Johnson Fitness H106 SJED08064IF is a treadmill control board that drives the motor controller, speed sensor interface and user‑interface electronics. Common failure points on this class of boards include burned or blown power MOSFETs in the DC‑to‑AC inverter section, failed high‑current relays controlling the motor driver, and cracked capacitors on the 12 V/24 V supply rails that can cause intermittent resets or no motor start. First‑check diagnostics: verify the board’s input voltage (ensure proper 48 V battery or AC adapter level), inspect for visible damage to MOSFETs, relays, and electrolytic caps, and read any stored error codes from the treadmill’s diagnostic port before proceeding with component replacement.[oss-gpt-20b]