Reminds me of my computer repair days.
This happened at least once a month.
Customer: My computer wont work.
Me: Ok, whats the problem?
Customer: Its just a black screen.
Me:... did you try turning it on?
Customer: Yea, i hit the button several times but it doesn't do anything.
Me: Is it plugged in?
Customer:Uh........, its working now. *hangs up*