asus_zenbook_ux3402za

You must disable Secure Boot from BIOS before attempting this fix. Also, Secure Boot must remain disabled afterwards for the sound to continue to work.

Steps for the sound fix:

Edit ssdt-csc3551.dsl if needed (optional)
Build it

iasl -tc ssdt-csc3551.dsl

Copy it in /boot

sudo cp -f ssdt-csc3551.aml /boot

Copy grub script

sudo cp -f 01_acpi /etc/grub.d

sudo chmod +x /etc/grub.d/01_acpi

Update grub config
- Debian / Ubuntu based distributions
  
  sudo update-grub
- Fedora / RHEL-based distributions
  
  sudo grub2-mkconfig -o /etc/grub2.cfg
  
  sudo grub2-mkconfig -o /etc/grub2-efi.cfg
- Arch based distributions
  
  grub-mkconfig -o /boot/grub/grub.cfg
reboot