Antwoord op "Why does my MacBook Pro turn on and then off again?"I had the same problem, but with two different Macs. One was the Macbook White 2011 and the other is a Macbook Pro 2010. Macbook white turned on and turned off a few seconds later. Could charging system in verbose mode, but not in normal mode. After some tests, I concluded that the problem was in the topcase, in specific the on / off button. I Replace the topcase and the white macbook returned to work perfectly. Now, the macbook pro, the problem seems to be the same as the Macbook White, but with some differences, It turn on, started the system, but turn off after a few seconds and started the process again. If I force to turning off and try to turn on, the frontal led turn on and turn off. The same issues with the fan and HD, turn on then turn off. I open it, disconnect and reconnect de battery and try to turn on, but without success. I try start the mac and then immediately disconnect the keyboard cable to see if it was the topcase power buttom, but still turn off. I think the problem is on the logic board.