Another observation to add to the above. I switched on the laptop from cold. It seemed to boot up correctly and the Speakers (Built-in Audio) were showing in the "Play sound through" panel of System Settings > Sound > Input. I started to play a video through the Videos app and noticed a slight crackling, the sound playback becoming intermittent. I then switched on a pair of Bluetooth headphones and, since Bluetooth was on by default, the headphones immediately connected and started playing the sound track. I then looked at the System Settings > Sound > Input panel and found that, although the Headset was listed under "Play sound through", they were not highlighted; the Speakers remained highlighted instead even though the sound was coming through the headphones. Using the trackpad to click between the two caused the sound output to be switched between Speakers and Headset. (The sound playback has remained clear and free from crackles since then and continues to play correctly whilst I am typing this comment using Firefox web Browser.)
The mystery deepens. Perhaps someone who understands the kernel operation knows where the bug lies. I do hope so. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1402194 Title: PCI/internal sound card not detected To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1402194/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
