Apple 6 mobile phone has a signal, but it can't make a call and can't answer the phone. What happened?

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

1, check whether the mobile phone is in arrears, and suggest paying 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. It is recommended to change your mobile phone or location and try again.

4. Try to restart or change the phone to see if you can answer the phone;

5. Bring the mobile phone card to the local business hall for testing or replacement.