I have an early 2011 MacBook Pro 15" 2.2ghz i7 quad, 8GB, 240gb SSD. OS X 10.10 > I get chime when powers on > OS gets stuck on the loading screen 1/4 of the way. Then restarts (then repeat) or the screen goes back and then turns on to go to a white screen without the apple logo. * reset PRAM * reset smc * tried to boot from recovery + multiple external drives including dvd OS installs, does the same thing! * ran extended diagnostics from DVDs and no hardware issues. * all the drives boot fine on an identical machine. This happened few days ago but it randomly worked out of the blue so I ran disk check just to verify and no issues. What the heck is going on? I'm pulling my hair out over this. Would love some wisdom. Please help.