2013 MacBook Pro crashed, won’t restart I was using Firefox when my MacBook Pro crashed.  I was not initially concerned, as it does this about once a month.  However, it no longer starts.  It had 80% battery when it crashed, and plugging it in does not help.  Before I take it to the shop or take it apart, I hope someone here can offer a solution.
It is a 2013 MacBook Pro running the latest version of Yosemite.

Edit:  The computer restarts after several hours, but crashes again later.  I sought professional advice and was informed that the logic board needed to be replaced, because the not-restarting bit is apparently symptomatic of an overheated logic board.  But the problem resumed two days after a new logic board was installed.
Have you ever tried to reset NVRAM or PRAM (older Mac)? With Mac turned off, power on the Mac, then press and hold CMD (⌘) + Option (⌥) + P + R until restart itself, this should take a couple of seconds. This could be find at Apple Support, Hope it helps