I have been trying to get a TV card and mplayer to work on ubuntu 16.04. I get the picture but no sound. I opened System Settings / Sound and clicked on "Sound Test" then clicked on "Front Left" then on "Front Right" but get no sound at all. When I use VLC to play a video or music the sound is good.
My monitor is connected via an HDMI cable but the HDMI sound is muted.The speakers are plugged into the on-board sound device.
How do I get the "Sound" app to function properly ?