12-13-2020, 08:43 PM
Ooooh. Just remembered something from last night. After the apparent software update, my Mac showed me two big, alternating, icons that meant nothing to me. One I finally decided was the underside of a mouse, with an arrow pointing to the power slide switch. The other was a flat rectangle with some sort of green slide switch on the left, arrow pointing to that, and a low rectangle like a CD slot on the right. I still have no idea what that represents. Some Googling said this happens when there's a problem with a Magic Mouse, but I don't have one of those. I swapped out keyboard and mouse both, but still can't get past the white screen. It's instantaneous as soon as I press power and hear the chime.