Phone was working fine, then suddenly, would not make phone calls. SIM status says I am Disconnected from the Mobile network state, Out of Service from Service state (keeps switching from In service) , have 0 signal strength (that comes and goes), an Unknown Mobile voice network type, Unknown Movile data network type, and Not Roaming under Roaming. A duplicate phone purchsed the same day and on the same plan is working fine. No settings were changed by the user.