Not charging or turning on after repair.

Also, make sure the "contact bracket" that sits beneath the battery at the connector is properly installed. It makes contact when back cover is installed.

I had a similar problem. This may help someone. After a screen replacement the iphone 4 would just shutoff and only power up when connected to a power source. I opened it back up and re-seated the battery connector. Everything worked fine, only to have it happen again within an hour or so. After the third time of this happening, I finally noticed a very small area on the battery connector cable where maybe it had been bent or twisted too much, and a section of wire was exposed. I put a small strip of electrical tape over the exposed wire and it has been functioning normally ever since.

I installed mine , and it didnt charge. I took it apart again and i found that i did not install the top of the connector in all the way. it even looked a little weird when i put the plate back on, on top of it. it looked liked it didnt sit properly. it wasnt lined up correctly from the bottom up. so i re-set it from the top down and Bingo, where charging.

Timo

Having resoldered the 4 battery connector pins (1 using a jump wire because the soldering pad got off when the connector detached from the board), I got the phone to turn on but the battery wouldn't charge either.

I finally seem to have solved the problem, which for me seem to have been that the 2nd connector was grounded due to the small prong connecting the back case: i inserted a plastic sheet in between to prevent contact and seemed to have done the trick =) also be careful that the metal plate covering the battery side connector doesn't come in contact with any of the newly soldered contacts.

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.