laptop turns on, screen black, won't turn off

Hey so I have a sony vaio laptop, I usually never have problems with it until recently when I turned it on and it displayed nothing. There is only a black screen but the Power light is on and I can hear the fans running. Whenever I click keys like capslock there's no light. I cannot turn it off unless I take out the battery and put it back in. I've tried hard resetting it but that doesn't work either. I've also tried flashing a light at the screen at different angles to see if there's a problem with that but there's nothing, it's purely just a black screen. please help, thanks.