When I boot up, I keep getting an error message telling me that my sound card isn't working, so the system is going to the Default. The exact message is:

The audio playback device HDA Intel (ALC269 Analog) does not work. Falling back to Default.
I'm using an ASUS laptop (UL80JT), 64-bit, with a low-latency kernel. I removed Pulse Audio because it was causing problems. After I did this, things worked for a while, but now they're messed up. I'm using ALSA.

When I Googled for an answer, I got:

"Через настройку параметров системы сделайте основным устройство default..."

Which isn't as helpful as it may first appear.

What's going on? Is there some tutorial or other source of information that explains how sound works (or doesn't work) in Linux, especially in Kubuntu?

Is it a missing driver or something? If so, how can I find it?

I'd be grateful for any help anyone can offer.