The LED screen in your Compaq Presario laptop is powered by a bulb that is located directly behind the screen. If your screen is dark or is generally not functioning properly, it is likely the result of a blown backlight bulb. The good news is that you don't need to pay a computer tech to fix the problem for you, as you can replace the backlight yourself.
1). Power off your F500 and unplug the AC adapter power cable.
2). Slide the rectangular battery out of its compartment located on the underside of the computer.
3). Open the display screen and use your Phillips screwdriver to remove all screws on the sides and corners of the plastic frame that surrounds the display screen.
4). Use your fingers to pry the frame off of the screen at the sides and corners.
5). Locate the rectangular inverter board mounted directly below the screen. There will be two wires plugged into ports on either side of the board. The wire on the right side of the board is the backlight bulb wire. Unplug it.
6). Tilt the screen forward to expose the backlight bulb secured to the rear of the LCD with tape. Remove the tape covering the backlight bulb and remove the bulb.
7). Fit a new bulb in the old one's place and replace the tape.
8). Plug the bulb cable into the port on the inverter board and replace the screen frame and screws.