A frequent culprit is a failed or weak 24VDC power supply (often Izumi brand in Mori Seiki cabinets), which prevents the relays and contactors from activating. Interlock or Panel Issues: It often appears alongside an EX0099 Panel Alarm
FANUC 31i-A5 on a 5-axis mill. Symptom: Intermittent 7115 alarm only when the operator opened the safety door. Diagnosis: The I/O Link daisy-chained through a safety relay. The last I/O unit (at the pendant) had a loose terminator plug. Vibration from the door opening caused a momentary open circuit. Solution: Reseated the I/O Link terminator and tightened the screws. Replaced the low-quality terminator with a genuine FANUC part (A03B-0807-K001). fanuc 7115 alarm
: A faulty resolver or damaged cables between the spindle amplifier and the motor can lead to switching faults. Parameter/Switching Logic A frequent culprit is a failed or weak