Why is my sander not sanding?

If your sander is not sanding there could be a few different problems. First one being you need a new piece of sandpaper, in which case you should replace the sandpaper. Your sand paper could also be too high of a grit making the abrasive surface not rough enough to do any real damage, try gradually using lower grits until the surface begins sanding. If you go too low and scratch marks appear just work your way up to higher grits. Your device could also not be operating properly in which case I would check this devices troubleshooting page to search for causes for various problems.