A scanner with a simplified document feeding path is provided for scanning a document. The composite squirrel cage rotor includes a rotating shaft, an inner core, a polymer resin part that fills the cavity of the squirrel cage conductor and contains powder of high magnetic permeability. If one is detected, this performance parameter is then evaluated under at least two different performance conditions to generate a second set of current engine data that is compared to a second set of prior engine data to determine if there is an abnormality.