After the Android phone returns to the factory, you can't answer the phone, you can only dial outside.

This situation is usually because there is no wiping and double cleaning after the factory is restored. Or there is no automatic double clearing after the online ota upgrade of the mobile phone, which leads to the confusion of the system cache, so the error is reported.

Wiping (double cleaning) operation is recommended.

Wipe will delete all the settings of the mobile phone and all the installed programs and related files, and restore to the factory settings, that is, only the original state of the mobile phone will be obtained.

The steps of double wiping are as follows:

1. Press the HOME key+power key to enter the recovery mode.

2. Use the volume down button to select Erase Data/Restore Factory Settings.

3. Press the HOME key to execute the command of erasing data/restoring factory settings, then use the volume reduction key to select Yes-delete all user data, and press the HOME key to execute the command.

4. After executing the Yes-delete all user data command, it means to start execution.

5. Press the volume down key to select the command to erase the cache partition, and then press the HOME key to execute the command.

6. After executing the command of erasing cache partition, press the volume key to select Yes-Erase cache, and then press the HOME key to execute the command.

7. After executing the yes-wipecache command, it means that erasing the cache partition has also been successfully executed.

Select Restart System Now to restart the system after successfully erasing data/factory reset and erasing cache partition.