To do so, I pressed the left shift+control+option+power button; now the mac turns on, the Logo and progress bar appear, it slowly advances for a few minutes then the screen just goes black... I even left it for a while to verify if it was doing something in the background but is just off... Please help!
Eric,
thanks for your response! actually it starts, I get the logo and progress bar, after a few minutes the mac just shuts down... so in summary is Startup-White screen with logo-shut down...
Boot to the Recovery Volume (command - R on a restart or hold down the option key during a restart and select Recovery Volume). Run Disk Utility Verify/Repair and Repair Permissions until you get no errors. Then reinstall the OS.
I tried restoring macbook pro (late 2011) to factory settings without erasing files, now it won´t start up, help!
