The Aerobics Inc. 9501001 is a treadmill motor control board used in PaceMaster Pro and related models; it houses the main drive relays, power MOSFETs, and a microcontroller that manages speed, incline, and safety interlocks. Common failure modes include burnt or tripped relays, degraded electrolytic capacitors on the 120 VAC input, and firmware corruption leading to erratic motor behavior or error codes such as “E01” (motor fault). First‑check diagnostics: verify the 120 VAC supply voltage and continuity of the relay contacts; inspect the board for bulging or leaking capacitors and solder joint integrity; review any diagnostic LEDs or error code displays against the manufacturer’s reference.[oss-gpt-20b]