audio and h d m i trouble

[Daniel Crone]

I have ubuntu mate 18.04.
After trying to configure mumble, linux no longer works with hdmi as far as audio.
I must use a usb sound card and speakers.
Yet h d m i works with the mate dvd.
So it is not the hardware.

I got the mate dvd, and typed the following.

cd $HOME
cd .config
rm -fr pulse

I thought that would fix my audio, so what might I be missing?