I purchased a macbook to lug around with me while I was out and about. I use my 27in 5k to do most of my work, so I generally don't do much on my Macbook. About 4 days ago the screen went black and everything was completely unresponsive. About 5 min later it would turn back on and about 10 seconds after logging in it would do it again. 4 days later and the trackpad won't let me drag, sometimes doesn't vibrate and graphics are sometimes choppy during a fully loaded video. It does this periodically, but not all of the time. I took a video of when it did happen just to have (I don't know if that will mean anything). I have an appointment at the genius bar tomorrow. What's the best case scenario? can I ask for an exchange if it doesn't act up in front of them? Don't want to waste their time or mine. Just want a reliable machine. Thanks in advance.