O2 Power Supply Basics

For my O2s I have 060-0022-001 and 060-0032-001 PSUs. I *think* I read that one shipped in R10k vs. R5k but I can't find my notes on it. Anyone have docs that prove or disprove that?
 
Is one a Rev. N? Thought the Rev. N models were for O2+ and higher end O2...I could be wrong, remembering what someone else told me.
 
Thanks for that @weblacky. The 0022 models are both Rev A1. I have a couple of 0032 that are Rev N, the rest of the 0032 are Rev J.
 
Ah, OK it's unrelated then. I didn't really know that there were multiple models of O2 power supply as I really haven't paid attention to them in over a decade. That's something that I will need to know too, so if anyone has knowledge of any real differences that would be of use.
 
@Elf With your advanced knowledge of these PSUs, could you hazard a guess to the cause of o2's not turning on with the regular front-button anymore?

ie; https://forums.sgi.sh/index.php?threads/o2-power-on-problem.1255/

Seems both me and Jenna have connected a 'jump-start' switch connected to 'PWR ON' near the NVRAM, in order to get our systems started.

All I can say is: It doesn't *seem* to be PSU related as 1. I have tried 3 different PSUs and 2. Jenna re-capped hers and 3. I re-capped all the smaller caps in one of mine.

It also doesn't seem to be related to the frontplane, where the actual power button is, since I swapped with another frontplane.

The behavior seems to be: 1. After a 'Jump start' the system will turn on and operate fine 2. After shutting down, the machine will start again normally with the front button 3. But if you leave the system for a day, or disconnect the mains power and plug back in, it will require another 'Jump start'.

Just wondering if you have any ideas. Thanks.
 
If you feel like updating the main post, you could add these following capacitor details I got from my PSU:

Code:
Control board
0.47uf 50v x4
1uf 50v x2
220uf 16v
100uf 10v
22uf 16v
4.7uf 25v

Main PCB
220uf 450v (25mm width 45mm height)(10mm lead spacing)(pc pin)
22uf 50v
100uf 35v
220uf 16v x3
22uf 50v x3
180uf 25v
2200uf 6.3v x2 (10mm width 25mm height)(5mm lead spacing)
2200uf 25v x2 (12mm width 35mm height)(5mm lead spacing)
10,000uf 6.3v x4 (16mm width 35mm height)(7.68mm lead spacing)

From this particular model:

Screenshot From 2024-10-13 14-34-29.png
 
Seems both me and Jenna have connected a 'jump-start' switch connected to 'PWR ON' near the NVRAM, in order to get our systems started.
If it turns on with the jumper set then I think it wouldn't be a power supply issue. The power supplies are fairly dumb and just wait for an indication to turn on from the motherboard. I think this is a common issue with O2s but I'm not sure of the cause; you might also check whether the RTC is working? You could also check the standby voltage on the power supply, I guess, if you really wanted to rule anything out there.
 

About us

  • Silicon Graphics User Group (SGUG) is a community for users, developers, and admirers of Silicon Graphics (SGI) products. We aim to be a friendly hobbyist community for discussing all aspects of SGIs, including use, software development, the IRIX Operating System, and troubleshooting, as well as facilitating hardware exchange.

User Menu