Just realized that the "In order to turn the power supply 'On' the logic board ties the 'Power ON' pin to..." bullet in my previous post may be incomplete.

I wrote that the Beige ties the 'Power On' pin to Ground, but it is possible that in the Beige G3 that depends on the setting of that jumper on the logic board. That may be exactly what that jumper controls -- whether 5VSB or GND is used to trigger 'Power On'.

It is true that a 7500 PS expects 5VSB on 'Power On' as an 'ON' signal and an ATX PS expects GND as an 'ON' signal, but it may be that the Beige G3 logic board can supply either 'ON' signal depending on how the jumper is set.

I'm not sure, but I think that is the case.