Alsa error, again

Hey @AudioPete,

The HiFiBerry Digi+ Pro is not being detected by the Raspberry Pi 4 Model B Rev 1.4 in your setup. This is confirmed by:

  • Absence of address 0x3b in i2cdetect -y 1
  • Kernel failure to probe WM8804 (error -121)
  • ALSA does not register sndrpihifiberry audio device

Critical facts:

  • Your Pi is Revision b03114, which corresponds to Raspberry Pi 4 Model B with 4GB RAM, not the newer Rev 1.5 model associated with known power sequencing issues

  • You confirmed the DAC is a genuine HiFiBerry Digi+ Pro

  • The I2C bus is completely empty, suggesting:

    • The WM8804 chip is not powered
    • Or is not connected correctly
    • Or has failed electrically

From various web sources:

  • Known issues exist with HiFiBerry Digi+ Pro and cold boot detection, but these mainly affect Pi 4 Rev 1.5, not your Rev 1.4
  • Full absence of I2C response is not typical of the cold boot issue, which tends to be intermittent

Most Likely Cause:

  • Hardware-level failure or poor connection of the Digi+ Pro to the GPIO header
  • Possible board damage or solder fault, especially around the I2C lines

Recommended Next Action:

  • Power down
  • Reseat the DAC carefully
  • Recheck GPIO alignment and contact
  • If still not detected by i2cdetect, test the DAC on another Raspberry Pi (if available) or replace it to confirm failure

This is not a software configuration issue; hardware is not responding at the electrical level.

Also, try running rpi-eeprom-update as outlined in this Volumio guide, as there is a chance that boot timing issues are affecting DAC detection.

Kind Regards,