Hello all, new guy here. I’ve read through a lot of the forums on this controller that I have been troubleshooting and didn’t find one with similar issues as what I am experiencing. This controller is on a pro form treadmill. The controller sends a burst of voltage to the belt drive motor and quits immediately. I can repeat this by pressing stop and then start again. The led on the board blinks 4 times repeatedly after trying to start the motor. I have tested the motor and even tried a different motor and am getting the same issue. I am not seeing any physical evidence of malfunction on the board. Any advice on where to go from here? Also, after pressing start and after the board tries to run the motor, the display shows as if the treadmill is running. I’ve tried the troubleshooting steps and got to the calibration display. The PWM displays 20 or 21 when in this “faulted” state. Unsure if that means anything.

 

It should not send a "Burst" of voltage, it should ramp the DC up via the SCR.
Have you tried the motor off-load?
It is very much easier to TS these boards on the bench, but you need the 20Hz PWM generator to send the 20Hz pulses into pin 4 of HD2.















'burst

 

It should not send a "Burst" of voltage, it should ramp the DC up via the SCR.
Have you tried the motor off-load?
It is very much easier to TS these boards on the bench, but you need the 20Hz PWM generator to send the 20Hz pulses into pin 4 of HD2.










Thank you for your response. I have tested the motor offload. I am getting the same result.




'burst

 

The thing that makes TS a little more difficult on this machine is that there are two processors, one in the console, and one on the main motor board.
The bench test is far easier, check the semi conductors on the heat sink frame.