Fanuc Spindle Amplifier Alarm 41

Fanuc 6055 digital spindle amplifiers
Fanuc 6072, 6078, 6082, 6088, 6102 amps
Fanuc 6111, 6112, 6116, 6141, 6142 amps
Fanuc 6063, 6064 serial spindle amps

The position where the one-rotation signal of the a position coder
is generated is incorrect.
The position where the one-rotation signal of the MZ sensor or BZ
sensor is generated is incorrect.
The position where the one-rotation signal of a position coder S is
generated is incorrect. 

1. If orientation based on the external one-rotation method is used
   1. The settings of parameters are incorrect.
      Check that the gear ratio data matches the specification of the machine.
   2. Slippage between the spindle and motor
      Check that there is no slippage between the spindle and motor. Orientation based on the external one-rotation method is not applicable to V-belt connection.
2. Troubleshooting in other cases
   1. The setting of a parameter is incorrect.
      Referring to "FANUC AC SPINDLE MOTOR α series Parameter Manual (B-65160E)," check the parameter for
      sensor setting.
   2. A sensor (MZ sensor or BZ sensor) is not adjusted correctly.
      Adjust the sensor according to Subsection 4.3.4 of Part I of this manual. If the signal is not observed, replace the sensor.
   3. The a position coder is faulty.
      Check the check pin PSD on the spindle check board. If the signal is not generated per rotation, replace the position coder.
   4. The shielding of the cable between the sensor and SPM is faulty.
   5. The signal cable is bundled with the servo motor power line.
      If the cable between the sensor and SPM is bundled with the servo motor power line, separate them from each other.
   6. The SPM is faulty.
      Replace the SPM or SPM control printed circuit board.