Here is how to get the Fn F6 and Fn F5 keys working on a brand new 2017 Thinkpad X1 Carbon.
I switched to a new laptop, and noticed that the volume down key stopped working. I had rsynced all the files in my home dir to the new laptop, and it turns out one of these needs a tiny change.
Earlier, I wrote how to get the multimedia keys working on a Thinkpad T400s. That configuration file depended on using ALSA, but meanwhile Debian switched to PulseAudio, so the configuration needed updating.
A 4 line mini howto “get the multimedia keys working on a Thinkpad T400s”. This laptop is running Debian Sid, yet this will work for other distro’s too.