LCD and Touchscreen is non responsive

I have searched quite a bit on this one...hoping for some enlightenment. I apologize in advance for the length of the post, but trying to be descriptive as possible. My friend's daughter dropped her Iphone 3G in the street. Not sure if it got ran over or not, but most likely not. At the time, LCD was working, just cracked screen. I ordered screen/digitizer assembly. By the time it arrived, the IPhone's battery was dead, so no sense in powering down. Upon succesfully installing the new screen/digitizer and charging, the picture on LCD was very washed out, but functional. I assumed one of the connectors was not fully hooked on. I disassembled, check cables, reassembled. No screen at all. Did hard boot with home & power button. Alas! Screen reappeared, but all white :( no apple logo, no nothing, just snow white screen. Again, disassembled to check my cables again. Reconnected 1 & 2. Powered back up. Alas! Apple logo and full boot. Realizing I did not connect number 3 in the process, shut down again and was about to reconnected 1,2 & 3 cables. While putting in number 1, accidentally hit the power on button. I'm worried this had something to do with my current issues. Powered down immediately, continued connected cables and refired. Absolutely nothing. No white, no logo, just black. The mute switch is causing vibration and itunes is recognizing the phone, but absolutely no picture. Tried numberous hard restarts, cleaning connectors, unscrewing motherboard and separating from battery in an attempt to "reset" iphone and even tried a restore in itunes. Nothing. Still has vibration and sound, just no screen. Any ideas? All connectors look clean with no missing/bent or otherwise faulty looking connections. Any help is much appreciated.