Xiaomi's mobile phone can't make calls, send text messages or surf the Internet. What happened?

This is a problem with Xiaomi's mobile phone system, which needs to be upgraded to solve the problem.

The following are some considerations when upgrading the system:

1. Make sure that the computer is not turned off during the system upgrade, and the mobile phone is not turned off during the system upgrade, and the genuine USB cable is used.

2. When upgrading the system, the data cable is the key to data interaction. If there is something wrong with the data cable, it may affect the upgrade system. At the same time, be careful not to disconnect the data cable when upgrading the system.

3. Use the correct ROM package. This is very important. If there is something wrong with the ROM package, it is a terrible thing. It's like a super computer. If you bring a problematic operating system to install, it won't work well after installation or even can't be installed at all. So after downloading the ROM package, you must check it with a program like WINMD5 and compare it with the value provided by the ROM publisher. If it's different, don't use it.

4. Pay attention to the software prompts when upgrading the system. Whether it is an integrated package or a split package, the software will have detailed prompts during the system upgrade. After upgrading the system completely, proceed to the next step. Do not interrupt the upgrade process before the upgrade system is completed, resulting in an error.

5. Before upgrading the system, prepare an integrated software package that can work normally. If there is an error in the system upgrade, be calm and don't panic. Prepare a package that worked normally before. There is a problem with the new version upgrade system. Don't panic, just refresh it. If it really doesn't work, it's no problem to brush the one-piece bag you prepared.