My issue seems to have resolved in the last mainline update to kernel 4.4.0-57-generic #78-Ubuntu SMP Fri Dec 9 23:50:32 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux.
I have rebooted the computer several times to make sure the sound card continues to work and so far so good. If the issue returns I will reopen the bug report. Thank you for your all your help. ** Changed in: linux (Ubuntu) Status: Incomplete => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1649668 Title: PCI/internal sound card not detected Acer Aspire E5-575 Intel Corporation Device 9d71 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1649668/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs