XPS 9500 Display and Battery Problem

Just started yesterday.

This is somewhat confusing…

When plugged-in, the display goes dim as though it is in maximum power saving mode. Sort of the opposite of how this should and used to work! Whether it is plugged in or not, the display brightness cannot be increased or decreased within the Display Settings (0-100) or Power Modes in the right task tray. When un-plugged, it gets a bit brighter, but it is still dim. I have not spent much time fighting with this so I thought I would cheat a bit and see if any of you have tackled this issue yet.

Incidentally, I did notice the AC adapter gets extremely hot to the touch. I mean it felt as though it was going to melt. I do not care to know the specifications, but I do not believe this to be a normal or well-designed characteristic. Thanks!