My backlight isn't working now? Maybe I got it too hot?

I had an 4th gen white screen that I needed to get rid of. Tried putting it on a black iPod, nothing wrong with it except cracked screen. Even took a pic with the camera and worked great. I used a hair dryer to heat the adhesive. Do you think that is the source of the problem that my backlight isn't working now? Maybe I got it too hot? Any easy fix for that? Its pretty annoying that it was working an hour ago and its not now. Any chance its the actual replacement assembly?