Aerobics Inc. J0311029‑2 is a treadmill motor controller board used in PaceMaster digital models. Common failure modes on this class of boards include burnt or failed MOSFETs/IGBTs, damaged driver ICs, and capacitor degradation causing erratic speed control or no motor response. Check the power supply rail voltages (typically 48 VDC to the motor bus) for continuity and correct voltage; inspect the board for burn marks or swollen electrolytics, then verify I/O signals between the microcontroller and motor driver ICs with an oscilloscope. If the board passes visual and electrical checks but still misbehaves, review any stored error codes via the treadmill’s diagnostic port before proceeding to component replacement.[oss-gpt-20b]