Help -- no audio device

[John Aldrich]

My F11 box was working fine until I just recently discovered that audio no 
longer works. When I try to play audio using XMMS it says it can't open the 
audio and to check the output device, etc. The output device for XMMS is 
set to ALSA. My physical hardware is the onboard NVidia audio, which was 
working up until recently (not sure when it broke -- I don't listen to a 
lot of audio on my linux box.)

Any ideas what to check? All mixers are configured to use the hardware 
output.