G4 question

I have a digital audio im trying to get working again. I think the CPU is dead but to make sure will the system power up with out a CPU? As in just enough for the power supply to kick on?

I believe not. But I could be wrong.

The G4 will not power on without a CPU. The best thing to do is to test the power supply by itself. Take a small piece of wire and jumper it from the green wire (power on) and a black wire (ground). That will make the power supply kick start without being plugged into the motherboard. But you have to have the power supply plugged into the wall outlet of course.

I know that much of to test a power supply. Guess my CPU is dead or the motherboard is dead. If I can locate a different motherboard I can find out for sure.

Wait a sec, a digital audio CPU can work on a sawtooth logicboard but I would have to cut off the pins to the second IDE channel right?

Depends on the cpu. I have a 466 DA cpu set to 550 for a Sawtooth and i didn't have to take off the second IDE. Any single DA cpu's will work in a Sawtooth, they just need to be jumpered for the right speed setting.
(ex 466 DA CPU would be 350 in a Sawtooth)

Here is a chart comparing the Sawtooth cpu's and the Digital Audio cpu's for jumper settings. The red highlighted part is where they differ in jumper speeds.
Jumper settings

I tried the CPU with the sawtooth logicboard and it won't connect right unless the IDE controller is out of the way.

Great tip though for the CPU speed settings.

Ok, so by the sounds of it, you have one of the following...
Either a 667, a 733 or a dual 533 cpu from a Digital Audio. In that case, yes, you need to remove the second IDE connector and use an IDE card.

I got the 733MHz CPU module. I went ahead and bit the bullet and chopped off the pins to the 2nd IDE channel and it doesn't work. No power will go to the system. I have checked the power supply 3 times and it works fine with my tester, even work on the sawtooth with the 400MHz CPU. So I guess I have a dead CPU.

Would a sawtooth CPU work on a DA or not. I know the DA uses a 133MHz FSB and the Sawtooth uses a 100MHz FSB.

It might, but be careful not to fry the cpu. You might have to down clock it a bit. A 450 might run at 600MHz without modifications but i would check it all first to be on the safe side.

*Do this at your own risk*

Ok, this was a test i wanted to do on my own also. I have an original Digital Audio 466 and an original Sawtooth 450.
The DA 466 is set to 533 and runs fine in a quicksilver.
The ST 450 is set to 550 and Kernal Paniced once the desktop was shown.
The ST 450 is set to 500 (667 in QS) and runs fine in a quicksilver but is a bit sluggish for video playback.

Here are some shots i took while the cpu's were in my system.
*fyi. it says AGP Graphics but indeed the hard drive was a swap from my Sawtooth into my Quicksilver*
Original 733 overclocked to 800
733 System Profiler
450 clocked to 500
450 System Profiler
466 clocked to 533
466 System Profiler

I hope this helps with your cpu Knowledge

Thanks for the info RedDrag0n. I will try this out tonight.