MC 2100 Full speed then shutdown

Thread Starter

Cooped_Up

Joined Aug 31, 2019
8
Hello, I have a treadmill speed controller I want to use on my lathe... I have read just about every forum post about treadmill stuff to try and figure this out. It went full speed and then shut off and the motor looked like it was on the verge of flames. anyways, I have replaced the FET which was blown and I checked the diode and it was still good. The Indicator LED is solid all the time I can post pics if that helps, but I know max has a lot of experience with these types of boards... One more note, when I put it on the lowest speed I am getting around 110VDC on the output granted I have no motor hooked up IDK if that is right. I also have an mc-60 but we can go over that once I figure out this one. I am not an expert but I do know electronics well enough to do just about anything
 

MaxHeadRoom

Joined Jul 18, 2013
20,038
If the board is getting the right command on the 8 pin input socket on the board, the LED should be flashing at a regular rate about twice a second.
What you say FET, is the this the main Mosfet on the H.S.?
Max.
 

Thread Starter

Cooped_Up

Joined Aug 31, 2019
8
If the board is getting the right command on the 8 pin input socket on the board, the LED should be flashing at a regular rate about twice a second.
What you say FET, is the this the main Mosfet on the H.S.?
Max.
Yes it's the main mosfet that I replaced, the irfp250 or whatever the numbers are I don't remember of the top of my head. The led doesn't flash it is constantly on
 

MaxHeadRoom

Joined Jul 18, 2013
20,038
LED on steady is usually the standby mode and I would think fed from the Microprocessor, the input signal comes in through an opto and goes to the Micro input.
Generally steady LED means no command signal received.
Max.
 

Thread Starter

Cooped_Up

Joined Aug 31, 2019
8
LED on steady is usually the standby mode and I would think fed from the Microprocessor, the input signal comes in through an opto and goes to the Micro input.
Generally steady LED means no command signal received.
Max.
The motor still is turned on and off by the control board... just not the speed. so you think I should check the optos then?
 

MaxHeadRoom

Joined Jul 18, 2013
20,038
If you have a 'scope that would be useful to check the PWM signal input.
If you do, take care on the 'scope common lead, the low voltage ground is isolated however.
I made up a custom PWM for the MC2100, just working now on version 2 that will have reverse and digital RPM display.
Max..
 

Thread Starter

Cooped_Up

Joined Aug 31, 2019
8
If you have a 'scope that would be useful to check the PWM signal input.
If you do, take care on the 'scope common lead, the low voltage ground is isolated however.
I made up a custom PWM for the MC2100, just working now on version 2 that will have reverse and digital RPM display.
Max..
I have two scopes, I think i can check that out, so you are referring to the input and output of the optos or just the microprocessor or whatever that chip is? okay, so the first picture which is the one with the easy to see wave is on the optos on the opposing side of header 2. the second picture is the header 2 pin 4 or the blue one this pwm signal is only around .1volts so idk what it is supposed to be.
 

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Thread Starter

Cooped_Up

Joined Aug 31, 2019
8
The PWM for motor speed control input is 20Hz.
It is the opto connected to pin 4 blue conductor.
Max.
yea i did what you said to be careful of doing and popped a breaker blew the 5v regulator on the board. i possibly fried the controller im not sure yet, i need to replace the regulator. but yes the opto is connected to pin 4
 
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