I have the same problem on a Toshiba a210. I was trying to install Elementary OS Loki when i found out.
Elementary Loki (16.04) with kernel 4.10 - Reboot and Shutdown doesn't work. Elementary Loki (16.04) with kernel 4.4 - Shutdown works, but reboot makes the Bios screen (toshiba logo) freeze. Ubuntu 16.04 liveusb with 4.4 have the same problem as Loki 4.4. If you press quickly the f2 button, after some time you see the hard disk led light up and the computer enters the boot screen, but when you try ctrl+alt+del it goes back to the freeze. Only the power button makes the problem go away. " https://forum.level1techs.com/t/ubuntu-16-04-hanging-on-reboot/112413 " This person seems to have the same issue, but on a HP laptop. Does anybody knows what could be causing the Bios screen freeze? Thanks. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1594023 Title: Poweroff or reboot hangs. Laptop won't shutdown. 16.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1594023/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs