I'm not familiar with SuSE really, but here's something to try..
Open a console, get root permission, and type 'alsaconf' and follow the instructions.
If that worked, then now type 'alsamixer'.
With any luck, your alsa mixer panel will appear. Check the mixer settings present to make sure any devices present are not muted (MM) and that volume levels are not set to zero.
Use the arrow keys and spacebar to accomplish this.
When done, press escape to exit.
Type 'alsactl store' to save the settings.
Now, using KDE Control Panel or whatever you use to test the sound system, set the sound system to 'auto-detect' and save/restart the sound system, and test it.
Hope this helped