Fanuc Spindle 750 Alarm and Servo SV5

Fanuc Spindle 750 Alarm and Servo SV5136 Alarm

If the above alarms appear when the machine is powered on, it is generally due to the absence of LED display on the power module, spindle amplifier, and servo amplifier. Please check if there is a 200V input at the CX1A connector of the power module (PSM). If the 200V input is normal, replace the control board of the power module (PSM).

Common Fault Diagnosis for FANUC Without Alarm Information:

1750 Alarm:
This occurs when, in a serial spindle system, the spindle servo module does not reach the normal startup state when powered on. In this case, the diagnostic function with diagnostic number 409 can be used to display the alarm status for identifying the specific fault cause.

2SV5136 Alarm:
If the SV5136 alarm appears:
   1.   Check if the control power (24V) for each servo amplifier (SVM) is normal and whether the LED is displaying. If the LED is not displayed and the 24V power input is normal, it can be determined that the servo amplifier is faulty.
   2.   If the LED is displaying, check the FSSB fiber optic cable connectors COP10A and COP10B at the bottom. If the light does not show from one of the connectors, it can be determined that the amplifier is faulty.
   3.   Check the FSSB fiber optic cable connecting the servo amplifier and the system axis card for faults. (To check, use a flashlight to shine on one end of the cable. If both optical ports on the other end emit light, the cable is fine; if not, it is faulty.)
   4.   Confirm whether the parameters have been changed, and restore the machine’s original parameters.

SV5136 (FSSB: Insufficient Amplifier Quantity) 2SV5136 Troubleshooting Method:

Cause of Alarm:
The number of servo amplifiers identified on the FSSB is less than the number of control axes. FSSB: Insufficient Amplifier Quantity.

Troubleshooting Steps:
   1.   In the FSSB setting screen, display the amplifier settings page under the alarm condition. This will show only the servo amplifiers recognized by the FSSB.
   2.   The fiber optic cable or servo amplifier point may have a bad connection between the last recognized amplifier and the following amplifier. It could also be that one of the amplifiers connected at either end of the fiber optic cable is faulty. Additionally, check the power supply for the amplifier.
   3.   Abnormal power supply to the servo amplifier: If there is an issue with the power supply within the servo amplifier, this alarm will also occur. In addition to the drop in amplifier control power, for example, if the +5V from the pulse encoder cable is grounded, it will cause a power supply abnormality.
   4.   The axis control card may be faulty: This could be due to a faulty axis control card installed on the CNC side.