hp pavilion dv7-1245dx screen wont turn on

I havent been on my computer in a few months because I lost my charger cord well now that I puchased a new one my screen wont turn on. I hear the whole thing start up but no screen power. I did the power reset unplugged it took the battery out for a bit and held the start button to make sure and tuened it on wirh again the same result. The only thing that seems to wirk are the keyboard lights and the capslock light it blinks 4 times stops and then repeats