I was watching a YouTube video and all of a sudden the screen got SUPER glitchy. I turned the computer off. Turned it back on and after the Apple logo appears for a few seconds the screen turns grey and nothing happens. Fans running high. Has the common graphics issue occurred with my 15" model? I will be taking it to the Apple store tomorrow but thought I'd ask here first. ALSO: I do luckily have a 13" Macbook Pro 2011 I bought for $50 a couple weeks ago and planned to use it as a backup. So glad I kept it. I assume the 13" should run fine when I switch the hard drive and RAM? And will I need to do a PRAM reset?