Xiaomi's mobile phone can't activate the sim card and can't receive short messages.

I suggest you go to Sanqing data to see.

Back up the data in advance (by opening Xiaomi's own backup tool ~ Create a new backup), enter the recovery mode, clear the cache, clear the user data, and clear all the data. When restoring the backup, do not restore the settings and third-party security software in the mobile phone. Try to use it normally.

2. 1. I suggest you put this mobile phone card in another mobile phone to see if you can surf the Internet. 2. If you can't access the Internet, please ask the operator whether it is a mobile phone card. Or ask the customer service staff to help you refresh the traffic. See if it's normal. 3. If you can use it, please put it into Xiaomi mobile phone, turn on the data stream switch and try to connect to the Internet.