I purchased 2 new Surface Pro 3's two months ago. One machine is perfect. The other is almost perfect. The only problem is that it charges to 83% and then stops. I then get the "Plugged-in, not charging" indicator. Over the two months, it was 100%, then 92%, then 86% and now 83%. I'm afraid that this max value will continue to fall. I tried hard restart a couple times, but no success. Any ideas of how to resolve?