Reset button on iBook (Dual USB) computer. Note: The red dot shows the button's location. The button is not actually red.
For iBook (16 VRAM) and later models of iBook, there is no physical reset button.
That machine would have been perfect except for the DVD drive being toast but if you have a 6 pin to 6 pin firewire cable we may still be in business.
If you do start the G3 in Target mode by starting it and holding the 'T' key down. Connect the two computers together so that the G3 mounts as an external hard drive, The on the G4 open Disk Utility located in Applications/Utilities and do the following.
This is a screen shot of mine your window will look the same but be populated differently. Click on the Firewire drive that is hard against the left side of the list column then click on Repair Permissions.
Let me know.