Hmm, okay...as root, type alsamixer -c0
Third item there is FMTX Fun. Turn that ON and then try the above steps again. Does that work?
If not, go back into alsamixer -c0 and see that FMTX Fun is ON and the next item after FMTX Fun, called Line DAC, is not muted. Try to increase the level of Line DAC to 100 and see if that helps

Again, make sure you are playing some music while doing this all the time.