Rotor check
1. Check the resistance of the rotor windings and compare the obtained value with the specification (see section «Service data and specification» at the end of the chapter). If the value obtained is not correct, replace the rotor with a new one.
2. Check for breakdowns in the rotor winding. If breakdowns are found, replace the rotor with a new one.
3. Check the wear of the slip ring and compare it with the limit value (see section «Service data and specification» at the end of the chapter). If the value obtained is not correct, replace the rotor with a new one.
Checking the brushes
1. Check the smooth movement of the brushes. If the brushes are jammed, check and clean the brush holder.
2. Check brush wear. If the length of the brushes is less than the maximum allowable (see section «Service data and specification» at the end of the chapter), replace the brushes with new ones.
Stator check
1. Check the continuity of the stator winding circuit. If the circuit is open, replace the stator with a new one.
2. Check the stator winding for breakdown to ground. If breakdown is detected, replace the stator with a new one.