I will put pictures up in approximately 9 hours. I tried to take photos with my work phone (samsung rugby) and Bluetooth them to my iPhone 4 but will not pair. The only reason I know this problem could happen is from iphone 3's I have done. What I can do is provide a link to that website to help get you in the right frame of mind. Also I do not know what the resistor is used for and why it works with the circuit bypassed, it just does. I have two 3g's with this bypassed and have been working just fine for a year now with no issues. It might might use more battery, but it's only been a day and I could just be paranoid. My next post will be the link if I can find it.
I found the solution!!! I too replaced a digitizer on my iPhone 4 only to put it back together and find "no service". From the silver connector, trace the circuit towards what looks like a copper connector of the same type. In between the two male connectors, is a very very small resistor. It is either blue or purple in color (or is probably missing already). Bump it with a screwdriver and see if it moves. I spent 10 hours finding this out. I tapped the resistor, and it fell off. I joined the connection points together with a low temp solder and got full 3G service!