Why is my iPod Shuffle an "Unknown Device"?
My suspicion is that your charger was not the standard AC charger, and the voltage some how blew part of the port hardware, but not all of it. Are you near an Apple Store or a Reseller? They can probably try to boot it, and if it won't be recognized, they may give you a recycling discount on a new shuffle. It's probably not cost conscious to repair when a new one is $49.