Why can Xiaomi 1S only send text messages but not make calls when pressing the campus mobile 4G card?

Hello, 1. Please put the mobile phone card into another mobile phone and check whether you can send and receive text messages. 2. If you cannot receive text messages, please contact your network operator to see if there is a problem with the SIM card. 3. If you can send and receive text messages, it is recommended that you reinsert the card into your phone and send yourself a text message to see if you can receive it. 4. Please enter the SMS center and contact your mobile operator to check your SMS center number. 5. If the number is correct, please temporarily uninstall your system security software. 6. If the problem still cannot be solved, please back up your data and enter recovery. Clear cache, user data and all data, do not restore system settings after entering the system. I hope the above reply will be helpful to you. View original post>>