Had the same problem, it finally smoked for a couple of bows then quit. Home Depot would not replace it because I didn't have the original receipt and hadn't registered it, was SOL. I bought another one and it was a piece junk, no where near as good as the one replaced. Took it back twice and finally got one one that was passable..for awhile. I ended up swaping out/using most of the parts from the old unit to get of running smoothly. It still works in a pinch.
Like Roy, I got a Grizzly edge sander and never looked back.