[callahan]

The connectors alone don't supply all the voltage. The prongs on the frontplane provide HV (IIRC 24V) rails for some systems.

Based on labels screened onto the frontplane, they supply 3.3V and 5V (with one of each pair ground).

See http://imgur.com/xw0rbk5 (the 3.3V label is partially obstructed).

The problem is I assume many of the pins don't supply power until the computer is on, and there is no easy access. The best option is probably to potentially sacrifice an Octane by soldering monitoring leads to the back of the front plane or just cutting access panels into the case and monitoring directly.

Edit: And the other reverse engineering challenge: Some of the PSU pins must supply data, presumably digital, given that the OS can determine the installed power supply model and S/N.

[soviet]

This thread is old, sorry to reanimate it but ipurchased a new PSU for my octane a wile ago (ended up getting another one later).
The PSU arrived in bad shape it was poorly packaged and the handle was broken.

When using the power supply the psu acted intermittently working for a wile and the octane could shutdown randomly at any moment.
XIO errors and other random stuff show up in the logs before power down

After checking inside the PSU several times found the issue inside, the big coils in the psu developed cracks around the solder joints, re soldered them and this fixed the PSU issues immediately.

So maybe only a good visual inspection of the PSU can get you an easy fix it worth checking.