Could you clarify the exact manufacturer or the type of device (e.g., Android TV box, smart home hub, or AV extender)? Nortek Software
6.3 Bootloader-mode recovery via USB/serial/TFTP
The High-Definition Multimedia Interface (HDMI) protocol relies on continuous communication between your playback box and your television or projector. This communication protocol is managed directly by the device's firmware. Common Signs You Need a Firmware Update
Confirm EDID reading and HDCP states in logs.