iBook G4

If you have an appropriate Apple software install-restore disc (DVD) for the system

presently running on the computer, either original grey as-shipped version OS X or

a retail label later version, you can start the computer from the software on the disc

and try to see if the disk utility version on the install disc can be used to help repair

or check the system that is present on the hard disk drive.

•Try safe mode if your Mac doesn't finish starting up - Apple Support

•OS X Maintenance and Troubleshooting:

http://www.macattorney.com/ts.html

•Troubleshooting FAQs from the X Lab:

http://www.thexlab.com/faqs/faqs.html

• About the screens you see when your Mac starts up - Apple Support

• Resolve startup issues and perform disk maintenance with Disk Utility and fsck - Apple Support

With the system disc #1 in the optical drive, you could restart the computer and

hold down the C key for the computer to try & start from the system install section

of that official media disc; that can be used to run disk utility among other tools,

to repair or re-install a system; or erase the entire drive and waste all files on it.

Sometimes, a failing hard drive can corrupt system data and then it won't start.

Or if the hard drive is too full of user-added content, the system cannot run, &

so then it would need to be archived off the internal hard drive to an external

to free-up useful capacity for the OS X to run correctly again. Once files are

copied to an external archive and tested to be OK, there, the original user files

(such as image library, music, documents, video, etc) could be removed by use

of the Trash and empty. Be sure you have backups of all the important data you

have created and do not throw away System owned content, or it won't start up.

Without an install-restore DVD suitable for the kind and type, build model series

or retail version install DVD that supports the computer, you won't be able to do

much about the situation. An older computer has almost no support or repair

service except a few Apple trained independent specialists whose business is

not limited to only recent versions of hardware, but to a wider range of vintage.

If you have no experience troubleshooting or repairing a computer, I could go

on and on, or just review my old bookmarks for just this occasion to test them

for viability (if they still work) so you can read the information online.

So there are places to read and things to try, since troubleshooting involves a

degree of trial and error effort to determine if the cause of the problem is either

software or hardware; or if the symptoms result from combinations of both.

What OS X and CPU specs, is your iBook G4 working with? is it an 800MHz

or later? What OS X install discs do you have that you know came with it?

At nearly 1AM here, I'm going offline.

Good luck & happy computing! 🙂