Originally Posted by eon
Try "lsmod|grep sound" in a shell/terminal and see if your sound is indeed recognized
(note the vertical line i.e. pipe symbol is produced by typing "shift key plus the \ key).
If it is then you might try alsamixer to see if the sound is muted (you may need to set the volume levels).
KDE has a sound and devices GUI in the system menu which can be used to test sound after you make changes.
If nothing works up to this point try doing
"/etc/init.d/alsa restart" or /etc/init.d/alsa -autoconfig" in a terminal.
If none of that works just copy and paste the error messages to this thread. Good Luck!