Can't log in or access recovery! I have a 2011 MacBookPro running OS X Yosemite. I was browsing online when suddenly my entire screen went grey (no cursor, completely unresponsive). I restarted the laptop &amp; got the usual "Update Needed" user (I have FileVault on). As soon as it reaches halfway thru the progress bar, it reboots on its own! I tried resetting the SMC, as well as holding down Cmd + R to access recovery. In the latter case, the Apple logo appears with a progress bar underneath. As soon as it reaches halfway thru, the screen turns grey &amp; it just sits there. The same thing happens when I try to boot into safe mode.

Tried many times unsuccessfully. I have a feeling this has to do with FileVault.

Help!
Turns out my 2011 MacBook Pro is one of several units suffering from a defective GPU.
I realized this issue happens only when I'm doing something GPU-related like using iPhoto or viewing certain webpages. My Mac is now completely unusable &amp; I'm going to have to get a new one.

Here's more info on this.