Comment 18 for bug 1359803

Experiencing same problem on Debian Jessie on Lenovo G40-30. After assigning pin 0x18 to microphone acpi_listen prints that microphone is plugged in but pavucontrol still shows mic as unplugged. Also trying to boost appeared after pin assignment microphone in alsamixer makes large increasing noise so I think overriding that pin is not a part of solution for me. Fabianbur's solution didn't work too.