Ensure that the mobile phone can be connected to the computer with usb data cable;

Install the flashtool software on the computer, open the installation directory folder to find the driver, and double-click the driver installation program inside to install the mobile phone driver (the system above windows8 needs advanced restart to disable the driver signature for installation);

Download the official rom firmware package, copy and paste it into the firmware folder;

According to the number of bits in the system, open the corresponding flashtool program, and which 64-character program to open in the 64-bit system;

Click the lightning mode-OK in the upper left corner;

Select the official rom firmware package just downloaded, and click OK;

The flashtool tool will decompress the firmware package and prepare to brush the machine, and a prompt for connecting the mobile phone will pop up later;

Wait about 10 second for the phone to turn off (if it can't be turned off normally, you can force it to turn off, press and hold the power button and volume up button on time, and wait until the phone vibrates for three times before forcing it to turn off). In the case of complete shutdown, press and hold the volume down button and connect the computer with the original data cable;

Flashtool shows that the mobile phone is connected, and it starts to brush. The mobile phone also has a green light prompt, so wait patiently for the end of the brushing process.

After the brushing process, disconnect the phone and start it. It takes a long time to start for the first time, so just wait patiently.