I just bought this Dell Inspiron N5020 laptop, and the audio works fine (if a bit low in volume with all the mixer levels at 100%) but when I plug in the headphones the music cuts off entirely and doesn't come in through the headphones, and in addition the mic jack doesn't work at all. I'm running Linux Mint 9 Fluxbox.

I've tried changing the "model" variable in /etc/modprobe.d/alsa-base.conf to a bunch of different options (dell, fujitsu, base, auto) and the mixer slides change and do different things, but at no point do I ever get the headphones to work properly (on one model, I think "dell", the sound still came in through the laptop speakers even after I've plugged the headphones in).

The manual lists the audio controller as "Realtek ALC296Q-VB5", lspci lists it as

and uname -r gives the kernel as "2.6.32-22-generic".

I fear that the audio controller is some newer mutation of the ALC269 that isn't fully supported by the Linux driver, but if so I'd like to know for certain. I've done a lot of googling about this today and nothing has helped, though I have found a lot of forum posts about the Realtek audio devices not working entirely and a lot of fixes for other situations very similar to mine, but involving slightly different devices. Thanks in advance, and sorry if I haven't listed enough information.

Somewhat interesting new development... I tried "snd-hda-intel model=generic" for the first time and now audio comes out of my headphones, but not the speakers. I tried recording some audio in Audacity, and it recorded my voice faintly amidst a ton of static.