Had the same problem when moving from a RPi to a mini PC, and solved the problem using this external dongle: https://www.pulse-eight.com/p/104/usb-hdmi-cec-adap

Had the same problem when moving from a RPi to a mini PC, and solved the problem using this external dongle: https://www.pulse-eight.com/p/104/usb-hdmi-cec-adapter https://www.pulse-eight.com/p/104/usb-hdmi-cec-adapter Unfortunately it's not cheap, although the same functionality could be offered by a USB equipped small microcontroller "sniffing" 2 wires from a pass-through HDMI port.