I replaced the volume/vibrate/lock flex on my iPhone 5 and once I got it back together the phone is constantly "Searching" for the cellular network. Everything else works on the phone. I also noticed that when I eject the SIM card the phone does not display "No Sim" as it would normally. It is an AT&T iPhone 5. Does anyone have any idea what could have caused this? The cell antenna in the bottom right corner is not compromised and the interconnect cables are attached correctly. What else could cause this problem?