What to do when the HDMI audio device not plugged in?
a. Restart your Mini PC might help you solve this problem. ( Sometimes this issue happens when you change a TV set.)
b. If this is the first time you use Mini PC or when you change a TV set, please do as follow:
b-1. Connect your Mini PC to the TV with HDMI cable;
b-2. Turn on your TV and set video input as HDMI;
b-3. Power on Mini PC.