What is wrong with my macbook pro late 2006?

I used it earlier today it worked fine. Went to college came home used macbook it worked fine aswell. 2 hours later I turned it on heard fans power button was white but no display. It isn't in warranty.I tried to reset the ram,same. Take out the battery & charger then press power button for 30 seconds turned it back on same display problems. I have an appointment with the genius bar tomorrow. What do you think could be wrong?