Hi, I have a Nordic track treadmill control board (MC2100ELS50-2Y), it's running the motor, but sometimes it's slowing down a bit, but then running ok again for awhile. Then when I stop the treadmill from the console, the motor starts again and stops. This happens every 30 seconds. I disconnected everything except the power to the board, I can see the red LED blinks every 30 seconds. Anyone have any idea?

 

That may be a mechanical issue, such as excessive friction. There may be an over-heating issue because of the overload.

 

No there is no overload, the motor are not connected, when I put my ear close to the control board, I can hear a high frequency sound, not sure what that is. But th red LED is turning off for a split second every 30 seconds. I don't think that is normal.

 

Does it blink at the normal rate in between the interruption off?
Do you have the motor disconnected from the belt?

 

It's not blinking, it's on constantly

 

The motor is disconnected from the control board

 

It is normal to be on Constant, until it receives a command and then it should be a slow pulse rate.
The best way to trouble shoot these boards is stand-alone on the bench, as the other processor in the Op panel can confuse things.
But you need the 20Hz PWM signal into HD2 pin 4.

 

mc2100els 50w motor rotate intermittently

 

Do you have a way of bench testing the main board ?
20Hz input signal required

 

Do you have a way of bench testing the main board ?
20Hz input signal required

actually now i dont have 1khz below frequency generator, but do you have experience about wth that problem

 

There are cheap signal generator units out there that work,
I built some small controller boards awhile ago that have the stop/start PB inputs on also.