Quicksilver G4 using an ATX Power Supply?
Submitted by Hawaii Cruiser on September 20, 2007 - 8:32am.
PowerPC Macs
It's been discussed earlier, but I'd like to narrow this topic down to a clear consensus. Can you use an ATX PSU to power a Quicksilver without having to supply the +28v (actually +25v ?) input to pins 9 and 22 as diagrammed here and here? --Except on the OutOfSpec page he clearly states that you'll need an extra wallwart power supply to provide something close to +28v for the two pins (which is also added to this kit). But you only need the full 28v in order to power an ADC, right? Otherwise, a lesser voltage will suffice which can all be provided by the ATX alone. This would also explain this ridiculously priced "adoptor"(you have to cut them some slack on the spelling, they're German, just imagine Austrian Arnold Schwarzenneger pronouncing it).
From what I'm reading in different threads here at 'Fritter, a few people are stating that you only need 12v to pins 9 and 22, so all you would have to do is tap 12v from other lines on the ATX PSU, or simply from the P4 four-pin connector on newer ATX PSUs. You could use a 20 pin to EPS12 24pin extender, or a simple 20 to 24pin ATX extender to safely make the mods. Am I following correctly so far?
Now, where I'm getting confused is that I'm also reading, as in the last posts on alk's thread that there is also the suggestion that, instead of 12v, you can even use +5v as an alternative. Does this actually work? It is stated there by stewart710 that the +5vSB is actually preferable since it is always on standby. +5vSB is already coming into pin 9 on an ATX PSU. But will that +5vSB be needed for pin 22 rather than pin 9? And then, pin 9 requires at least 12v? The "white" lead on pin 22 is the trickle, right? So the standby line would be optimal for pin 22 because the trickle alerts the motherboard to a power on? And pin 9 provides power to the ADC, so it would need at least 12v to convince the motherboard of its adequate performance, correct?
So here's the synopsis as I'm concluding it. The ATX's pin 9 +5vSB line needs to be transfered to pin 22, and then pin 9 needs to tap into a +12v line, assuming you're not going to be using an ADC, which I won't be using. And then, pin 11 needs to tap a ground. It's as simple as that.
Am I getting all this right, or am I simply totally confused? thanks