greetings I need some help. Last night i purchased a nicely used Macbook Pro 9,2. Its got the dual i7, 8gb Ram(which geeksquad put in ew) and the 1tb drive. I took the guy to the Apple store to make sure everything was alright. Apple said everything was a pass, aside from the RAM's manufacturer wasnt noted. So i took it home, put my SSD in it, installed EL capitan and everything went smoothly. Today i booted it up, and upon watching a youtube video the top of the screen began to artifact then disappeared. I rebooted the machine, did a PRAM reset and booted back into oSX. within seconds the bottom of the screen began to artifact too! ANy suggestions are helpful as i dropped a lot on this used machine and within a day its doing this. Not a good start!