Bart van Deenan's solution worked for me under Ubuntu 16.10 but under 17.04 it seems to no longer fix the issue and headphones produce no sound.
Dell XPS 15 9550 Ubuntu 17.04 4.10.0-20-generic -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1575078 Title: [XPS 15 9550, Realtek ALC3266] Headphone jack stops working after a while To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1575078/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
