My phone has been unable to connect to a cellular network for a week now. The problem started after the battery died, after starting the phone again it was unable to connect to a cellular network and give the message "emergency calls only". The Sim card is recognized by the phone and does list the network provider in the "About Phone" menu.
It does not however list the number of the sim card. I did try the card in another phone and it had no issue. Additionally I restarted the phone tried the Sim card in the other sim card slot and when that did not work I also decided to do a factory reset as well.