A) Suggest you start with seeing if graphics are being shown, but not displaying on the LCD screen.
May be an Inverter problem.
1) Laptop on, use a flashlight, and shine it at the LCD screen. Shine the flashlight at an angle.
Do you see faint images?
2) Laptop off, plug in a VGA monitor to the VGA connector on the back of the laptop. Turn the VGA monitor on, and turn the laptop on. (Do NOT have the laptop running, and plug the monitor into it)
This is what a VGA connector looks like,http://en.wikipedia.org/wiki/VGA_connector
(Photo to the right. The VGA monitor cable's connector is shown to the Left)
Press the Fn key, hold it down, and press the key that toggles over the graphics to an external monitor. The key will have a monitor icon symbol on it. (Empty rectangle)
Do you have graphics on the External monitor?
1) expounded on:
An LCD screen cannot produce enough light by itself.
For this reason an additional light source is provided.
A Backlight is the additional light source.
A Backlight is a CCFL.
Cold Cathode Fluorescent Lamp. (Lamp = Bulb)
Similar to Fluorescent lighting used in homes, and businesses, but on a MUCH smaller scale.
An Inverter is used to provide power for the LCD screen, and the Backlight.
The laptop's power is not enough to power the LCD screen, so the power is increased for the LCD screen by the Inverter.
The power from the laptop is too much for a Backlight, so the power is decreased for the Backlight by the Inverter.
90 percent of the time the problem is the Inverter, not the Backlight.
An Inverter is a small circuit board located within the Display Assembly.
The Display Assembly consists of;
1) The top panel of the laptop that you see with the laptop closed.
2) The LCD screen (Assembly. More on that in a minute)
3) The Bezel. The thin frame in front of the LCD screen, that surrounds the LCD screen. Looks like a 'Picture Frame'
4) The metal frame that holds the LCD assembly together, and it's screws.
5) The brackets that are screwed to the LCD assembly frame, and then the brackets are screwed to the top panel.
6) The Inverter. A small circuit board, (Usually as long as your longest finger, and about the same width), located BEHIND the Bezel, and at the bottom of the LCD screen
7) Wireless Antenna
8) Backlight. Description already provided. The Backlight is inside the metal frame that surrounds the LCD assembly. On one edge. (Sometimes more than one Backlight is used)
The LCD screen is an assembly. What you see on the outside is a protective screen.
If I may;http://solutions.3m.com/wps/portal/3M/en_US/Vikuiti1/BrandProducts/secondary/optics101/
This is an example of an Inverter for an Everex Stepnote VA4300M,http://www.laptoprepairparts.com/html/details.asp?ref=1048&category=inverter
I await your findings. Post in a Comment.