What happened when Xiaomi's mobile phone 4 suddenly stopped ringing?

I suggest you check whether the data attempt is normal!

You can enter the recovery mode and directly clear the data.

The method is to back up important personal data first ~ then turn it off ~ hold down the volume button and the power button at the same time ~ After recovery, use the volume button to select, the power button to confirm, and select Clear Data, Clear Cache' to clear all data, which is Sanqing.

When restoring the backup, set the third-party security software in the mobile phone, do not restore it, and try it normally!

PS: The way to resume is to turn off the power first, and then press and hold the volume button and the power button. Once inside, the touch screen is useless. You must use the volume button to select the power button to confirm, select Simplified Chinese ~ Clear Data ~ Select Clear Cache, Clear User Data and Clear All Data.

Then choose to turn off, and then press and hold the power button to turn on.