The screen went black after the first use,what happened?

After installation everything with the phone worked fine, but while using the phone today, all of a sudden lines went through the phone and it went black. I restarted the phone and took the battery out, but the screen won't illuminate. The touch screen digitizer works perfect, as well as the bottom keys are illuminated. Don't know if the screen was defective or not? Phone has never been dropped or anything and the screen is in perfect condition. Please Help!