Replaced LCD and phone worked but ear, checked cables now no power

I have an iPhone 3G that had a shattered screen and LCD. I bought replacement parts and did the repair. Everything seemed to be working until I made a phone call and could not hear from the ear piece, only sound would come when put into speaker mode. I read that maybe connector 3 was not fully seated so I went back inside the phone and tried to re-position the connector, now the phone will not turn on. I plugged it in and even after awhile of "charging" it would not even vibrate when the switch was moved. Does anyone know what may have happened, and what I can do?