Depends on what is wrong with it. If it is loose, you may be able to fix it by carefully attaching it. If it is okay mechanically but does not produce a space when typing, it probably needs to be very carefully removed and cleaned underneath.
Settings
128mb is pretty low, but if your ibook runs on mac OS 9, then it is not that bad.
Press space bar
Mac OS X 10.4 (Tiger) can be installed on an iBook Dual USB (G3 processor) by inserting the installation disc and double clicking the Install icon.
An iBook G3 Clamshell needs to be running Mac OS X 10.3.4 (or later) for iLife '05 to operate. Depending on the particular version of Clamshell there may be problems with the amount of hard disc space available for the iLife applications.
press the space bar
No because the Mac App Store requires Mac OS X 10.6.6 which is not supported on the old G3/G4 iBooks.
I do not think that you can because it just wont let you do that.
You can email out a PDF book to any computer, but you cannot transfer books you purchased on the iBook store to the Mac.
Like on other Apple computers, the command or "Apple" keys on the iBook G4 serve as part of many keyboard shortcuts. They can be used in combination with other keys when online or even for GUI applications.
Mac OS X 10.3.9 is nearly five years old (which is a long time in computer operating system years) the current version of Mac OS X is 10.5.7. The minimum requirement for the latest version of the Safari browser is 10.4.11. To update your browser you will need to update your version of Mac OS X. Mac OS X 10.5 (Leopard) will work on an iBook G4.
Select an icon with a single click and then press the space bar to activate a Quicklook window.