful.

Yes, it's time for PSU design 101. I'll take out the fuses (2) today and check them - they look ok. The other clue that I have is the speaker failure (no chime at start-up). Something must have blown up though, there was a big bang from within the case when the PSU failed.

I'll keep an eye open for these items! You never know. AFAIK the second cache module does not improve things by much .....

Yes, time to get back to the topic. Didn't have too much time to continue, but ......

- Found out that both fuses are blown. There's nothing between the fuses and the mains except the on-off switch, so that is not surprising.
- The speaker still works - I suspected it because of the lack of a chime sound when starting the computer - but it seems to be OK (4 ohm resistance as stated on the speaker itself
- Absolutely no trace of any failed part (caps, etc), no broken bits, no molten leads. Everything looks very clean.

Looks like I'll have to disassemble the PSU to get to all the parts and test them (as far as is possible). I hope that I will time for that soon (Christmas holidays?).

But I'm still thinking about the "clues" and how they could me find the cause of the failure. Three things stand out:
- no sound from the speaker after power-on. The speaker is wired to the backplane connector, so maybe something wrong with the backplane?
- the harddisk was unable to spin up (the light only comes on briefly after initial power-up). Not enough power available?
- Since the system came up and was going through diagnostics, the mainboard and graphics board were being supplied with enough voltage/current/power. So the PSU did work.

Any theories are welcome.

Lying loose inside the cage were also 2 plastic parts with holes that look as if they can be screwed to a hard-disk or CD-ROM. Some kind of sled. The number is 050-8031-001 (Rev B). I can't find them on any SGI parts list.

No, it's not a drive sled, since the Indigo came with a (spare) drive installed. Here's a picture:



I assume that one of these is attached to each side of a drive, since the holes line up. My guess is that it belongs to some other machine, not an Indigo, but it is definitely a SGI part.

Anyway, I tested the bridge rectifiers this weekend. Had to do some disassembly, but I managed in the end. The bridge rectifier on the primary side seems to be gone, as I am not measuring any voltage drop over the diodes, i.e. no reading at all.

Yes, I see it now. The stand-offs are missing from the graphics card, so these "rails" cannot be easily refitted.

Still no further with the PSU, since I'm not much of an electronics man. I don't think that I can fix that.

Decided to install the spare Conner 500 Mb drive that came with the Indigo in a PC running Ubuntu. The disk tool doesn't recognize the partitions on the disk and shows wrong information. I first tried to install the partitions as XFS, did not work. Then decided that the Indigo is from 1991, that maybe the IRIX version is 4 and the file system is EFS. Mounting the partitions as EFS works fine. It appears that the disk has been partioned, IRIX (4) installed and some settings applied (network, etc). There is a root account and a guest account. I am assuming that this is a full basic installation, but without any applications.

The disk itself also works well in the PC hanging on an Adaptec 2940. It uses about 20 watts max when starting up, then about 8-9 watts in operation. So its not the drive that took out the PSU.

I don't really have a suggestion what can be wrong - but I would be interested in anything you find out. My Indigo R3000's speaker stopped working (no chime at boot-up) after i replaced the TOD battery. A little later the PSU shorted out, check the thread under "getting started" for details.
Having to bend the board suggests that there is something wrong with the attachment to the backplane?

It should post without the battery, and complain about the wrong TOD, then stop. Just an idea: check the memory slots for shorts. I once damaged a slot on the O2 by removing the memory - the contacts in the slots were damaged in the process (they stuck to the memory stick(?)). Had to install a small piece of cardboard in the slot to remove the contact.