Below USB tool is required when flashing firmware (could get from V-Tek):
Wire as below: (DO NOT CONNECT to PC at FIRST)
a. Unzip “IX850_AutoWriter.rar” and run “AutoWriter.exe”
b. when you see below window, “Plug USB and power-on to start programming” and now connect the USB wire to your PC (Don’t need to power up the unit.). After the USB connected, wait for seconds the device will automatically write:
c. With below massage the write is finish.
For more details, please check the video by this link: https://1drv.ms/v/s!ApVgqTKy9CI-h2ygJZehbsjCHugU?e=Cd2pu8