A) Enter Open Loop Speed mode and set treadmill speed to confirm proper line voltage to pwm board and that the green BELTSW light is lit on the relay board. Replace upper display board or relay board if necessary.
B) Inspect speed control wiring and correct wiring if necessary:
- Checking purple wire from V+ on pwm board to P3 on the relay board
- Checking orange wire from P1 on pwm board to P1 on the relay board
- Checking brown wire from P2 on pwm board to P2 on the relay board
- Confirm P3 on pmw board has no connection
C) Inspect motor control wiring, checking wires from motor to A+ and A-. Correct wiring if necessary.
D) Inspect motor brushes verifying brushes slide freely, are at least 3/8" long, are curved and have no burns or cracks. Also check the brush springs and verify that the brush copper wire is not burned or broken. Replace both motor brushes if necessary.
E) Inspect motor turns and is not seized up or has a broken shaft. Replace motor if necessary. Also verify at least 90VDC present from the black (A+) wire and white (A-) wire from the pwm board to the drive motor. If voltage is present, replace pwm/relay combo board. If no voltage present, replace drive motor.