Why can't I make phone calls but send text messages when I open international roaming?

Check the signal strength indicator on the monitor. If the signal is weak, move to an open position, if in a building, move to a nearby window. Check the network selection settings. Try to manually select or try another network. View the network operation area map. Show restricted calls? Check call barring, Fixed Dialing and Closed User Group Settings. Have you reached the call charge limit? Use PIN2 code to reset the upper limit or contact your service provider.