I just recieved a new Macbook two days ago. It was working just fine, until last night. I was playing around with iMovie. I took a video that was in .mp4 format, and I was editing it. When I went to play fullscreen, it worked fine. So I went to the video speed, and I tried to type in 150%. Then I tried to play it in fullscreen, and then the screen went white. I could still tab through programs, and when I pressed the on/off button, it gave me options to turn off or restart or whatever. I pressed turn off, and it just stayed there. So I held down the on/off button. It managed to come back on, but it just had a light-blue screen with the Apple icon, and a loading page. It just stayed there and did nothing. I turned it on and off a few more times after that, and then I finally managed to get it to come on after letting it sit for a while. After all of that, when I finally managed to turn it back on, it wouldn't connect to my internet. I'm about 80% sure there's nothing wrong with my modem or router. I'm new to Mac computers (this is my first one ever), and I just want to know - what caused this? How can I fix this? Do I need to send it in? Also, I have Apple support. Thanks.