While holding the button, connect the TV box to your PC using the USB A-to-A cable (usually the port closest to the SD card slot).
: Repositories like MattWestb's GitHub provide device tree files and technical parameters for specific R29-MXQ-LP3-V2.3 builds. Common Use Cases R29 Mxq Lp3 V2.3 Firmware
Most of these boxes hide a physical reset button at the bottom of the 3.5mm AV port. You often need to hold this button with a toothpick while plugging in the power to enter "Maskrom" or "Loader" mode for flashing. Alternative Software: Armbian and Linux While holding the button, connect the TV box