MC-2000H Motor Controller Repair

Thread Starter

BforBENDETTA

Joined Jun 19, 2020
5
I've been working on a HealthRider R60 (Model HCTL07120) treadmill that had been plugged into an improperly-wired outlet and, consequently, got a brief dose of 277VAC. The main fuse on the power board blew, obviously, so I replaced it. Once it was replaced, all of the controls on the treadmill started getting power, but if I tried to start the treadmill, it would only run for about half a second and then stop. I would then have to press STOP in order to try to start it again, but I get the same result.

Based on the activity of the LEDs on the power and motor control boards, I'm fairly confident that the remaining issue is on the motor controller board (Model MC-2000H).

I have no formal training in electronics repair, although I do have a great deal of experience with soldering, so the effective limit of my repair ability is visual inspection and replacing clearly damaged parts.

Upon inspecting the motor control board, I found that the MOV that's located immediately after the incoming AC voltage had violently failed (half of it ended up three inches away). I painstakingly identified, researched, sourced, and ordered an equivalent replacement MOV and soldered it onto the board in place of the failed MOV.

I naively expected the treadmill to fire right up and function normally once I powered it on, but it now behaves precisely as it did before I replaced the MOV.

As I said, I lack the formal training and knowledge to know how to proceed or troubleshoot the motor controller from here, so this is mostly a shot in the dark to see if anyone might be able/willing to at least point me in the right direction.

Please excuse my ignorance and presumptuousness in even asking for help here. I've always thought that it was rude when people online just stumble into a forum of experts and ask for help with something that should be elementary to anyone with even a passing familiarity with the forum's subject, but I'm on the hook to fix this treadmill and can't afford to replace the motor controller.

Any assistance would be GREATLY appreciated.
 

MaxHeadRoom

Joined Jul 18, 2013
28,698
I am more familiar with the MC2100 series, but there may be similarities.
Could you post a pic of the board?
It may have the same LED codes as the MC2100, what rate does the LED light or flash at?
MOV's generally commit suicide in the act of protection, if the over voltage persisted, it probably took something else out.
Looking at previous threads here, the MC2000 was a SCR version, unlike its later counterpart, the MC2100, which was PWM
Max.
 

Thread Starter

BforBENDETTA

Joined Jun 19, 2020
5
Thank you so much for the reply. From searching the forums, I had definitely gathered that the upgraded MC-2100 design is quite a bit more prevalent than the MC-2000 I'm dealing with.

I am on my way to where the treadmill is located and will take and upload some photos of the board, as well as the voltage diagram that was miraculously taped to the inside of the motor hood.

Thanks, again!
 

MaxHeadRoom

Joined Jul 18, 2013
28,698
It would seem that there are two versions/makes out there that use MC2000, one appears to be SCR the other Mosfet PWM.
A photo may show which you have.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
28,698
It appears to be the SCR bridge version by the look of the four components on the H.S. labeled D15 Q3 etc.
Never worked on one of those unfortunately! :(
Max.
 

Thread Starter

BforBENDETTA

Joined Jun 19, 2020
5
For what it's worth, here's what I observed about the behavior of the LEDs on the motor controller:

When power is applied to the treadmill, the "15V" LED is lit solid. Once I press START, the "SPD SIG" LED begins flashing and the "GATE" and "HV BUSS" LEDs light for as long as the motor runs, which is only about half a second. Once the belt has stopped, the "GATE" and "HV BUSS" LEDs go out, but the "SPD SIG" LED continues flashing indefinitely until I press the STOP button. It is at that point that I can press the START button again to begin the same doomed cycle over.

I also observed that if I manually move the belt forward, both the "GATE" and "HV BUSS" LEDs will light in sync with the speed of the belt, but nothing ever seems to change the motor's ability to continue turning the rollers and keep the belt in motion.

I doubt that any of these details will lead to any kind of eureka moment, but I wanted to put everything I had on the table before giving up. I wish I knew enough to know what components to test in order to find the broken link in the chain.
 

Thread Starter

BforBENDETTA

Joined Jun 19, 2020
5
Oh, also, for what it's worth, I noticed in the voltage diagram that the motor controller is referred to as, "MC-2000 PWM Motor Controller." Is that because this is sort of a hybrid controller as the manufacturer transitioned from SCR to PWM?

MC-2000 PWM Motor Controller from Voltage Diagram.png
 

MaxHeadRoom

Joined Jul 18, 2013
28,698
It could be that the control signal is PWM, the later MC2100 versions had both a PWM command signal and a PWM power signal to the motor.
Although oddly the HWL label is the same as the MC-60 for the potentiometer terminals to control speed.
Have you tried testing as a stand alone unit with a 5k linear pot into the H-W-L terminals and see if it runs on the bench with the power and motor leads connected.
All the other boards run this way.
What are the labels on Q3 Q2
Max.
 

gaxxter

Joined Dec 22, 2017
8
Hi, i also have an issue with this mc2000 set up, the fault:- treadmill runs flawlessly, however this is a random fault which occurs every several days and what happens is that you will come to it, power up console powers up beeps ok etc, then select a workout e.g. P4 get ready press start and the belt does not drive the console/software goes through its routine and the incline motor works as expected but no drive..........so removed cover and watched leds on control board, the error relates to the sig led which if on from first power up will cause this issue previous, so....when fault present test!, blue wire from console is NOT requesting motor drive...white wire in middle of 5 volts pwm wires is NOT requesting motor drive, when said three wires disconnected and left and reconnected several times SIGNAL light goes out and then you can use the treadmil as normal

Further investigation:
I put a scope on white wire, and selected varying speeds and appears mine is running with a 20 HZ 5v PWM signal, flat out is @ 80% duty and 4.6 km is about 15%, its working correctly as it should(When it works), i have inspected the pcb and no signs of component damage or shorts, 15v 5v all within spec etc, there is a transistor on the baord that handles this pulse in is also linked to the micro, my next step is to wait for the fault to occur again and then scope the white wire to see exactly what the rogue voltage is! Has anyone here had this fault ? i can see how the 2100 board evolved from this, two pcbs??? two seperate dc supplies for each board are they really isolated hmmm
 

gaxxter

Joined Dec 22, 2017
8
Hi, it was todo with the gnd ref and the original design and a failing discrete(even though it tested ok on normal lcr meters, i faulted it live and instigated the condition), i had to upgrade a couple of components to block this transient at switch on which would drive npn transistor(speed signal), and lock the MCU, i could get it do the glitch switching mains on/off several times about 3 secs apart, and then it would lock etc, now it does not lock at all. Strange fault as it was nowhere near to where i started first(logical assumption), the only common connection was the MCU!!!! It would of been a lot easier with a schematic even though the board is nearly 20 years old,
 

Mrhines98

Joined Oct 7, 2020
1
Hi, it was todo with the gnd ref and the original design and a failing discrete(even though it tested ok on normal lcr meters, i faulted it live and instigated the condition), i had to upgrade a couple of components to block this transient at switch on which would drive npn transistor(speed signal), and lock the MCU, i could get it do the glitch switching mains on/off several times about 3 secs apart, and then it would lock etc, now it does not lock at all. Strange fault as it was nowhere near to where i started first(logical assumption), the only common connection was the MCU!!!! It would of been a lot easier with a schematic even though the board is nearly 20 years old,
Sir, I have the exact problem you have, what components did you replace? I did replace the resistors and the coiled 7v resistor was running very hot so I did replace that as well. I believe that the resistor at the LD4 gate led is bad, I also looked at r37, r44, r45 which were all clipped. The motor runs with the alternating plus and minus switches in debug mode but the led shuts off as it is getting to full speed, thereby shutting off power to the motor.
Please advise. Thank you
 

mcbeasty16

Joined Jun 1, 2022
2
I've been working on a HealthRider R60 (Model HCTL07120) treadmill that had been plugged into an improperly-wired outlet and, consequently, got a brief dose of 277VAC. The main fuse on the power board blew, obviously, so I replaced it. Once it was replaced, all of the controls on the treadmill started getting power, but if I tried to start the treadmill, it would only run for about half a second and then stop. I would then have to press STOP in order to try to start it again, but I get the same result.

Based on the activity of the LEDs on the power and motor control boards, I'm fairly confident that the remaining issue is on the motor controller board (Model MC-2000H).

I have no formal training in electronics repair, although I do have a great deal of experience with soldering, so the effective limit of my repair ability is visual inspection and replacing clearly damaged parts.

Upon inspecting the motor control board, I found that the MOV that's located immediately after the incoming AC voltage had violently failed (half of it ended up three inches away). I painstakingly identified, researched, sourced, and ordered an equivalent replacement MOV and soldered it onto the board in place of the failed MOV.

I naively expected the treadmill to fire right up and function normally once I powered it on, but it now behaves precisely as it did before I replaced the MOV.

As I said, I lack the formal training and knowledge to know how to proceed or troubleshoot the motor controller from here, so this is mostly a shot in the dark to see if anyone might be able/willing to at least point me in the right direction.

Please excuse my ignorance and presumptuousness in even asking for help here. I've always thought that it was rude when people online just stumble into a forum of experts and ask for help with something that should be elementary to anyone with even a passing familiarity with the forum's subject, but I'm on the hook to fix this treadmill and can't afford to replace the motor controller.

Any assistance would be GREATLY appreciated.
Wanted to see if I could confirm some components on the board before ordering as I experienced a similar issue.
The throughhole leads on R44 and R45 of my board seem to have blown off past the point where I can recover them, at least with my poor soldering skills. I was able to recover R37 and it seems to test good, but I am not confident in the other 2. The two troubled resistors can be found in the bottom left corner of my attached photo.
Based on my observations, (I could have read these color bands incorrectly) R44 is a 7.5MOhms 10%, and R45 is 3.6MOhms 5%. I don't know how to determine the power rating, I know that size typically determines that though. Was not able to find consistent information online.
Here's hoping that people are still experiencing issues with this and will take a look! Thanks for any assistance.
 

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mcbeasty16

Joined Jun 1, 2022
2
Sir, I have the exact problem you have, what components did you replace? I did replace the resistors and the coiled 7v resistor was running very hot so I did replace that as well. I believe that the resistor at the LD4 gate led is bad, I also looked at r37, r44, r45 which were all clipped. The motor runs with the alternating plus and minus switches in debug mode but the led shuts off as it is getting to full speed, thereby shutting off power to the motor.
Please advise. Thank you
Sounds like we had the same observation with r37, r44, and r45. Mine all tested good, but was going to solder them back on and give it a test.
 
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