Hi, everyone.
I recently bought second hand treadmill and have this issue:
Belt is running well without load. Speeds up and slows down. Passing speed test (read speed identical to set speed).
When I step on belt in slows down dramatically Especially on low speed it is almost stops.
I'm not sure what to blame: motor or board. I wonder is signal from reed sensor is used for speed feedback?
I can hear light clicking noise from motor. Would it be issue?
Main board is MC2100LTS-30.

 

I would take voltage readings across motor when it slows down, also, check motor current, if you have suitable ammeter.

 

Am I right here is constant voltage on C5 and motor controlled PWM via Q2? Should reading from reed switch extend pulse duration to keep constant speed? I have digital true RMS multimeter and DC clamp meter.

 

https://www.treadmilldoctor.com/treadmill-belt-bogs-down

 

This would be too easy.

 

Just tested. Under load voltage goes up 10-20% depends on load applied and current jumps ~3 times. So, looks like board is fine?

 

Problem solved. 1 wire disattached from motor commutator. Bad manufacturing
Soldered, polished commutator. Works fine now.