Power Mac G4 not booting correctly?

The clock PRAM battery could have bearing on older PowerMac not

working correctly, or exhibiting startup issues. Also burned copies of

Mac system installer CD/DVD discs have been known to fail.

Reset PRAM/NVRAM can help. [Instructions tell you "for Intel-mac" - not

newest hardware - Apple Silicon; but still works for vintage pre-intel HW.]

Deeper resets varied with vintage Mac hardware; such as original PMU,

& old power resets; unused in modern hardware & macOS. Listed below:

Types and Functions of various Apple/Mac power-management chips:

• SMC: Systems Management Controller.
• SMU: Systems Management Unit.
• PMU: Power Management Unit.
• CUDA: Capacitive Unit Discharge ASIC (Application-Specific Integrated Circuit).

• G4 power mac PCI, CUDA / PMU buttons - Apple Community

https://discussions.apple.com/thread/3163770

• PowerMac G4 (AGP Graphics) | Digital Tech (archive/user manual)

https://www.scribd.com/doc/55669677/Power-Mac-G4-AGP-Graphics

Later of these were oldest forms of reset/controllers.

https://duckduckgo.com/?q=cuda+pmu+power+resets+powermac&t=ffab&ia=web

Most of these no longer have instructions to reset vintage hardware.

Such as unplugging the logic board from power supply, and press power

button; to clear the onboard memory, etc. ~ To troubleshoot antique

Macs, it's good to find original info; later processes & ideas don't work.

[Rarely, blank disk media & optical drive may produce workable duplicate.

Very conditional at best; seldom good results, w/ many 'coasters' created.]

Reading through ~ may be other hardware issues behind these failures.

• X Lab - X-FAQs - thexlab.com

Should you replace the battery, then reset the logic board? That may force

drain power quickly from a new battery. (Instructions have been obsoleted

from the Support site; links to those from elsewhere, fail to show content.)

..Good luck & happy computing.!

🌿⛵️🎣🌻🌤🌎🌙🌞🐝😳🐶

Yes the CMOS battery could definitely be it. I've seen it prevent booting off an iMac G4 when it is too old.

Make sure your 10.4.6 tiger disc is the retail release:

Any disc that says Dropin/OEM, or system specific will not work with the PowerMac G4.

I would not even bother with the 10.0 or 10.1.3 disc, as neither had permission repair support, which are helpful if you still usign Mac OS 9.

The PCI graphics model had another anomaly, no Firewire booting, so you have to make sure the jumpers are correct for master and slave internally to allow booting. That's something you will need to determine if the Zip drive is occupying, or if the hard drive is limiting. The jumpers on the drive themselves, little plastic tabs with holes need to be aligned properly for master/slave cable select, and different on each drive. I seem to also recall that the ATA cable colors indicate which drive should be master and slave, but don't have the documentation.