This leads me to believe the issue lies with the GPU, but I am not sure how I could confirm this. If I boot in verbose mode and look at the output, these are the last lines before the screen turns blank: fGPUIdleIntervalMS = 0 When this happens, whatever install media it was reading from, it stops accessing, as if the system had halted. However, whenever I boot the install media, be it a flash drive, hard drive, or DVD, the installation gets about 1/3 of the way through and then goes to a blank white or grey screen. The hard drive was removed, so I put in a new one and have been trying to install OS X Yosemite. I have a late 2011 MacBook Pro (MD322LL/A) given to me by a friend.
