No sound on Acer Chromebook R13

[Ektif]

Hello,

Half a year ago, I installed Arch Linux on an old Chromebook. I followed the instructions written here and unmuted the channels listed in the wiki, but with no success. Unmuting every channel didn't work either. Neither the Chromebook's speakers nor headphones work. Since it is a secondary device, it didn't really bother for half a year.

Since some time past, I unfortunately don't know any more, what other steps I might have tried.

I would be very grateful for any help.