So I just bought an early 2011 13" Macbook Pro (a new-to-me kind of thing) from my brother-in-law. I tried to play a DVD and it takes the DVD, but then there is some buzzing/grinding (not the best word, but it's all I got) and then it spits the DVD back out without anything happening. It seems like it cannot spin the disc. I tried seveal DVDs and it happened to them all. I put Mavericks on the machine. My BIL put in 8 GB RAM and a 1 TB hard drive before I bought it. Thoughts?