The part you should check first when you are servicing a sparking universal motor is the a. commutator. b. armature. c. brushes. d. field windings.

The part you should check first when you are servicing a sparking universal motor is the C. brushes. It is better to start from brushes because they are most likely source of the sparking. So in order to organize a basic safety in your working place, make sure the brushes are OK.