Voltage is supplied through the lamp to the collector plates and to the anchor core. The lamp burning indicates a short circuit of the winding or collector plates with the mass. When checking with a megohmmeter, it should show a resistance of at least 10 kOhm. Replace the anchor that has a short circuit with the mass.
Use a special device to check whether there are short circuits between the armature winding sections or the collector plates, and whether there are breaks where the winding section leads are soldered to the collector plates.
Inspect the working surface of the manifold. If it is dirty or burnt, clean it with fine-grained sandpaper.
Drive. The starter drive must move freely on the shaft without noticeable jamming. The gear must rotate relative to the drive shaft in the direction of rotation of the anchor under the action of a torque of no more than 0.27 Nm (2.8 kgf·cm). The gear must not rotate in the opposite direction. If there are nicks on the entry part of the gear teeth, then grind them with a fine-grained emery wheel of small diameter.
If the drive parts are damaged or significantly worn, replace the drive with a new one.
Covers and supports. Check for cracks on the drive side cover. If there are any, replace the cover with a new one. Check the condition of the cover liners and shaft supports. If they are worn, replace the liners or supports and covers together with the liners.
Brush holder. Check the reliability of the brush holder fastening on the back cover. The brushes should move freely in the grooves of the brush holders. The distance from the brush output to the working edge should be at least 3.5 mm. If the brushes are worn more, they must be replaced.
Traction relay. Check the ease of movement of the relay anchor. Check with an ohmmeter whether the relay contact bolts are closed by the contact plate. If the contact bolts do not close, disassemble the relay and clean the contact bolts with fine-grained sandpaper or a flat velvet file.
Reducer. Check the condition of the gear teeth and needle bearings of the planetary gears; replace damaged gears and bearings.