For what it's worth, I had almost exactly the same experience with the same 2011 MacBook as 'lowbloodsugar'. From my point of view, it was clearly starting to

For what it's worth, I had almost exactly the same experience with the same 2011 MacBook as 'lowbloodsugar'. From my point of view, it was clearly starting to fail while still in AppleCare warranty (snow on the screen when doing anything graphics intensive), but somehow it passed their 'tests'. Shortly after the warranty ended, the Nvidia card failed for good. On the bright side, it was a dual-video system, and I was able to keep it running a few years longer through complicated booting rituals that convinced it to boot with the lower power Intel graphics (although I lost the ability to recover from sleep). I'm not sure why we have such different experiences with Apple customer service. I was also in the Bay Area, but not Palo Alto. It's possible that with a more aggressive approach I could have gotten them to fix it. Instead, I accepted their verdict, and now spread the word through forums like this that their warranties are not to be trusted.