Re: Black screen
That's wasting your expensive time, certainly. I seem to remember a story about Steve Jobs urging a programmer or an engineer to make an Apple PC boot faster, because one second saved, multiplied by the expected number of Apple users and, inevitably, the number of times you have to reboot, amounted to saving many lives.
I think there's a "familiarity breeds contempt" factor where a device which appears to boot quickly when you get it, but to take far too long a year later, may have not actually changed, but it seems a longer time when you aren't waiting with breathless excitement any more. In this case, maybe you never were.
Then again, maybe it's waiting for activity on the network port, or the dock, or something.
Waiting for our electronic overlords is an experience that we all share.
So, one possible remedy is to time exactly how long it takes to boot, and to see if that's consistent. And then you know if there's just time to brew a beverage of your choice (icon). Or, put the thing next to an old AM or FM radio, or any unshielded sound speaker. Security or not, you'll probably be able to hear what the machine is thinking.