Hi all,
new guy here trying to contribute, hope this isn't a dead forgotten thread
. I just wanted to post after building the circuit for the V1.6 and let all know that it will
NOT work. The 5VSB on the ATX PS will not take the full 5V load of the xbox. So, I tried to put a blocking diode on it and connect it to the other ATX 5V wires(red), but no go. The diode and load of the xbox drags it down to <4V, and this is not enough to get it to fire up (no 3.3v on start pin with power button). I did get it to work...sort of by jamming on the ATX all the time. Turn on the ATX all the time (ATX pin 14 to ground). Connect all 5v outputs on ATX to 5v on Xbox. Connect all grounds on ATX to grounds on xbox. Connect ATX 12V to Xbox 12V. Connect ATX PwrOk to Xbox PwrOk. Leave xbox start unconnected. Leave ATX 5VSB disconnected. Leave ATX -5v, -12v & 3.3v disconnected. Thats it..No circuit. Bad part is ATX runs all the time, but the xbox acts normally, power button powers it on and off .. eject power up etc.
**Warning - Do not plug in the Power Supply while it is on...Use swith on ATX or unplug from 120v to turn off **
**Warning - Do not use the power switch on the ATX to turn Xbox off it could damage a transistor on the xbox always, power the xbox up and down normally with its power button. Once Xbox if powered down you can turn off ATX**
No flames please, I know this is a rather crude mod. I will be working out the circuit to get the ATX to power on and off correctly. The circuit in this post for the V1.6 only provides a momentary grounding of the ATX Pwron pin when the power button on the xbox is pressed, so it turns right back off when you let go of the button. It will need a latch.
Dang that was long winded..Hope it helps someone.
Any updates...me also stuck with not able to get the 3.3V PWRON signal as i split the 5V stby from ATX to the 4 xbox 5V stby