The system is working now. I have been taking backups on the external drive connected to the 4-port hub it since yesterday. The backup (a large one) ran for several hours until late at night without a hitch. Since this morning the system has booted fine and has not shown any sign of crashing.
Thanks to Christophe Penalver for his detailed instructions on how to upgrade the kernel, I upgraded to a mainline kernel. The kernel is linux-kernel-4.0.0-040000-generic. I am marking the status of this bug as "CONFIRMED". I have also added the tags as suggested by Christophe. Thanks once again for all the inputs ** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1443764 Title: Black screen of death: system suddenly stopped working soon after upgrade to kernel 3.16.0.34-generic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1443764/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs