I purchased my first Mac ever a few months ago. It was a used 2010 MBP 15. It had issues of some kind. It would randomly shut off, like in the sleep mode, but it would not come back on unless I held down the power button for a while, release it and press down again. This would happen in all kinds of activities, no pattern to it. I brought it to an authorized repair shop and they replaced the Logic board under Apple Care. It still happened. I drove to the Apple store (75 miles) they replaced the logic board again and the hard drive, Apple Care again. It worked ok for about a month, it started again. I drove back to the Apple Store again. First they said I had an after market memory and it would not be covered. Then the guy I was talking to went away and came back and told me, " heck we will just replace it." So thanks to the mercy of the Apple Store I now have a new 2011 MBP i7 15 I just had to pay $200.00 to upgrade to 8 gigs (my choice). Now I can get back to learning Mac. At 61 and not the brightest bulb, if you know what I mean . I am trying to do some video and audio recording. Anyway like I said a very happy ending. Thank you Apple and Apple Care!