If your keyboard is malfunctioning you can remove the keyboard to clean it. If that doesn't solve your problem you will need to replace the keyboard.
Close the screen and turn the PowerBook over. Orient the computer so the text of the label is right side up.
Press and hold the button on the left of the front side and slide the battery out.
With a T8 torx screwdriver, remove the three 24mm torx screws along the middle of the back panel.
Turn the computer over and open the display. You should see that the keyboard is loose.
Carefully lift the front of the keyboard up slightly and then slide the keyboard towards yourself.
Then carefully lift the top half of the keyboard and rotate it towards yourself.
Loosen the ribbon cables connecting the keyboard to the computer by using a plastic opening tool to lift the tabs on either side of the cable port.
Gently remove the ribbons from its tabs