After 2 hours I gave up and held down the power button for 5 seconds to force poweroff. Next reboot, I get a boot chime, but still a black screen. Force power o

After 2 hours I gave up and held down the power button for 5 seconds to force poweroff. Next reboot, I get a boot chime, but still a black screen. Force power off. Cold boot again and zap PRAM, still black screen. This update has fucked my mac over, or it's one hell of a coincidental hardware fail It really pisses me off when Apple buries firmware updates into system software updates. I have no idea if this update contained a firmware update, and whether this problem I'm having now might be a failed firmware update? But I'm pissed off. If Apple wants to prevent me from installing OS updates until I have a firmware update applied, they can do that, but this total lack of disclosure what is being done, and therefore what failed, is really really fucking annoying.