SGI: Hardware

Went to fire up my indigo2 r10k impact today, and nothing, dead. Suspect the PSU as this seems to be a common problem on this forum.

Have removed the PSU, but would like to do some diagnostic tests first. Does anyone know the cable pins outs or know a link to them? If it does turn out to be the supply, first stop will probably be to replace the electrolytics!

Cheers, Adam

I swear the IMPACT power supplies are the flakiest crap!

I'm mid way through getting my PSU refurbished by a company here in the UK after I ended up with the same situation as you on my R10K IMPACT. They charged approx £250 to refurbish it but to my disappointment it still didn't work. Hoping to get it back to them very soon for another look.

chicaneuk wrote: I swear the IMPACT power supplies are the flakiest crap!

Yep, must agree

So far I've stripped it down and inspected. Input fuses are fine, no burst or leaking caps, and no obvious sign of damage. I reassembled and put it back in on the off chance that the strip down might have reseated any connectors, but still no joy.

At the moment I need to find out how to turn the PSU on, the equivalent of grounding the green wire on a PC PSU, but can't find any info.

Regards, Adam

chicaneuk wrote: I swear the IMPACT power supplies are the flakiest crap!

You realize the Indigo2 was sold circa 1993 - 1997?

They are now 18 - 22years old.

I do appreciate that - just that of all the discussion on SGI stuff on here, Indigo2 IMPACT power supplies seem to be particularly fragile! When I was searching for info when mine died, I turned up a multitude of threads about them.

chicaneuk wrote: Indigo2 IMPACT power supplies seem to be particularly fragile!

Some SGI power supplies are quite fragile, even turning them on and off too often can kill them. Also with older computers every time you turn them on there's a chance that something will fail. The guys video below unwittingly demonstrates the fragility of Onyx2 power supplies.

Rhodamine wrote: Went to fire up my indigo2 r10k impact today, and nothing, dead. Suspect the PSU

just two questions

• which gfx do you have? Maximum/Impact, or Solid/Impact?
• since the last time, have you kept the powercord plugged after you have switched-off the machine?

chicaneuk wrote: I swear the IMPACT power supplies are the flakiest crap!

I don't like unplugging the power cord as soon as the shutdown is completed, but with that PSU it's a must .

Solid/impact. Currently the PSU is off, actually in pieces. Normally I keep it turned off at the power socket when not in use. But it has spent the last week with the power socket on, maybe that explains the problem.

PSU is zytec 060-0027-002 rev A, 229435507 rev D. Suitable for dual heading, so had assumed it would be so over specified that it would be robust. Guess I was wrong

I have taken on the challenge of repairing, currently trying to reverse engineer a schematic for the 'high voltage' board. Seems to be a more recent model than the one on Ian's website, as now has connector on the high current outputs from the transformer.

Best of luck with it! Anything that helps aid our understanding of these and how to fix them in future has to be a good thing!

Trippynet wrote: Best of luck with it! Anything that helps aid our understanding of these and how to fix them in future has to be a good thing!

Thanks, will post schematics if/when I manage to generate them. Will be a case of doing it when I can. Got the first 10 components down, another 290 to go!

This is the newer version of the hv board for those that are excited by such things.

Regards, Adam

I'd like to know the reason why the IP28's PSU is warm (not hot but warm) when you forget to unplug the power cord while the machine is off: it means there is flowing current somewhere, that is also the reason why you'd better unplug the power cord once the machine is switched off.

In the PC world, every ATX psu has a circuit that always provides 5V@100mA to the motherboard, the real reason of this was just to feed a circuit that continuously monitors the LAN, listening for "wakeup on lan" packets, and in case of such an event, the circuit does switch electricity to the second stage of psu, so the machine turns on.

All the ATX power supply units do not really switch off like AT, and a 100 mA current flows through them, while all the AT units are really switched off, and no current flows through them.

ivelegacy wrote: I'd like to know the reason why the IP28's PSU is warm (not hot but warm) when you forget to unplug the power cord while the machine is off: it means there is flowing current somewhere, that is also the reason why you'd better unplug the power cord once the machine is switched off.

Opinions on that last bit vary. If you do that the machine will warm up / cool down every time you use it and the thermal stress isn't good for the longevity either. But to be honest all my machines are disconnected as well when I don't use them. First of all, most of them are 20 ... 30 years old and I'm afraid something is going to set the fire to the house one day. I have a family with small kids and that's unacceptable. Also, each of them will use a couple of watts when plugged in (but powered down), and with two dozen systems this adds up. A powered down Onyx2 consumes ~ 25W if I remember correctly -- more than my fileserver (Supermicro Xeon / 32GB /10TB) when it's idling. I'm not an ecomentalist (I drive a VW with a 2.0 TDI engine ) but that's just silly.

ivelegacy wrote: In the PC world, [...] ATX power supply units do not really switch off like AT, and a 100 mA current flows through them, while all the AT units are really switched off, and no current flows through them.

Same for almost all SGIs, with the exception of the Professional IRIS, the Personal IRIS and the Indigo. They may not support wake-on-lan, but they do "soft" start. This not only avoids big clunky power switches but also limits the inrush current when the system is powered on.

Also, bear in mind that the Indigo2 was designed in 1992 and released in 1993. Soft-power-off PSUs were decidedly in their infancy at this point - ATX didn't come along for PCs until 1995, so all PCs of the time still had clunky manual power switches.

Add onto that, the Indigo2 was designed for performance and reliability, not really for power efficiency, and this is probably why it pulls around 12w when off, and why the PSU feels noticeably warm. And why mine always gets switched off at the wall when not in use!

To be honest, a far worse system from a PSU point of view is the Fuel. This was released in 2002 - so should have a much more mature PSU in it from a soft-off point of view, however it still pulls 9w when off. That's a bit crap.

motivation: we are too lazy, sometimes (too often) we forget to unplug the plug
solution: FP hack
propose: I do not have an indigo2/Ip28 on hand, but I think we could apply the same wicked plan

edit:
moved to the specific topic

99% chance it's the supply and it just needs a recapping. The parts are cheap and easy to get, and the job itself isn't very hard. I personally wouldn't spend a lot of time reverse-engineering it.

http://www.sgidepot.co.uk/i2psu.html

Black Cardinal wrote: 99% chance it's the supply and it just needs a recapping

Good theory, confirmed by the practice experience: I agree with the following!

Every electronic component eventually dies, but the expected lifetime for electrolytic capacitors is quite a bit shorter than most parts you'll find in the average computer. Unfortunatley, these capacitors play a vital role in the functioning of the powersupply of your computer.

mean time between replacements, MTBF, everything can be expressed by a Weibull Distribution , very useful tools come when probability theory and statistics are applied to electronics, topics like … using WD "to evolutes" reliability systems, charming math!

Electrolytic capacitors rely on the surface area created between an etched metal electrode and a liquid electrolyte (which forms the other electrode) to function. Unfortunatley, this liquid electrolyte has a nasty habit of evaporating over time, which can range anywhere from 25+ years for a very large/cool capacitor to 5 or fewer years for a small/hot cap.

sadly the Truth with old technology, especially about electrolytic capacitors: I got very bad experiences with IBM S/36, I mean I found a lot of dead electrolytic capacitors, so the 99% of the fault was related just to them.




fingers crossed
good luck =)

Hopefully it is just the caps, I will certainly be replacing them. But, I think a better understanding of these old supplies will not go amiss.

Modern electrolytics have improved significantly since the IBM issue days due to better sealing. Unfortunately that doesn't help these legacy systems.

Cheers, Adam

Trippynet wrote: Also, bear in mind that the Indigo2 was designed in 1992 and released in 1993. Soft-power-off PSUs were decidedly in their infancy at this point - ATX didn't come along for PCs until 1995, so all PCs of the time still had clunky manual power switches.

But Sun had soft-power on/off at least as early as 1992 (SS10), and Apple had it since 1988. It wouldn't shock me to hear that some computer had it in the early '80s.

robespierre wrote: But Sun had soft-power on/off at least as early as 1992 (SS10), and Apple had it since 1988. It wouldn't shock me to hear that some computer had it in the early '80s.

The PowerOne power supplies used in 4D PowerSeries had active soft start. PowerOne built them from the mid-eighties until circa 2008. Later series had PFC as well.

But with configurations ranging from 1000 - 4000VA, soft start quickly becomes a rather essential feature ...

Interesting reading, i support the idea to at least barely get the power up and shutdown sequence and signals that control those procedures. My long term plan is to completely remove the old psu and put something brand new inside, although modern ATX psu's are more larger and would'n fit inside original Indigo2 casing. I investigated a bit and found new switching dc-dc step down converters from Intersil that can give needed current and voltage (solely or in bridge mode):

http://www.intersil.com/en/products/pow ... dules.html

The problem with new ATX psu's is that they are putting more or less all the current in the 12V lanes, so comparing it eg. to Indigo2 impact psu that is 385W total power, one should use at least 850W modern ATX psu to get same amperage distributed (with step-down), which is not ideal from energy efficiency perspective. There are ATX 2.0 psu's that put more power in lower voltage lanes but even those require modifying output to fit Indigo2 voltages.

This is the sticker from my impact psu that died time ago, it's the newer version 060-8002-001 but not meant for dual head. Intersting enough, aside the really non standard 3.5V they needed also those darned -5V for god knows why