Logic board failure
My MacBook Pro wouldn't turn on after using it less than six months from new purchase (Dec. 2014) and I took it to simply mac who said the power switch or something was loose and they fixed it. Then after another month I took it to an Apple Store for the same problem. They got it started up again. This time it worked for a month. Then boom the same thing. So now I have it back and they replaced the logic board and it seems to be working. Did anything ever come of the class action suit about the faulty boards ?