This just happened to me. I got it working, but I am baffled as to what happened. Can anyone suggest an explanation?
Generally, I keep a headset plugged into the USB but will occasionally unplug it for listening. This is Ubuntu Maté 18.04.
I was playing around, reading up on Linux arcana (minor, not major), playing the occasional YouTube video. When I decided to plug the headset in, the sound did not switch over as it usually does. When I opened he Sound properties, the headset (out and in) were both disabled despite repeated unplugging and replugging.
I tried suspending, but when I pressed enter to revive it, the screen was a pattern of black and white rectangles, and totally unresponsive. Terminal would not open, keyboard lighhtes did not come on.
I did the drastic step of holding down the power key and restarting. FSCK ran, found 9 inodes with the wrong dtime, fixed each of them and exited with status = 1
It booted OK, all systems working.
But what happened?
Was there anything else I could have done?
I welcome suggestions on another subject description, if that would help others…