T's screens went dark after H uploaded a new game. He couldn't even reboot because nothing happened.
He told us both to go away, so we fled to leave him him in peace to work out what to do. All computer problems get solved sooner or later in this house. We stayed out of range for an hour maybe.
Calm is restored, T's screens are all back in action and life goes on. They might be built on logic, but they seem very temperamental to me.
Just now I solved a simpler problem, H had an ID and password for his email which were far too complicated to ever spell correctly. So I have re-registered him with a deadly simple ID and password so at least he has a functioning email account.