@fcomg_e, I guess your dmesg will show similar things as @stuart_marshall.
For your case, the monitor is still working but not desktop is showing up. Under such situation, please use the usb keyboard connected to Nano to type “ctrl +alt +f1 (f1~f6)” to see if you can switch it to console mode.
And you may need to share syslog (/var/log/syslog) too. Because if this is not an issue from kernel, then probably this issue is from display manager. Checking syslog will provide more info.