The cell phone signal is full, so I can't make a phone call or answer it, and I can't answer it or send a text message. Why?

The common reasons and solutions that mobile phone calling cards can't answer calls are as follows:

[1] Check whether the mobile phone is in arrears, and suggest to pay for recharging;

[2] Check whether the mobile phone is set with call forwarding, flight mode on and call barring. Suggest canceling and try again;

[3] Check whether the function or signal of the mobile phone is normal, and suggest to change the mobile phone or try again;

[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;

[5] Try to restart or change the phone to see if you can answer the phone;

[6] Take the mobile phone card to the local business hall for testing or replacement.