Thanks. If the sound worked fine in Ubuntu 16.04 then that's useful information. 16.04 used kernel 4.4 and you are presently using kernel 4.15
Next, please try installing an older kernel version and see if that fixes the problem. 1. Download these: http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.146/linux-headers-4.4.146-0404146_4.4.146-0404146.201808061143_all.deb http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.146/linux-headers-4.4.146-0404146-generic_4.4.146-0404146.201808061143_amd64.deb http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.146/linux-image-4.4.146-0404146-generic_4.4.146-0404146.201808061143_amd64.deb 2. In a terminal run: cd ~/Downloads sudo dpkg -i linux*4.4.146*deb 3. Reboot and hold down Shift at start-up to choose the different kernel version. 4. Now check the new kernel is active by running: uname -a and send us the output. ** Also affects: linux (Ubuntu) Importance: Undecided Status: New ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1786195 Title: broken audio/muffled, no system audio To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1786195/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs