: The spindle amplifier module might not be receiving the correct signal from the CNC control to switch the contactors.
: The mechanical or electrical failure of the spindle speed switching contactors themselves. fanuc 7115 alarm
Once you resolve alarm 7115, take these steps to ensure it never returns. : The spindle amplifier module might not be
: Test the 24VDC supply while the machine is attempting a tool change or gear shift. If the voltage dips significantly, replace the power supply module . the switching circuit cannot operate.
: This is the most frequent culprit. If the 24VDC power supply (often manufactured by brands like Izumi) that powers the relay and contactor coils fails, the switching circuit cannot operate.