There is no sound. Dummy output

AFAIK Apple systems use mostly Cirrus Logic audio codecs (CS4206/4207/4208)

Workaround using hda-verbs has been confirmed to work on Asus notebooks with Realtek ALC294 codec
Dual boot: Weird no sound behavior but devices are visible - #4 by nikgnomic
Headphone not working - #8 by nikgnomic
There have been no further issues reported with Asus ALC294 systems since April, so I suspect this audio codec has been patched in kernel by ALSA developers