Hoover dust manager stopped working?

My Dust manager has stopped working. The fuse is fine and power is getting to the circuitboard. It smelled of burn first then cut out a few times then finally stopped. I have removed all fluff etc from hoover and filters but still does niot work. I am conmcerned that the motor is burned out but I can see no sign of this. Only other thought is the circuit board has blown but cannot see ant damage. Can you offer any advice?