Dell Studio 15 showing blank screen after start

Hello,
I have a problem in my DELL Studio 15. It is turning on and screen is blank and black its not showing anything. My laptop was running well and suddenly this problem occurred. I can see I turned off the laptop forcefully, and from then I am facing this problem. My hard disk is running and indicator light is also glowing showing that system is on. Please help me and give me any solution from which I can turn my laptop properly again and do the works again properly. Thank you,