Hi all.

I got myself a dual G4 450mhz processor, installed it into my sawtooth and all was well, stopped working and could not boot my powermac G4 up anymore.

I found the only way to boot up the G4 was to keep resetting the CUDA. Now my question is does anybody know why this is so and is there anything I can do a part from pressing the CUDA.

Do you think I need a new logic board battery?

Thanks in advance.

CUDA is officially called the CUDA Microcontroller Chip, which handles powering on and off functions, system resets, parameter RAM, ADB, USB, FireWire and serial ports, and the clock.

As for what CUDA actually stands for? I honestly have no idea

This term is interchangeable with PMU switch and resetting it is also known as "resetting the logic board/motherboard".

This switch resets the Power Management Unit on the motherboard. According to Apple, the PMU does several things, including telling the computer to sleep, wake, idle, maintaining the system clock, maintaining various PRAM values, etc. (Source: http://docs.info.apple.com/article.html?artnum=95037).
How old is the battery in the computer now ? Every three to four years seems to be whats needed on my Macs. Not a bad idea as this can make your computer more stable .
Have you tested the Ram ?
Stewie

Sounds like you definitely need a new battery. That switch is not a CUDA switch, but a PMU reset button. Pressing it without knowing what you can do can crash the PMU, rendering your G4 unable to use sleep mode or possibly unable to boot.

Those batteries though can be bought at any electronics store for about $11-15. Sometimes they have wires attached which can be easily removed.

In your model sawtooth, the PRAM battery just slips right out. It's a 1/2 AA 3.6 volt lithium battery. The "average" lifetime of a PRAM battery is five years, less if the computer has not been plugged in much of the time.

http://docs.info.apple.com/article.html?artnum=95037 <-Have a read.

Dave

and don't buy the battery from an apple store where they are $24. Dick Smith sell them for $14.

Ok, i got a new battery (dick smith $15) reset all the PRAM, NVRAM etc... still have the same problem. So I did a bit of experimenting and took the battery out. Reset everything and it booted up. Time and settings all where all ok. I rebooted th mac and the same problem again. So I decided to leave the battery out and pull the plug from the power point, waited 10-20secs plugged power back in, booted mac and it booted like normal. Time & settings where all ok. (there is no logic board battery installed)

So what i have to do is unplug the mac when i finish using it. To powerup the mac i need to plug it into the power point and then press the power button. It boots up no problems. This is not a huge problem for me as it is spare machine, but it is a very confusing as to what is the problem.

It works so i guess that is all i needed it to do.

Thanks and if anybody has a clue as to what is happening that would be a bonus.