You need the exact firmware file for your hardware version (B866v2). Do not use v1 firmware on v2.

: Ethernet, Wi-Fi, and Bluetooth for peripheral support.

Connect the box to your PC while holding the reset button (or bridging the hardware points). Once the tool recognizes the device, click to begin the flash. Important Warnings Carrier Passwords

It is a complex, risky process with limited reward. You are better off buying a cheap, open Android TV stick (e.g., Xiaomi Mi Stick, Chromecast with Google TV) unless you enjoy technical tinkering.

Because these devices are often locked at the firmware level (ADB disabled, Developer Options hidden), unlocking them can range from simple software "bypasses" to complex hardware-based ROM changes. 1. The "Software Jump" (No Flashing Required)

sendcmd 1 DB save sendcmd 1 DB reboot