To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
My macbook pro mid-2009 wouldn't boot up all of a sudden, and only displayed a flashing folder with a question mark on it. I searched with description of the problem, and a youtube video came up that explained that it was probably the hard drive cable. I ordered the cable and replaced, and my macbook pro was (and still is) fixed!!!