Lenovo Fn+F4 MicMute binding fix

Start ACPI service if not running:

/etc/init.d/acpid start

Run acpi_listen and hit the key kombination. Something like this should emit:

$ acpi_listen 
button/micmute MICMUTE 00000080 00000000 K

Create a file /etc/acpi/events/thinkpad-micmute and put this snippet into it (update event based on previous command output):

event=button/micmute MICMUTE 00000080 00000000 K                                
action=/etc/acpi/thinkpad-micmute.sh

Create a file /etc/acpi/thinkpad-micmute.sh and make it executable

$ touch /etc/acpi/thinkpad-micmute.sh && chmod a+x /etc/acpi/thinkpad-micmute.sh

Open it and put the following snippet into it:

/usr/bin/amixer sset Capture toggle

Restart acpid service

$ /etc/init.d/acpid start

also make sure it is being started after boot

systemctl enable acpid.socket