Probably was looking for console, when in fact you were looking for Terminal, right
Do the following.
Open console (Terminal):
Run this command:
kmix
Set the volumes of all to max. And then try again (sound testing, not mp3 playing, as mp3 playing is not supported out of the box in FC2 due to some legal problems). For mp3 playing you need xmms, which I presume you have. And you also need this file to install before mp3 will work:
http://um-sd06-210-1.uni-mb.si/mp3_for_xmms.rpm
Good luck! You probably only have muted sound. Try playing something and at the same time try running as root in console:
cat /dev/dsp
This should produce a lot of data on your screen and show you what data your soundcard is recieving. Stop the output with CTRL+C