Ok, on pin 11 and 12, what does "Power On" and "Power ok" mean? Does a signal to turn the xbox on/off go to those or what exactly do they do?

Xbox PSU Pinouts

1 +12V Yellow
2 +5V Red
3 +5V Red
4 +5V Red
5 +3.3V Orange
6 +3.3V STBY Brown
7,8,9,10 GND Black
11 Power on White
12 Power OK Blue

No idea...but they both give 3.3v when it's on...don't use it as a source of power...maybe grounding it powers the Xbox on?

well, does anyone know for sure what these two pins do?

power ok is a signal from the psu to the xbox saying that the psu is allright and everything is working as it should. (active when on, so 3.3V = ok, 0V = baaad)

power on is a signal from the xbox to the psu telling the psu to turn on all the non stb power (5v and 12V). It is pulled low by the psu and is pulled high (3.3V) by the xbox when the xbox turns on.

/pablot