Hello List,
from time to time I spend time on this problem. (Of course, it is not related to muting or capturing in alsamixer, or pulseaudio stuff, since that was already tried.)
I can't get the mics to work, neither the internal one nor the external; note that the same jack works both for HP and ext MIC, I think it's called TRRS, and it's the same as the one used e.g. on iphones.
I tried also with more recent kernels, and playing with hda-jack-retask, but with no success up to now.
alsa script result is attached
A curious fact, I found this alsa script result http://www.alsa-project.org/db/?f=3ca8243c0626844f0264a3faad0aa72018bc14f4 from a guy running Arch on the same machine, where actually some Mic appears in codec#0: do you think it is relevant?
Thanks and best, Nicolo'