ThinkPad microphone not working

[stan]

On Thu, 12 Apr 2012 23:34:39 +0200
suvayu ali <fatkasuvayu+linux at gmail.com> wrote:

> For the last 2 weeks the microphone on my ThinkPad has stopped
> working. At first I thought the volume levels must have gone down, but
> I see using alsamixer they are all normal.
> 
> I'm using F16. My understanding of alsa is rather limited, Anyone has
> any ideas how I can troubleshoot this?

I see a thread on the alsa-devel list about problems with sound on
Thinkpads with the 3.3 kernel.  It is only talking about playing having
problems, but perhaps it has also affected recording.  You could look
at it on gmane.org in the alsa-devel group to see if it has any
relevance to you.  The subject is
Re: [alsa-devel] Thinkpad hda regression in 3.3