Comment 26 for bug 580183

Here's a workaround. Works 100% with my Fedora, 2.6.33.x and alsa 1.0.23.

1) Get hda-analyser: http://www.alsa-project.org/main/index.php/HDA_Analyzer

This cute thing lists all pins, channels, etc'.

Run it and go to the 0x1a pin: unmute it (untick both)! That will ... unmute it.

2) Select "Audio Mixer [0x0c]" instead of d. That will assign the port to your output instead of input.

3) Reboot.

You can also try hda-verb as suggested above, but you'll still need to unmute the channels, you can get it in http://kernel.org/pub/linux/kernel/people/tiwai/misc/hda-verb/.

Cheers!