Reason 1: Excessive scaling on the surface of the commutator

Reason 2: The armature coil is damaged

Reason 3: Broken meshing gear

Reason 4: The rotation is not working properly - the armature shaft is stuck

Reason 5: the rotation is not working well - the carbon brush spring is too tight

Troubleshooting method: adjust or replace

Reason 6: The bearing is too loose and makes noise
Troubleshooting method: replace

Reason 7: The meshing gear cannot be meshed - the battery is insufficient
Troubleshooting method: Charging

Reason 8: The meshing gear cannot be meshed - the pull-in coil is damaged
Troubleshooting method: replace

Reason 9: The meshing gear does not mesh - the thrust spring is broken
Troubleshooting method: replace

Reason 10: The meshing gear cannot be separated - the guide cylinder and the spiral groove are stuck
Troubleshooting method: check exclusion

Reason 11: The meshing gear cannot be separated - the return spring is broken
Troubleshooting method: replace