If the display is merely dark, turn on the computer and shine a flashlight to see if you can see the desktop or Apple logo. If you are able to faintly see the desktop, you should replace the [http://www.ifixit.com/iBook-Parts/iBook-G3-or-G4-Display-Inverter/IF150-043|inverter] to solve your problem. If the display is lighting up but does not display anything normally, I would plug in an external display to see if anything displays. If the external display appears to have issues similar the laptop's LCD, then you will need to replace your [http://www.ifixit.com/iBook-Parts/iBook-G4-12-Inch-1-2-GHz-Logic-Board/IF183-010|logic board]. If the external display appears normal. Please comment here regarding the exact anomalies on your laptop's LCD.
If the display is merely dark, turn on the computer and shine a flashlight to see if you can see the desktop or Apple logo. If you are able to faintly see the desktop, you should replace the [http://www.ifixit.com/iBook-Parts/iBook-G3-or-G4-Display-Inverter/IF150-043|inverter] to solve your problem. If the display is lighting up but does not display anything normally, I would plug in an external display to see if anything displays. If the external display appears to have issues similar the laptop's LCD, then you will need to replace your [http://www.ifixit.com/iBook-Parts/iBook-G4-12-Inch-1-2-GHz-Logic-Board/IF183-010|logic board]. If the external display appears normal. Please comment here regarding the exact anomalies on your laptop's LCD.
If the display is merely dark, turn on the computer and shine a flashlight to see if you can see the desktop or Apple logo. If you are able to faintly see the desktop, you should replace the [http://www.ifixit.com/iBook-Parts/iBook-G3-or-G4-Display-Inverter/IF150-043|inverter] to solve your problem. If the display is lighting up but does not display anything normally, I would plug in an external display to see if anything displays. If the external display appears to have issues similar the laptop's LCD, then you will need to replace your [http://www.ifixit.com/iBook-Parts/iBook-G4-12-Inch-1-2-GHz-Logic-Board/IF183-010|logic board]. If the external display appears normal. Please comment here regarding the exact anomalies on your laptop's LCD.