Hi, I am thinking about buying a cheap Macbook Pro for my young son. I found a late 2011 13" MBP which according to the seller is in perfect condition but the trackpad needs replacement. From what I can see on ifixit changing the trackpad is quite easy and the part is not so expensive. But I am wondering: what is usually the reason for a non-working trackpad. Could this be an indicator of water damage? If so is there an easy way to see it? Any opinion and known other issues with the late 2011 13" Pro would be very helpful. Thank you.