Clean Install on iMac G4

Pressing and holding an Option key while starting the Mac should result in showing the icons of bootable devices. Is that not happening? Press and hold it while starting or restarting the Mac. Keep holding it until you see an image, then describe what you're seeing.

Pressing and holding a C key should cause the Mac to boot from its optical drive, but it has been my experience that does not always work. Try using the Option key technique as jeffreythefrog described. I can confirm it works with G4 Macs.

Be advised configuring a firmware password precludes booting from anything but the startup drive designated in System Preferences: What is a firmware password on Mac? - Apple Support

reppie wrote:

Describing my issue earlier, I omitted an important piece of info. When trying to boot from the Mac OS 10 installer disk, the disk icon fails to appear on the screen so I can't access the installer screen. Instead, the log in window appears. What can I do to get the installer disk icon to appear?

Refer to my earlier reply below:

John Galt wrote:

Pressing and holding an Option key while starting the Mac should result in showing the icons of bootable devices. Is that not happening? Press and hold it while starting or restarting the Mac. Keep holding it until you see an image, then describe what you're seeing.

Pressing and holding a C key should cause the Mac to boot from its optical drive, but it has been my experience that does not always work. Try using the Option key technique as jeffreythefrog described. I can confirm it works with G4 Macs.

Be advised configuring a firmware password precludes booting from anything but the startup drive designated in System Preferences: What is a firmware password on Mac? - Apple Support

Your answers to the above will determine if the optical drive is working or not.

I'm unfamiliar with a Mac that old, so please forgive me if this is wrong. but you say you are using the "c" key while booting. what happens if you use the "option" key while booting?

Here are the all the startup keys:

https://www.idownloadblog.com/2016/05/23/mac-startup-key-combinations/

'C' should boot from the DVD.

Note that this key is no longer listed on the Apple startup key support document.

If you have valid disc’s, then it could be that the CD drive is either dirty or bad.

Again valid disc’s include the original disc set that came with that iMac or a later upgrade disc.

A 2003 G4 iMac originally came with a 10.2 Disc Set and can run up to around 10.5.8.

If you do not have the original 10.2 Disc Set, then you will need to use a later 10.3, 10.4 or 10.5 Upgrade DVD.

well, I'm way out of my comfort zone with a machine this old. but if you are seeing a login window, I would guess that there is a functioning OS X on the Mac. have you tried logging in with the former login name and password?

the oldest Mac I have is on OS X Lion. I was able to use the "command-R" keyboard combo while booting to get to Mac OS X Utilities. so I think you need to boot into that, then use Disk Utility to erase the mac's drive. after erasing, shut the Mac down. then you should be able to use your installer disc to reinstall OS X.

Hoping that it's not a problem with the CD drive.

If it's any consolation, the optical drive is one of an iMac's most inexpensive and easily replaced components. About $40 assuming you do it yourself.

thank you for the correction. :) like I said, "I'm unfamiliar with a Mac that old, so please forgive me if this is wrong." so I appreciate the feedback. :)