Alt+F7 to go back to the graphical session. Like I wrote in
https://trisquel.info/forum/need-uninstall-trisquel#comment-104366
Right after firing 'top', you get a list of processes (let us say "programs"
to simplify) in decreasing order of %CPU, i.e., of how much processor power
each of them is currently draining. The names of the programs are in the
rightmost column. If a program is malfunctioning (and causing your display
issues), it will probably be at the top of the list, taking much resource.
Not only computing resources (%CPU) but also memory (%MEM). The 'q' key quits
'top'.
Again, "GNOME System Log" is just a log viewer. It only allows to read the
logs in /var/logs (that you are already looking at), to search in them, etc.
You can attach the logs to your posts here: we may find interesting things
for you. I was suggesting to copy the logs right after the screen gets
scrambled so that we know interesting things (if any) would be written at the
end of the logs.
