My shark rotary professional would not run the brush. I checked voltage to the lower detachable section and found it was getting the signal to run the brush, so I opened up the base (there are two hidden screws under the front tiny rollers, slip a stew driver under the roller and they pop right up, push down with the side of the screwdriver shank and they snap back in) and found the there is an interrupter that stops the brush when it is stowed upright. This interrupter was stuck. So I took it out thinking I would just jumper the switch out and found that it came right apart when I unscrewed it and it popped back up, turns out it was just stuck. It looks like it has some dielectric grease inside it but it had nowhere near enough so I added some and put it back together. Problem solved! Hope this helps someone, good luck!

My shark rotary professional would not run the brush. I checked voltage to the lower detachable section and found it was getting the signal to run the brush, so I opened up the base and found the there is an interrupter that stops the brush when it is stowed upright. This interrupter was stuck. So I took it out thinking I would just jumper the switch out and found that it came right apart when I unscrewed it and it popped back up, turns out it was just stuck. It looks like it has some dielectric grease inside it but it had nowhere near enough so I added some and put it back together. Problem solved! Hope this helps someone, good luck!!