Apple iMac G3 (Original) - Manual (Page 21)

Problems Starting Up 21
Test and repair the hard disk directory.
Follow the instructions in Chapter 4, “Testing and Repairing Your Hard Disk Directory.”
If this doesn’t solve your problem, return to “Problems” on page 7.
Reinstall system software.
Follow the instructions in Chapter 5, “Reinstalling Your Computer’s Software.”
If this doesn’t solve your problem, return to “Problems” on page 7.