1) Take a flashlight and shine at the LCD screen at various angles. See if there are faint images.
If faint images are seen the problem most likely will be the Inverter.
An LCD screen cannot produce enough light by itself. There needs to be an additional light source.
The additional light source is a Backlight.
A Backlight is a CCFL
Cold Cathode Fluorescent Lamp
Similar to Fluorescent lighting used in homes, and businesses, but on a Much smaller scale.
(A typical Backlight is varies in length, and is usually half the diameter of a No.2 pencil.
Example of a typical Backlight,http://www.buy.com/prod/new-15-inch-ccfl-backlight-for-toshiba-satellite-a55-s106/q/sellerid/23962916/loc/101/212931234.html
In the example given there are 9 Backlights shown. Click on the Backlight images to enlarge)
An Inverter is used to change the power from the laptop, and provide power to the LCD screen, and Backlight.
90 Percent of the time the Inverter is bad.
An Inverter is a small circuit board, and is located behind the Bezel, and usually at the bottom of the LCD screen.
(The thin plastic 'frame' going around the front of the LCD screen, is the Bezel)
If faint images are seen with the flashlight, replace the Inverter.
If you post the laptop's manufacturers name, and Model Number in a Comment, I may be able to give you a link to a free Service Manual detailing how simple it is to replace an Inverter.
I could also give links to possible choices for an Inverter.
(The Model Number is on the bottom of the laptop)
2) If no faint images are seen there is a problem with the graphics.
This could be due to something as simple as a Display Video Cable, or the graphics chipset itself.
(Not so simple)
The Display Video Cable comes from out of the body of the laptop, and usually runs next to one of the hinges. It then leads up into the Display Assembly, and attaches to the back of the LCD screen.
Constant opening and closing of the laptop may have damaged the cable, or could have sightly unplugged it.
The first thing to try would be to see if the cable's connector has come loose.
The next thing would be to check the continuity of the cable, and if damaged replace the cable.
(The continuity of the cable can be checked with a multimeter set to OHM's. An economical multimeter can be purchased for as little as $10 to $12)
There is also a Display power cable that goes to the Inverter. With some laptop models it is incorporated into the Display Cable. This cable can be damaged by opening, and closing the laptop repeatedly, or become loosened, and slightly unplugged.
(Some laptops are designed where this is never a problem. Other laptops are designed where this can be a frequent problem. Poor engineering design)
2A) There are some laptops, specifically the HP Pavilion dv2000 series, dv6000 series, and dv9000 series that have a problem with the graphics chipset is overheated.
Poor cooling design inside the laptop.
This explains more about it,http://www.youtube.com/watch?v=bnkQNmKauEc
For questions please post in a Comment.