Sound issues in Lenovo C940 Yoga

I’ve followed the instructions in the Arch wiki in regards of enabling audio for my machine. Currently. when I run inxi -Fxxxx, it shows

  Device-1: Intel Ice Lake-LP Smart Sound Audio vendor: Lenovo
    driver: sof-audio-pci bus-ID: 00:1f.3 chip-ID: 8086:34c8 class-ID: 0401
  Sound Server-1: ALSA v: k5.6.15-1-MANJARO running: yes
  Sound Server-2: JACK v: 1.9.20 running: no
  Sound Server-3: PulseAudio v: 15.0 running: yes
  Sound Server-4: PipeWire v: 0.3.48 running: yes

for audio, but when running pactl list sources, there is only dummy output:

~ >>> pactl list sources                                                                                                                                  
Source #0
        State: SUSPENDED
        Name: auto_null.monitor
        Description: Monitor of Dummy Output
        Driver: module-null-sink.c
        Sample Specification: s16le 2ch 44100Hz
        Channel Map: front-left,front-right
        Owner Module: 15
        Mute: no
        Volume: front-left: 65536 / 100% / 0.00 dB,   front-right: 65536 / 100% / 0.00 dB
                balance 0.00
        Base Volume: 65536 / 100% / 0.00 dB
        Monitor of Sink: auto_null
        Latency: 0 usec, configured 0 usec
                device.description = "Monitor of Dummy Output"
                device.class = "monitor"
                device.icon_name = "audio-input-microphone"

Any ideas?

Welcome to Manjaro forum

Comments on Archwiki and Bugzilla report from last year suggest that if the BIOS is updated for Yoga C940-14IIL the 4 audio speakers work correctly without additional reconfiguration
But the BIOS update suggested does not work for Yoga C940-15IRH

I suggest you check the model number and firmware version of system

inxi -Mazy

and find the latest BIOS update available from Lenovo support

Once the BIOS is up to date I suggest you boot system from a USB Live ISO to check if audio works without any reconfiguration
If audio is working on Live ISO, changes made to installed OS can be reverted

If audio is not working on Live ISO, get a full ALSA diagnostic to show audio hardware configuration

sudo --upload