What should I do if the SMS is set to fail to connect?

The common reasons why mobile phones can't answer calls and their solutions are as follows:

Method 1: check whether the mobile phone is in arrears, and suggest paying for recharging;

Method 2: Check whether the mobile phone is set with call forwarding, airplane mode on and call barring. It is recommended to cancel and try again.

Method 3: check whether the function or signal of the mobile phone is normal, and suggest changing the mobile phone or trying again;

Method 4: If roaming to other places can't be used, it is recommended to check whether the local network signal is normal and whether roaming permission is enabled for this number;

Method 5: try to restart or replace the mobile phone to see if you can answer the phone;

Method 6: Take the mobile phone card to the local business hall for testing or replacement.