You will need a compatible ROM file (usually in .img format) specifically designed for the B866V2 model. Step-by-Step Unlock Methods 1. Software-Based Firmware Flash (The "Free" Method)
This method is commonly used to replace the carrier-restricted OS with a global or modified version that has and ADB access enabled by default.
While holding the physical reset button on the box, connect it to your PC using the male-to-male USB cable.
Required for connecting the TV box to your PC for flashing.