Your iPhone is black but you know its on cause it vibartes?

My Iphone goes black and white and I kept banging it, Because it go back to normal. So when I was banging it It went black! But I knew it was on because I kept getting text messages and it vibrated and kept getting nonifications. But it still stayed black and I kept trying to find solutions on youtube. I found this man, and it happened to him also! So he said if it doesnt work go to iFixit.com. So I need this phone working by Friday. So I am hopeing that you guys can help me out! Please. 3/25/15.