Last night all was well with my Ubuntu laptop and I shut it down as normal. This morning it hung on boot at the splash screen with 5 dots lit up. Reading posts here and there suggested I should just let the machine cook for 15 minutes or so (something like Windows and it’s pre-boot installations of updates). So I left it alone for an hour and no improvement. The disk activity indicator almost from the point of the splash screen slowed to once or so a minute for the entire hour. Nothing was happening and waiting any longer would be pointless.

I read up on the grub recovery mode and jumped into the grub menu (hold the Shift key down while booting) and selected Recover Mode and in the console hit Control-D to get to the login prompt.

There, I tried a few things always suspecting it was the monitor/xserver/display. Something about the display kept gnawing at me but I cannot say what it was.

I hit upon a writeup that showed this:

Booted into recovery mode and logged in on command line.

Checked everything was up to date, reinstalled gdm and xorg:
$ sudo apt-get update && sudo apt-get upgrade
$ sudo apt-get install --reinstall gdm xorg

Removed xorg.conf so that a new one was created upon boot:
$ sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.faulty
$ sudo reboot

This did work and after rebooting the only issue was I didn’t have the right display (NVidia) driver. It just so happened that a system update brought in the latest kernel changes and coincidentally gave me the right driver. I had to seek no further.

This took over 4 hours of my time to fix.