USB flash drive upgrade steps and precautions:
1. Prepare a USB flash drive in fat32 format;
2. Put the USB flash drive upgrade package (update.zip) into the root directory of USB flash drive;
3. Insert the USB flash drive into the machine and wait for about 20 seconds.
An upgrade window will pop up on the interface.
1. Do not unplug the USB flash drive during the upgrade process. The machine should not be powered off.
2. Fat32 format is required for U disk;
3. The upgrade package cannot be identified until it is placed in the root directory of the U disk;
4. Make sure the power is above 30%, otherwise the upgrade may be unsuccessful;