Aw, that's a shame :<
Yeah I started getting the plugged in not charging message about two weeks ago. My solution that works for me is to uninstall/reinstall the battery in device manager then it works for a few days. It's fickle, but it's not really something I think about anymore. Also even if it says that, it will still charge if you uninstall the driver, turn it off(not sleeping), and plug it in, assuming you dont actually have physical damage. This has worked for some people online.
I used to get it to charge by wiggling the cord or squeezing the casing, which made me think it was physical. I think it might be a combination, it seems to stop charging if the machine is hot. and the power cord gets HOT. like right now it's painful to touch the plastic on the charging end of the cord and I'm plugged in, charging.so it might be windows detecting a dangerous temperature or something. Who knows?
Other than that it's still running great.
An artist on instagram had the same problem so she had wacom ship her a new power cord and it works for her, so in that case it was a physical problem. I suggest you get a new cord because from my experience it might be heat related on the driver side. so if you get a non faulty cord that doesnt overheat, maybe windows wont get mad.
I also am using windows 8.1 btw. They might have changed some things relevant to this problem that gets it to work for me.
I haven't experienced any dust under the screen, then again I give it a once over with a vacuum and cloth every few days to keep it clean, the only damage to the product is a small nick in the screen coating from my gf throwing something with a zipper on it, but other than that the casing and screen are like new after daily use. I've had it since mid december.
I'm not so sure I'm one of the lucky ones. The problems I have, as workable as they may be, shouldnt be there after dropping $2500 on it.