Help with treadmill.

[Jbomb]

Hi guys, this is the last throw of the dice before I cut my losses and scrap it, I really want to get it going though as it has hardly done any miles.

I have a Nordictrack t9si that started malfunctioning. Long story short I have recently replaced the control board and then the motor. It was initially losing speed after a few minutes of use then stopping but now, since moving it inside the house from the garage as I suspected damp was an issue, it blows the 13A fuse in the plug as soon as the motor is engaged. It is also doing the following:

If I disconnect the (brand new) motor the single LED goes from continuously on when powered up (as it should) to continuously off when speed is turned on (it should blink). The LED will come on again after I either disconnect and reconnect the power cord or wait approx 60 seconds. The incline motor works fine even when LED is off. If I press start or speed up with the motor connected the fuse blows immediately.

I have used a multi meter to see what the PCB is outputting and it seems to send a large amount of power out that gradually dwindles down to zero even if I increase the speed on the control panel.

I have a voltage diagram that I could show if anyone thinks they may be able to help. I am (relatively) inexperienced at electronics but usually am able to muddle through using online advice/resources but this one has me stumped.

I would appreciate any advice or help greatly.

Thank you.

 

[ClydeCrashKop]

With the motor installed, can you manually turn the pulley, belt, gears, etc.?
Does everything turn freely?

 

[Jbomb]

Hi, Thanks for the reply. Yes everything moves freely. Even with the drive belt removed it trips out.

 

[dr pepper]

On a sideline, if you decide to scrap it put the motor on ebay, they are popular in wind turbine generators.

 

[cowboybob]

...I have a voltage diagram that I could show if anyone thinks they may be able to help. ...I would appreciate any advice or help greatly. ...

First of all, Welcome, Jbomb!

Don't know for sure what a "voltage diagram" may show us, but it's a starting point so, yes, please post the diagram. A full schematic would be much better but I have a sneaking suspicion that no such beast exists.

On the surface it sounds like the circuit for the tread motor has a shorted final driver component.

 

[Jbomb]

First of all, Welcome, Jbomb!

Don't know for sure what a "voltage diagram" may show us, but it's a starting point so, yes, please post the diagram. A full schematic would be much better but I have a sneaking suspicion that no such beast exists.

On the surface it sounds like the circuit for the tread motor has a shorted final driver component.

Hi, thanks for the reply. The said diagram and also the offending control board (the old one) the new one is fitted to the treadmill but with the exact same symptoms. I'm guessing as I have not been able to find a problem with the wiring that the faulty motor has kaputted both boards? Any help is greatly appreciated as I have pulled almost all of my hair out over this.

 

[cowboybob]

The MC2100 (various revisions) motor controller is used is an variety of tread mills and is a favorite as a controller for all sorts of alternate uses: lathe motors, fans, you name it.

Here's a "reverse engineered" schematic I found:

**broken link removed**

There's an LED that should blink when the board is powered: does it?

 

[Jbomb]

The MC2100 (various revisions) motor controller is used is an variety of tread mills and is a favorite as a controller for all sorts of alternate uses: lathe motors, fans, you name it.

Here's a "reverse engineered" schematic I found:

**broken link removed**

There's an LED that should blink when the board is powered: does it?

Hi, thanks for the reply and info. I am starting to feel slightly less nihilistic about this whole sorry episode. To answer your question: There is an LED that comes on and stays on when powered up. It was my understanding that it should then blink when the motor is engaged (it says this on the rear of the voltage diagram). However, it goes out and remains off when the motor is disconnected and I press 'start'. If the motor is connected it seems to send a big surge to the motor and the fuse in the plug blows.

 

[ClydeCrashKop]

If the motor is connected it seems to send a big surge to the motor and the fuse in the plug blows.

I had an air conditioner that had a box on the plug with a circuit breaker reset button on it. Eventually it would pop the breaker every time I turned it on. I opened the plug box and found a circuit board with a burnt trace. I cut the cord and put a regular plug on it. It worked fine for years. It annoyed me that they had put that unnecessary BS on there. Just one more thing to go wrong. You wouldn't call a repair man to fix a window unit A/C. I wondered how many people threw away a good A/C because that plug burnt up?
I say put a normal plug on it and try it. If it is really shorted, it will blow the circuit breaker.

 

[cowboybob]

Does your PCB have this fuse? (there is no fuse shown anywhere on the schematic. Not too surprising since it's a reverse-engineered job ["REV B", I think] and this is a "REV D" board).

If so, what is its condition?

 

[Jbomb]

Does your PCB have this fuse? (there is no fuse shown anywhere on the schematic. Not too surprising since it's a reverse-engineered job ["REV B", I think] and this is a "REV D" board).View attachment 84441

If so, what is its condition?

Yes, it has that fuse and it appears to be in perfect condition. It is the 13A fuse in the plug of the kettle lead (tried 2 different leads) that keeps blowing.

 

[cowboybob]

OK.

Sounds like either the motor or its driver.

Any chance you could replace the tread motor with, say, a 10 ohm, 10 watt resistor? Only for as long as a very brief test.

Be curious to see if that load blows the fuse.

 

[Jbomb]

OK.

Sounds like either the motor or its driver.

Any chance you could replace the tread motor with, say, a 10 ohm, 10 watt resistor? Only for as long as a very brief test.

Be curious to see if that load blows the fuse.

Hi Cowboy, I appreciate you taking the time like this. I could replace the motor with a 10 ohm, 10 watt resistor but I don't have one so I'll have to get one and try that. In the meantime is there no other way I could test the output of the controller? I have hooked a multimeter up to it and it seems to behave in a strange way. Also I have hooked up a brand new motor (and also I tested the older motor with an 18V drill battery) both blow the fuse as soon as they are engaged. Is there anyway I could test the driver in the meantime as I, instinctively, suspect it is that?

 

[cowboybob]

...I have hooked a multimeter up to it and it seems to behave in a strange way. ...

The motor controller is a PWM (Pulse Width Modulation, see below) device. What that means is that it produces (as directed by the console) a pulsed, variable duty cycle signal to drive the motor, not a steady DC voltage that rises, slowly, from 0 volts up to the max and then back down. Thus your meter, without a steady input, displays nonsense.

This process closely controls the total current being applied to a device (a motor, or load, in this case) while maintaining a constant voltage level for each pulse.

... and also I tested the older motor with an 18V drill battery) both blow the fuse as soon as they are engaged. ...

When you attach a battery (or any constant voltage and current source), the full power of the source is applied to the load. Essentially, the load looks likes a dead short to the source and, as a result, the safety (fuse) blows, as designed.

... Also I have hooked up a brand new motor ...

So, your assessment of the problem (bad controller component) is probably correct. My suggestion of a temporary resistive load won't help. Unfortunely, it is equally possible that the console (speed selector) controller has failed. If, instead of a pulsed signal, it is sending a steady ON signal to the MC2100, this too would cause the fuse to blow.

The problem(s) are of a sort that a multimeter will not be sufficient for trouble shooting the system without component removal (not a good idea, under the circumstances). If you have access to an oscilloscope and know how to use one, you could observe the various inputs and outputs of the console and controller. If not, I am unsure as to what I could suggest.

One last thought: does your DVM have a "frequency" selection?

https://en.wikipedia.org/wiki/Pulse-width_modulation

 

[Jbomb]

The motor controller is a PWM (Pulse Width Modulation, see below) device. What that means is that it produces (as directed by the console) a pulsed, variable duty cycle signal to drive the motor, not a steady DC voltage that rises, slowly, from 0 volts up to the max and then back down. Thus your meter, without a steady input, displays nonsense.

This process closely controls the total current being applied to a device (a motor, or load, in this case) while maintaining a constant voltage level for each pulse.



When you attach a battery (or any constant voltage and current source), the full power of the source is applied to the load. Essentially, the load looks likes a dead short to the source and, as a result, the safety (fuse) blows, as designed.



So, your assessment of the problem (bad controller component) is probably correct. My suggestion of a temporary resistive load won't help. Unfortunely, it is equally possible that the console (speed selector) controller has failed. If, instead of a pulsed signal, it is sending a steady ON signal to the MC2100, this too would cause the fuse to blow.

The problem(s) are of a sort that a multimeter will not be sufficient for trouble shooting the system without component removal (not a good idea, under the circumstances). If you have access to an oscilloscope and know how to use one, you could observe the various inputs and outputs of the console and controller. If not, I am unsure as to what I could suggest.

One last thought: does your DVM have a "frequency" selection?

https://en.wikipedia.org/wiki/Pulse-width_modulation

That's great Cowboybob, thanks for taking the time to answer my points. I'm starting to think I may have overstated my experience level somewhat as I am a little lost. Is there a way to test the signal coming from the console? (I assume you mean the control panel, unless I am wrong about that) Also, when you say you are unsure what to suggest, does that mean I am heading down a dead end with this treadmill. I foolishly thought I had diagnosed the problem and sunk quite a bit of money into the new control board and motor so if the is ANY chance at all it can be saved I'd be ecstatic.

 

[cowboybob]

I can only suggest you find someone who has, and knows how to use, an oscilloscope. Trouple shooting this puppy will take some skill and patience (as will, conceivably, the repair).

Depending on your inclination, (and ignoring your expenditures to date) they do sell quite cheap (relatively speaking) so called DSOs (Digital Storage Scopes):

**broken link removed**

The diagnostic/repair learning curve might seem daunting and no one would fault you for giving up.

Around my neck of woods we refer to this dilemna as the "Alligator Syndrome": That which is impeding our desire to empty the swamp...

But, then, you might find yourself with a new interest/hobby (electronics) !!

Where are you located? Might be worth looking into a local Amatuer Radio (ham) group for help.

 

[Pat Bernstein]

Cowboybob, perhaps you can help me with a problem on asimilar controller. I have the MC2100ELS (no revision marked) and can't seem to find a diagram for it. The capacitor MOV1 has gone, as has the diode/thermistor? GT1. Am happy to replace both if I could identify them. All help greatly appreciated.

 

[cowboybob]

Cowboybob, perhaps you can help me with a problem on asimilar controller. I have the MC2100ELS (no revision marked) and can't seem to find a diagram for it. The capacitor MOV1 has gone, as has the diode/thermistor? GT1. Am happy to replace both if I could identify them. All help greatly appreciated.

Here's a source for one version of the controller board (no idea which): https://forum.allaboutcircuits.com/threads/mc2100-treadmill-motor-control-circuit.100678/

Note the MOV at the power input section (in the top left corner). Image is poorly focused but it can be enlarged somewhat and is still (barely) legible.

As for the physical location of the MOV (looks like a fairly large ceramic capacitor), it should be very close to and across the AC input leads/traces of the board.

 

[Pat Bernstein]

Many thanks for the help. I can't seem to identify the GT1 but looking at the forum in the link can probably get more from there. Thanka again.

 

[2PAC Mafia]

Hi all,

Happy New Year!!! I know these boards from Icon very well, I´ve repaired a lot of them (MC2100E, MC2100ELS). Usually the motor is the main problem (leakage problems and excess of current demand) and it damage the controller. Sometimes some components are damaged and sometimes even the microcontroller is damaged but I also have the option to replace it by a compatible programmed one.

If the LED is not blinking when you go to START from console is because the processor detects a shortcircuit and protects it self. The PWM signal from console is optoisolated from the controller. I would say 100% the old motor damaged the old and the new controllers...

I also sell compatible motors from another brand to replace original Icon motors.