It sure sounds like the LCD or the backlight. You'd surely want to check the connectors. Before you open it you could try to GENTLY squeeze the case edge all the way around the perimeter. If it changes it may indicate the cause.
When you turn it on do you see any change in the screen? If it's dead black then it could be the backlight. If there's some change (less black) it could be the LCD.
Hopefully it's just a loose cable and opening it and reseating will fix it.
Good luck.