a rough schematic for this controller is on post 2 of http://forum.allaboutcircuits.com/showthread.php?t=18895
It has some resistors missing etc but is very useful.

 

My walking machine damage now does 380 days thanks anyway

 

I have a controller mc-60 I 12v LED lights and cntl spd but trig scr LED lights work I incline the engine but not the tape will change the fet was crossed S4020L may be what this wrong with this board

 

I have a proform pt 6.0 with the same mc 60 controller board. the RPS 1 resister has one cut lead looks as though done during manufacturig. treadmill has been fine for a long time and i'm the only one who's been inside. Thinking maybe depending on application whether RSP 1 is used or not. the lead definitly looks cut not broken.

Me myself am trying to figure out how much AC( dc voltage ripple) should or should not be on motor leads. With ac meter have 16vac at 1mph and up to 30vac at 7mph with 70vdc at same time. Don't know if i'm reading a pusating dc voltage that is supposed to be there or not. Now very resently an ac hum started comimng from belt drive motor. And also started triping 15 amp circuit breaker. Can't seem to find specs on the board so i don't know what i should be reading. I'm brand new to this forum thing. but if anyone have any advise would be greatly appreciated

Clean the Motor commutator for carbon deposit and while u are at it, inspect the carbon brushes too. Replace them if they are worn out.

 

I have a controller mc-60 I 12v LED lights and cntl spd but trig scr LED lights work I incline the engine but not the tape will change the fet was crossed S4020L may be what this wrong with this board

I hardly understand what you are asking.