How to change secret security? I can't get the message.

"It is recommended to operate according to the following methods:

1. Restart the phone to see if there is a signal problem.

2. Settings-Application Manager-Swipe Screen Options (All)-Find Information-Click Enter and try to clear the data.

3. Try to replace another SIM card.

4. Check whether the mobile phone is equipped with security guards or third-party SMS software, and test it after unloading.

5. Back up mobile phone data (phone book, SMS, multimedia files, etc.). ) and restore the factory settings.

If the above method still fails, please send the machine to the service center, and the engineer will check and deal with the machine. "