Thanks Reg, but I did all that.
I left it alone for about an hour and it's working again, although the language looks like Portuguese
Kind of tricky changing the language setting when you can't really read it... There, it's back to English.
I turned the brightness down to 40%. It was only 50% to start with; that's the default and a good setting.
I just turned it off and back on and that white-screened it again.