[reed]

get a refurb psu from sgi depot....still does not power on, i have re-assembled outside of case to check for any possible shorts, no luck...simply no power whatsoever, at least before i got a weak pulse that tried to make the fan move, now nothing whatsoever..any ideas? anyone i can ship this unit to for repairs? of course i dont want to spend too much on this but i have a lot of architectural work on this machine....thanks

[reed]

I know a guy who specializes in vintage hardware and has skills in soldering. He does a lot of capacitor replacement. But this is in Vancouver, BC and he is pretty busy. But for the right price I suspect he could do the work without much trouble. I can ask him about availability and his rates. He knows SGIs reasonably well and generally is very well versed in old, odd hardware. I believe Ian does or is considering doing this kind of repair/restoration work, but I'd guess he's putting time and effort into fixing some of the more expensive SGI parts still in demand by commercial users and he's in the UK, so not ideal for North American folks.

Ideally someone would restore a variety of SGI PSUs/boards and keep some in an inventory and offer trade in exchanges for a fair price. Maybe SGI Depot will do that in the future? I'd like to send the PSUs for my Indigo2s in for inspection. I've been told that if the caps leak significantly while a machine isn't being used they can eat into the boards and that powering them up in a leaking/damaged state can make them useless, but you have a much better chance of successful repair if you never power them up after leaks have occurred.

cool thanks...it looks like my board and card are all looking like they are brand new with no swelling or leaky pots, it just simply wont turn on at all even with a new power supply.......another computer mystery among many

[TriOx]

hi reed, I recently fired up two of my I2 Impact after a 12+ year slumber and both have similar problems. In my case the LED never came on at all, but the PS and mid-plane fans ran when I hit the power switch. Following the troubleshooting section in the I2 owners guide, so far I got one of them to boot by following step 2 on pg 227 (pushing down on the mid-plane). The other I will have to take apart to check the mid-plane seating and for shorts. I might also just try pushing harder haha:

"It’s okay to press quite firmly on the top of the midplane wall."

Now the reason I bring this up, on pg 226, the first power on test, where LED is off, contains both mid-plane and CPU as possible culprit. Since my fans actually ran rather than just twitch, and you already said you re-assembled outside the case, I think we can eliminate mid-plane which leaves CPU. Did you try to re-seat the CPU? Basic instructions are on pg 268 - 269.

My memory is quite foggy so please don't get your hopes up too much, but I used to have a pair of Teal I2, even farther back, and I used to muck with R4k serial eeproms, and such, and your twitchy fans are giving me some serious deja-vu.

https://irix7.com/techpubs/007-2849-004.pdf

[TriOx]

After I last posted, I packed both the I2 Impact into a vehicle and took them home from the office. The R4k which I previously got going by pushing on the midplane, wouldn't start again. This time I pushed down on the midplane with the power supply started, as I pushed on the midplane I saw the LED go on and it booted and continued to reboot after that.

I got the second I2 Impact R10k booting finally too, this one needed both the midplane and cpu pushed down firmly to make sure they were seated. I seated the cpu with the power off though, no sense chancing that, lol. In both cases I felt movement. So it seems that long term storage and movement can cause the bits to wiggle apart.

Note, in all cases the symptom was no LED at all and the Power Supply and midplane fans were running, power button couldn't power back down, had to pull the plug to power off.

[weblacky]

Not to hijack this thread,

But I feel to keep the topic going I'd thought I'd add that, I'm still trying to get to a place where I can effectively do something about SGI power supply repair. I recently got into several SGI Indigo2 power supplies (already working) to do a clean out, washing, and inspect what it would take to have to work on them.

I'll tell you that non-IMPACT supplies seem very doable....IMPACT ready supplies on the other hand...are a total nightmare to handle. I only worked with one IMPACT PSU (can't find the model right now) that was only for Solid IMPACT only R8000/R10000 Systems. It had HUGE, SOLID, Flat ribbon-est cables inside the case from the main transformer out the top of the transformer and directly soldered into the second board (face to face like a sandwich).

These cables were big, didn't want to move, and too short to fully pull the two boards apart to clearly see anything, in the end all could do was clam-shell open the supply for cleaning. It was obvious I'd have to desolder something to even set the board flat somewhere. My gut says based on the stresses, likely desoldering the main transformer would better then desoldering the large flat ribbons coming out of it. Either way...whoever authorized that design at SGI should have been shown the door long ago.

I know this will make servicing these IMPACT PSUs very hard when compared to Octanes, Indy, O2, Etc...these IMPACT PSUs are a real hassle. Anyone who really does them will need to rig up a holding jig and likely need to do component tests via the backside of both boards with a desoldering tool to try to work parts out while the boards are still like only 2 inches apart. Not fun.

My point? Cost - I can say, for me, even if I were very familiar with this design from experience (I'm not right now), just the space, time, handling, knowledge investment isn't going to make fixing these specific power supplies cheap. I don't know what others are willing to pay for working PSUs, but I'd think we'd be into the $275USD or higher range after all that work and such. These supplies also get extremely filthy (like nothing I've ever seen) so cleaning will have to be a part of repair.

Unless several symptoms become templated, I suspect an 1.5hr - 2hr of labor will be required from receipt to ready to sell/ship back.

I'm not saying to throw it away, nor am I saying to give up hope. But these old supplies are very dense, lots of small passive components that may require checking, so the cost will be a concern. Obviously when these SGIs were NEW and advanced, these kinds of costs make perfect sense, but as a shelf-warming collectable, maybe not.

Anyone who's been in an Indigo2 IMPACT PSU and lived to tell the story feel free to add your two cents. I really hope we can find an efficient way to solve these issues that doesn't require huge costs. Right now, it's cheaper to hold on to your dead PSUs, and keep trying to buy working used ones over repair. Until someone can get a workflow going that can give reasonable pricing to fixing these.

[reed]

Not to hijack this thread,

But I feel to keep the topic going I'd thought I'd add that, I'm still trying to get to a place where I can effectively do something about SGI power supply repair. I recently got into several SGI Indigo2 power supplies (already working) to do a clean out, washing, and inspect what it would take to have to work on them.

I'll tell you that non-IMPACT supplies seem very doable....IMPACT ready supplies on the other hand...are a total nightmare to handle. I only worked with one IMPACT PSU (can't find the model right now) that was only for Solid IMPACT only R8000/R10000 Systems. It had HUGE, SOLID, Flat ribbon-est cables inside the case from the main transformer out the top of the transformer and directly soldered into the second board (face to face like a sandwich).

These cables were big, didn't want to move, and too short to fully pull the two boards apart to clearly see anything, in the end all could do was clam-shell open the supply for cleaning. It was obvious I'd have to desolder something to even set the board flat somewhere. My gut says based on the stresses, likely desoldering the main transformer would better then desoldering the large flat ribbons coming out of it. Either way...whoever authorized that design at SGI should have been shown the door long ago.

I know this will make servicing these IMPACT PSUs very hard when compared to Octanes, Indy, O2, Etc...these IMPACT PSUs are a real hassle. Anyone who really does them will need to rig up a holding jig and likely need to do component tests via the backside of both boards with a desoldering tool to try to work parts out while the boards are still like only 2 inches apart. Not fun.

My point? Cost - I can say, for me, even if I were very familiar with this design from experience (I'm not right now), just the space, time, handling, knowledge investment isn't going to make fixing these specific power supplies cheap. I don't know what others are willing to pay for working PSUs, but I'd think we'd be into the $275USD or higher range after all that work and such. These supplies also get extremely filthy (like nothing I've ever seen) so cleaning will have to be a part of repair.

Unless several symptoms become templated, I suspect an 1.5hr - 2hr of labor will be required from receipt to ready to sell/ship back.

I'm not saying to throw it away, nor am I saying to give up hope. But these old supplies are very dense, lots of small passive components that may require checking, so the cost will be a concern. Obviously when these SGIs were NEW and advanced, these kinds of costs make perfect sense, but as a shelf-warming collectable, maybe not.

Anyone who's been in an Indigo2 IMPACT PSU and lived to tell the story feel free to add your two cents. I really hope we can find an efficient way to solve these issues that doesn't require huge costs. Right now, it's cheaper to hold on to your dead PSUs, and keep trying to buy working used ones over repair. Until someone can get a workflow going that can give reasonable pricing to fixing these.

---

i finally bought a used psu from england and i still could not power up....caved and bought another on ebay and it powered up no problem...finicky psu now i have 2 broken ones....anyone want them for free? pay shipping from philadelphia

[tseter]

If we figure out the pins of the Impact PSU, maybe it is possible to "emulate" the original PSU using general purpose laboratory power supplies. That is, if the Indigo2 requires 5V on pins X,Z, and ground on W, we simply provide that voltage from the outside using an adjustable laboratory power supply. The last time I have looked at the Indigo2 Impact PSU, it had a huge number of cables and connectors, so we would probably need very precise information about the required voltages.

[reed]

1-4-2020 : i bought a used power supply and it fired right up

[jan-jaap]

If we figure out the pins of the Impact PSU, maybe it is possible to "emulate" the original PSU using general purpose laboratory power supplies. That is, if the Indigo2 requires 5V on pins X,Z, and ground on W, we simply provide that voltage from the outside using an adjustable laboratory power supply. The last time I have looked at the Indigo2 Impact PSU, it had a huge number of cables and connectors, so we would probably need very precise information about the required voltages.

The number of cables is a way of keeping the current per cable within same limits.

Replacing the original power supply with something different is certainly possible, I did exactly that with the Personal IRIS 4D/35: https://forums.irixnet.org/thread-1468-p...l#pid10036

Of course, the IRIS was technically fairly simple: only 5 and 12V, no soft power on, ample space in the chassis and PSU pinouts documented. The Indigo2 has more voltages and less space available so finding something suitable will be harder.

Re. a lab PSU: I guess technically that's possible, but beware the voltages need to come up within a certain time frame (or even order), otherwise there's no telling what the attached system may do.

[sunray]

1-4-2020 : i bought a used power supply and it fired right up

That nice, perhaps you should plan for replacement of some caps before it breaksdown, its always easier to fixe before it breaks.

If you know how to solder that is.