[Trippynet]

Well, it's not looking good for the repaired PSU. After fitting it and booting the system up, about 5 minutes later I started getting timeout errors on the SCSI bus, and could see the main system drive powering up and down repeatedly. After considering that maybe my old system drive was dying (they're old HDDs after all), I popped in a cloned spare, and promptly ran into the same issue.

Given that my last system disk clone was actually many months ago, I popped my second PSU in, and successfully cloned the system disk (twice) without any issue - so the drive is fine (and given how many spare HDDs I have, it's nice to have plenty of backups). Got a couple more final tests to do just to be certain, but it looks as if the latest "fix" has possibly made things even worse. Final things I want to try is to see how long it'll run for before abruptly powering down (as that was the previous issue). Could be they've fixed one fault and introduced another, I'll see.

Still! It's under warranty, so I'll keep posting it back until I get a fully working PSU from them!

[weblacky]

Sorry to hear things aren't proceeding so well for you with your repair.

I've actually been accumulating Indigo2 parts/systems and test equipment for my PSU repair experiment.  While I'm not ready just yet, if you do end up with a PSU that's still problematic at the end, I may have a interesting troubleshooting method to diagnose your PSU.  We'll see if I get there!

In the mean time, you could get a standard molex y-splitter and plug it between the sled and hard drive (one end feeds the drive) and use a multimeter in MIN/MAX mode (fast MIN/MAX would be even better if you have it on your meter) on the other end to see the voltage levels the drive is getting.  That could tell you if you've got generally low voltage or if it's wiggling.  That would be valuable feedback for the people fixing your PSU.  It might indicate what "stage" is malfunctioning on the PSU (if your multimeter voltage test shows something).  

Please keep us informed on the future progress as it develops.

[Trippynet]

Actually, I think I may have been a bit hasty before. The repaired and re-capped PSU now seems to be working OK. I have an extra molex splitter in my system which feeds an additional fan I fitted some time back, and I'm now thinking that there was a ropey connection here when I popped the repaired PSU originally.

Before I sent back the PSU for further investigation, I decided to pop it back in and do more testing to see exactly when the fault occurred and how I could replicate it - ie, trying just one HDD to start with, then building up by adding a second HDD, CD drive, fan etc. to see exactly when the PSU started to wobble, also with the aim of testing voltages etc. My thought being that the more info I provided, the more the repair company might stand a chance of replicating the issue and fixing it.... and the PSU hasn't wobbled once so far! I've had it running for up to an hour and a half so far with all bits re-installed, HugeEngineModel stressing the CPU to 100% and the system running rock solid stable.

Might try a particularly long stress-test over the weekend, run a bunch of applications at the same time for several hours to really stress the thing and see if I can coax an issue out of it. However given that the PSU originally used to last no more than 30 minutes before cutting out before I sent it off the first time, it's doing quite well at the moment.

Assuming it works, I'll speak with the repair company to see if I can find out which extra bits they replaced other than the caps.

[Trippynet]

OK, this PSU is now repaired methinks. Must have just been a dodgy connection with the molex connector the first time I ran into issues. I've now had the system running for 8 hours solid whilst scripting, playing music, running screen savers etc. and its not missed a beat. I'll see if I can find out from the repair company what they changed the second time around to fix the abrupt shutdowns. Given that they'd already re-capped the PSU without the fault originally being fixed, I'd be interested to know what it was that eventually fixed it.

For anyone in the UK curious, the company I used was Advance Product Services. They seem to have used decent 105C caps as well - and from what I can see they did replace all of them, so hopefully the PSU will give me many more years of good running...

[Trippynet]

The company got back to me today regarding the fault. I've been told that there were four 56K 2 watt resistors that measured slightly low resistance, plus a 10R surface mount resistor that measured slightly high resistance. The company changed all of these and it seems to have fixed the issue.

Not sure if someone else who has an intermittent Indigo2 PSU may find this handy to measure and replace these and see if it helps fix the issue? May be worth a shot!

[reed]

hey its a bit off topic but i have a purple indigo2 with solid impact card that wont start at all...i got a refurb power supply from ian at sgi depot and that did not solve the problem...the machine had not been started in over 10 years but by the looks of it the pots all look clean , no swelling or leaking anywhere as far as i can tell...i have a lot of good work on this machine i want to retrieve and just want the glory of this beast to shine again! i am in the philadelphia area and need someone to look at this, any ideas? shipping this to england to sgi depot costs way too much...i would hate to scrap this for parts but that is on the horizon.....

[TriOx]

[*]Crimson: if you've got a Cherokee PSU ("black") you're out of luck. They seem to self destruct if (when) they die. I replaced mine with the PowerOne ("silver") model. This requires a different 5V bus bar so is not a simple part swap.
[*]Onyx/Challenge: power systems are complex and don't age well. First there's one (or 2 or 3) OLS to convert 220VAC to 48VDC. All but the last rev are a fire hazard and should have been recalled/switched out except they more often than not aren't. Then every board in the system converts 48VDC to whatever it needs using DC-DC converter modules. These are sealed and not serviceable. The systems boards are so thick I've never been able to desolder anything from them.

OMG, thanks for the trip down memory lane Jan-jaap! I remember the silver Crimson supplies being quite rare as the machines came out to surplus. My RE came originally with a silver PS and 6 fan tray. The other Crimson, I did the bus bar and 4 fan to 6 fan tray swap while kicking the dead Cherokee to the curb.

Roughly around 2002, an SGI tech came to my house to replace both my Onyx and Challenge L OLS. The replacements had a round red sticker that could be seen from the back of the machine. I didn't have a support contract or anything. I just called the local office and they sent the guy out within a couple days. Def don't want to run the old style OLS, especially if you keep your Fuel on top of the deskside, harhar.