I'm currently testing an SGI Indigo2 PSU 'PEC4074'. I didn't want to just put it into a machine and hope it works so I've been bench testing it. This is a 'ground to stop' PSU which should just turn on when AC is supplied and there is some loading on the rails.
- It doesn't turn on when turning AC on
- Tried using my load resistors & also a HDD on the molex
- measured pin 5 (5v standby) which should always supply 5v even when off, it was only 0.15v.
- when turning the AC off, the 5vSB voltage slowly discharges to 0 while making an audible spiralling deceleration high pitch noise.
Valuable info on this PSU, non impact model:
https://forums.sgi.sh/index.php?threads ... asics.111/
Here are some photos: