debugging - I have a hardware detection problem, what logs do I need to look into? - Ask Ubuntu:

Then, causing the problem to happen, and listing the system’s logs in reverse order of modification time:

ls -lrt /var/log, tail -n 25 on recently modified log files (for reasonable values of 25), and dmesg.

Read, wonder, think, guess, test, repeat as needed

Causing the problem and then looking at the recently modified logs is common sense but brilliant.

And saving ls -lrt as “list by modification time”.

-t is “sort by modification time” and is easy to remember.