Chosen Solution
My monitor is a ViewSonic 2370S. Is it the monitor or my Mac going bad?
Well you have a 50-50 problem! As we don’t have a way to isolate out which without changing out either the display or plugging in anther system into the same connection your mac Mini uses (same cable and adapter) The other approach is swapping out the display cable and if you have a dongle it as well.
