Chosen Solution

My power button is stuck and cannot be pressed down to start the laptop. I think its just a purely mechanical problem. But to check that I have to get the cover off. How do I do that ?

Follow this guide through step 32: iBook G3 12" Top Shield Replacement You will now have access to the switch. The switch comes with the top case. Here is a list of the available top cases: http://www.ifixit.com/Mac-Parts/iBook-G3