The Aerobics Inc. Pacemaster Pro Series 9501001 Rev. K treadmill board is the main motor‑control module that drives the lower motor and manages speed, incline, and safety interlocks on the PaceMaster Pro treadmill. Common failure modes include burnt or tripped MOSFETs in the H‑bridge, failed optocouplers or relays that disconnect the motor driver, and damaged PCB traces from vibration or overheating; these often manifest as no motor response, intermittent speed changes, or error codes such as “MOTOR FAIL.” First‑check diagnostics: verify 48 V DC supply continuity to the board, inspect for visible burn marks or cracked components, and read any diagnostic LEDs or serial fault codes via the controller’s debug port. If power and component integrity are confirmed, test the motor driver outputs with a multimeter while cycling speed settings to isolate the faulty sub‑circuit.[oss-gpt-20b]