How to test armatures or motor armatures of polishers, drills, blenders, vacuum cleaners, etc. universal brush or carbon motor, first is the visual inspection to determine visible damage such as the worn shaft or the commutator or commutator eroded or with thin leaks, it continues with the ground test with an ohmmeter, then the very important continuity test of the bars and finally the test of shorted or crossed coils with the growler