iphone 3g isn't working, LCD problem I think?

[emmitt]

I broke my LCD screen on my Iphone 3g a few days back and ordered a new screen. Once I put it in today the phone would turn on but the screen would stay black. When I plug it in to itunes it recognizes it and and then commence syncing, so it's not the battery. I made sure the screen is connected too.. I'm pretty sure, kinda an amateur at fixing phones. But does anyone have any insight about this. anything would be appreciated