Well, I was planning on taking my Macbook in for repair because it was having random shutdowns, screen flicker, and it's turning orange. But since the latest software update, the random shutdowns as well as the screen flicker are gone. It seems now that the only thing needed to be fixed is the casing. Do you think i will lose my data? I don't see why I would since they're just replacing the casing. The problem is, I don't have an external drive. Should I go out and buy one or just trust that all my data will be safe?