There are two ways to connect, depending on the state of your box:
Method A: USB Cable (Recommended)
Method B: Recovery Mode (If Method A fails)
Unlike newer Amlogic chips, the S805 often requires a hardware short to enter Mask ROM mode.
Before downloading any files, it is critical to identify your hardware. The brand "MXQ" is generic; hundreds of manufacturers use this casing.
There is no single "universal" firmware for the MXQ S805. You must identify your PCB (printed circuit board) version. Open the box (four screws under rubber feet) and look for a silk-screened text on the board. Common versions include:
Warning: Flashing the wrong board version will permanently brick your device or cause Wi-Fi/Ethernet to stop working.
Choose the method that matches the files you downloaded and the box’s recovery capabilities.