Batterie plugged in, not charging. Surface shutdown when unplugged and cannot boot unplugged.

Had my Surface Pro 1 for a years and half (Bought it as soon as it came out), loved it but I started to have this error about two weeks ago.



Basically, the icon of the batteries say : "42% available (plugged in, not charging)". Last week it was ~30% and this week it varies between 42-44%...



The power cord light is on and there's no red X on the battery icon. Everything in windows seem great except the "Not Charging".



I tried quite everything. Uninstalling drivers and shutdown with volume + or volume -. I've reset my Surface to 8, updated to 8.1U1. Even called the Surface Support and had the guy helped me for an hour, all without success...



And since my Surface Pro is now ~6 month past warranty, it'll cost me 300$ if I send the Surface for repair for a device that worth......about 300$ on eBay. And I seriously doubt the problem come from a bad handling of the Surface. This sort of problem clearly look like a conception mistake.



I'm out of patience and I just started my Master degree in mechanical engineering in aerospace and my Surface Pro 1 have become quite an irreplaceable tool. And as a student with big debt, I cannot really afford another Surface or the 300$ price for repair...



Suggestion?