Da da da.
I changed the disk drive, loaded the original operating system, booted it up and it worked.
I decided to upgrade the operating system and in the process, the upgrade failed because the DVD quit reading the OS 10.4 DVD. After that I couldn’t boot the iBook. I tried everything, which I won’t go into here. I even booted the iBook in target mode, booted using the iBook’s drive on my very old iMac and it worked.
Looks like the iBook is dead. It’s old enough that it would not be worth it to take to Apple dudes for them to fix.
Da da da. Oh, well.