Flicking it after turning the computer on turns it back off. There is a chance you just kept turning it back off on accident.
No, tried it again, nothing happens: after the intro I go to the fuse box, activate it once (only one click), go back and the screen is still dark. Is there any way to get logging/debug information?
That is very odd. I'm not sure there is any debug info you could get on your side, but if you could record it happening that would be helpful.