Vigoservo AR series (e.g., AR15B120‑BA0, AR60C121‑BAO) are integrated single‑axis servo actuators that combine a high‑rigidity reduction gear, motor, brake and encoder into one compact unit with an internal amplifier/controller. Common failure points in this class include power supply over‑voltage to the actuator, loss of encoder signal or mis‑alignment causing excessive torque spikes, and thermal overload of the integrated motor or amplifier due to inadequate ventilation. Initial checks should verify that the 48 V/AC input is within spec, inspect all wiring for insulation damage or loose connections, confirm encoder feedback and brake status via the controller diagnostics, and review any error codes displayed on the built‑in panel before proceeding with deeper component testing.[oss-gpt-20b]