Just upgraded Raspberri OS - afte r that DAC+ PRO no sound (green light turned off)
Linux raspi-audio 5.4.79-v7l+ #1373 SMP Mon Nov 23 13:27:40 GMT 2020 armv7l GNU/Linux
Karte 2: sndrpihifiberry [snd_rpi_hifiberry_dacplus], Gerät 0: HiFiBerry DAC+ Pro HiFi pcm512x-hifi-0 [HiFiBerry DAC+ Pro HiFi pcm512x-hifi-0]
Sub-Gerät #0: subdevice #0
Besides upgrade (sudo apt upgrade) and reboot I didn't change anything. Before upgrade everything was ok.