MacBook Air totally dead, won't start up
I shut down my 2014 MacBook Air yesterday morning to take it with me to a friend's house. When I tried to start it up it simply wouldn't start. Does not respond to the power button or make any sign of life. Battery is fully charged (green light on power cable and no battery problems so far). I tried holding the power down for long periods, and using various combinations of shift - ctrl keys at the same time, but nothing moves it. What to do?
MacBook Air, OS X Yosemite (10.10.3)