I had 2 problems, the cellular connection would only work for 10 seconds before going into "searching" plus the phone would charge to 3 percent, die, and then repeat the procedure. What I did was I took out the battery, the tin plate above the 5 cables near the top of the phone, and lifted the dock connector. So I did not redo that much. I cleaned all contact surfaces as I had been told but chose to not do before.... I also took out the grounding clip by the battery connectors and bent it upwards quite a bit while also peeling away 2 mm of the black insulation material on the back of the phone to make sure the grounding clip connects well to the back of the phone. I also cleaned that surface with window cleaner, which is basically isoprypol alcohol as has been recommended. The cellular antenna connector I pushed down firmly to make sure it was connected, I was gentler the first time, now everything works. My amateur guess is maybe the grounding clip was not well connected.