When you look into your settings you may have the case where you see 2 kind of similar names for your input device. They are not exactely the same . (I had the case with a Bose) , one is for stereo audio, and one for mono.
when i selected stereo, microphone would not work.
so try to look for this. You have to select MONO .. ( yes , somewhat related to the rings on the audio jack..)