Macbook Pro black(dark screen) problem

Can someone pls help me with this because i dont have the time to go all the way to an apple store.My Macbook pro early 2011(10.8.3) screen refuses to light up so i have connected it to an external Monitor. Does anyone know if its software related or hardware issue.i have tried changing the energy saving settings to no avail. i tried putting it to sleep and waking it again no use.I reset pram and nvram still nuthing.Help!!!!!!