I have a Toshiba Laptop, and my LCD screen would sometimes not light up...?

I have to tediously bring the screen up and down slowly until the back light will illuminate the screen. I am still able to see the display, however through a thick layer of darkness. Could it be a possibility that the activating on that lights up the screen is broken? Or is the LCD is worn, due to the fact that I did have the laptop for 3 years.