I'm having a bit of a problem getting my onboard sound card working. I'm running Debian with GNOME as the window manager. The card is being detected by the system (at least according to lspci), but there is no output whatsoever. I've tried changing the sound server to ALSA, artsd, OSS (default), and even ESD with no luck. This is what I'm getting from lspci in regards to audio:

0000:00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 50)

Volume control resets to zero if I try to adjust it, and any application I try to change sound options in says that there are no sound modules.

Odd thing is, I never had this problem in SuSE, Red Hat, Slackware. Thanks for any information you can provide.

I have exactly same chipset and ALSA works wonderfully. With Debian Sarge. Did you follow all installation instructions? Any weird behavior when running alsaconf?

Well, I've tried switching to ALSA through the GNOME control center, tested it, and got the message, "Failed to construct test pipeline for ALSA - Advanced Linux Sound Architecture" Every time I use alsaconf, no sound card (PnP, PCI, or Legacy) is detected.

However, if it matters, I did re-install ALSA after aptitude decided I didn't need it and took it off. The sound didn't work before that, anyway.

ALSA worked for me at once, so I never went into it in depth.
I can describe how I installed it, maybe it helps.
I installed base system, then added ALSA using apt-get. As far as I recall alsaconf was executed by install. Since there is conflict between kernel sound modules and ALSA, easiest method is to reboot. During this next boot existing module is blacklisted and alsa module loaded instead. That did it for me. Later I added alsa-oss, X and Gnome, but this is really not relevant.
Setting BIOS setting to pnp-os = no is a good idea too.