No sound with RealTek ALC892

Every now and then my computer’s sound dies and my speakers only produce pops and clicks. I have a Biostar TA880GB+ motherboard with a RealTek ALC892 sound chip. I assumed the fault was with the driver and went on a quest to reinstall all of the audio-related stuff in my Fedora 15 install. Sadly, after much driver reinstalling and audio reconfiguring the speakers were still only emitting pops and clicks. I finally tried powering down the computer (who ever does that?) and now it works. I had rebooted several times – for some reason the system needed to be powered down completely.