amixer settings are all unmuted and 100%. I'm not really even sure where else to look for this. My sound works otherwise.
Next step in troubleshoting this is to install pavucontrol and check that in Configuration tab you select Audio Stereo Duplex and then check the Input Devices tab check the mute button is pressed and check the volume and the metter there. With some luck you can find a configuration that will work for you. To install pavucontrol install the pulseaudio-utils package