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.