Chosen Solution
I was told that it is a separate part, and usually costs around $35 to $50. I am referring to the part that you plug the power cord into the laptop, not the wall.
It’s called the DC-IN port. Here it is: http://www.ifixit.com/Mac-Parts/iBook-G4…. Heres how to install it: iBook G4 14" 1.42 GHz DC-In Board Replacement