

Even with a frozen system you can often still ensure data is written to inspect on the next boot. You may have a key labeled SysRq which likely needs an Alt modifier to trigger.
Alt+Shift+SysRq+s to sync data to disk. Alt+Shift+SysRq+u to unmount the disks. Alt+Shift+SysRq+b to reboot the system.
Execute them in that order.
This can help ensure the data about the mishap is written to disk so it can be inspected after the forced reboot. I also check the logs in /var/log but I suppose all of those are in journalctl too these days.








Totally switch to a terminal first like you suggested and see if you can work your way from there. My suggestion goes after yours. Always try to fix the running system first.
It’s probably wise to check man pages and other introductory documentation for most system administration tasks. Even though they’re super low-level, they are in my opinion better to send than just pulling the power plug.