iPhone 4 screen display problem! Help needed!

I Broke my iPhone's front screen and the touch screen would not work... i repaired the screen with a new Digitizer/LCD screen replacement. After i finished putting the iPhone back together i powered it. The front screen came on but you could only see white light and not make out what was on the screen. I even got a call while it was like this i was somehow able to answer it by sliding my finger across the bottom of the touch screen how you would normally answer a call. so this mean the touch works but the display doesn't?

Does anyone have any suggestions to what might be the problem.