Warning: Please make sure that the laptop is not connecting to any power source including the battery and the AC adapter.
The Laptop LCD Screen
The Laptop LCD Screen is one of the most important (also expensive) parts for the Laptop. The LCD Screen itself has several components. There are several ways to identify which component is defective.
Problem: Laptop LCD screen was dark.
Solve: plug the laptop to an external monitor. If the external monitor displays normally, then the problem is from one of these components: LCD backlight, laptop inverter, LCD cable or video board. Further tests have to be conducted to verify the particular component.
First open the LCD to test the Laptop inverter, connect to a separate LCD back light (can purchase from www.computercare.ca), turn the computer on; if the backlight lights up, then the inverter is highly unlikely defective.
Laptop LCD Screen Repair Example
Model: Compaq Presario V2000
1. Please notice that by repairing the laptop LCD yourself, it could potentially damage your laptop permanently! Our demonstration is intended for person who has certain level of technical skills or willing to learn. Please read this installation instruction carefully BEFORE repairing.
2. If you think that it is better not repairing the laptop LCD yourself, we appreciate your decision. In reading this installation guide you agree to free us from any responsibility for any kind of damage, which might occur as a consequence of this laptop repair.
3. Please be aware that some of the original warranties that come with your laptop and the LCD screen could be void while you repairing. 

Step by Step with 19 pictures