I've got four Dewalt drills, one's a hammer drill and the other three are similar ones without the hammer feature (they have the three speed switch and the aux handle). Two are kind of dedicated to running tugs, but the two I use both seem to be dying.

There's a lot of sparking and ozony smell from the rear end of both. I can understand one that's been living in a slightly humid environment, but the other one which sees less use is in my shop (climate controlled).

Short of some healthy blast of air had anybody any experience with sprucing these up or are they meant to be disposable. It does look like the case halves are put together with screws.