Q: My macbook air

see if these articles help

OS X: When your computer spontaneously restarts or displays "Your computer restarted because of a problem." - Apple Supp…

John Galt     Mar 31, 2012 2:53 PM 
  in response to Ras68     

  

Try an SMC reset. Justifications for doing that include:

 

...

 

Power

The computer doesn't respond to the power button when pressed.

A portable Mac doesn't appear to respond properly when you close or open the lid.

The computer sleeps or shuts down unexpectedly.