Look for kinks or cuts in the encoder feedback cable. If the alarm only occurs when the spindle or an axis moves, it is a strong indicator of a conductor break inside the cable.
Clear the current program and type a simple command: G90 G00 X10. Y10. in MDI. If this runs fine but your production program fails, the issue is in the CAM-generated code, not the machine.
Every motor and amplifier has a rated duty cycle. FANUC motors are typically rated for continuous operation, but only within specific torque limits. fanuc alarm 7127
A physical limit switch or a stuck emergency stop button can cause the PMC to send an illegal axis enable signal. Inspect the operator panel and limit switches.
Check your FANUC Manual to ensure the position coder type and resolution settings in the parameters match your hardware. Look for kinks or cuts in the encoder feedback cable
Technician replaced the Y-axis servo motor and rewired the pulse coder. Alarm 7127 appears at power-up. Cause: He swapped the FSSB cables between the Y and Z drives. The CNC saw Z-axis feedback where it expected Y. Solution: Re-terminated FSSB cables correctly and performed a "FSSB Reset."
Go to the screen (press [SYSTEM] then right-arrow soft key). Write down: Every motor and amplifier has a rated duty cycle
Ensure all connectors on the spindle amplifier (often labeled JY2 , JY4 , or JY5 ) and at the motor are seated correctly.
Here is your checklist. Stop the program and check these four things first.