I also had to replace the "disconnect" style crimp-on connectors which connect to the motor as the plastic housing on the existing one was completely melted from when it failed.
View attachment 108386

Would you be able/willing to share how you replaced the white plastic (melted) connectors? I have a similar failure and am not certain if there exists a replacement part to isolate the two cables/connectors.

 

Would you be able/willing to share how you replaced the white plastic (melted) connectors? I have a similar failure and am not certain if there exists a replacement part to isolate the two cables/connectors.

Hi There, everytime I hear of these connectors melting down, I must warn people that this is an indicator of high current flow thru those connections, heating them up beyond safe levels. Just fixing the wires will only lead to a dead controller soon, as either that motor control board is running very hard, deck/belt has not been lubricated and needs it, or the motor has active shorts in the winding sets.

 

Hi there! I got this same board for repair with a few smd resistors open around the 3842 chip. After a Google search I landed on this page and Silmarillion's pictures helped a lot in identifying them except one which appears covered in glue.

It is R21, the remains of the legend on it seem to read 2001, but I'm not sure. This resistor connects R17 current sense resistor to current sense lead of 3842 chip. I've seen 3842 datasheet and Application Notes and they seem to use 1K resistors. R17 is a 1% resistor so I'm not sure whether R21 needs to be exact.

Would anybody please help me with this? I'm impressed with IamJatinah's knowledge. He has mentioned many things I didn't know which I will certainly take into account.

Thanks in advance

Rlarios

 

Hi there! I got this same board for repair with a few smd resistors open around the 3842 chip. After a Google search I landed on this page and Silmarillion's pictures helped a lot in identifying them except one which appears covered in glue.

It is R21, the remains of the legend on it seem to read 2001, but I'm not sure. This resistor connects R17 current sense resistor to current sense lead of 3842 chip. I've seen 3842 datasheet and Application Notes and they seem to use 1K resistors. R17 is a 1% resistor so I'm not sure whether R21 needs to be exact.

Would anybody please help me with this? I'm impressed with IamJatinah's knowledge. He has mentioned many things I didn't know which I will certainly take into account.

Thanks in advance

Rlarios
View attachment 237454

should be 2k. if other smd resistors are blown in that circuit, replace the 3842 and check the fet well ;o)

 

Thanks IamJatinah! That certainly helped a lot. I replaced the resistor and power supply came back on. I didn't have the user panel hooked up, so as soon as power supply came on, main relay clicked on and red LED lit fully on as well. I could measure 16V and 5V on this power supply so I turned it off and handed it to the technician who brought it to me so he could put the treadmill back together.

However, after this guy did the installation and once the unit was back together, it didn't come on. The red LED was not fully on. He brought it back to me days later and I noticed the 3842 chip was not working, no pulses going to the mosfet because voltage reference pin 8 was shorted to ground. I replaced 3842 chip and same results with LED not being fully on, there were 16V and 5V, though. Then I noticed magic smoke coming out near power supply mosfet and quickly turned it off. I replaced mosfet and power supply came back on and no smoke this time. However, no relay clicking, red LED still half lit. I checked where this relay signal came from and sure enough I tracked it back to PIC microcontroller. Apparently microcontroller is not running. /MCLR signal is ok at 5V after a few milliseconds of power being applied. Oscillator signal ok at 20MHz on pins 9 and 10. Upon checking signals coming from optocouplers, I noticed a steady 5V voltage from P521. Then, checking voltage on LM339s power leads I saw 0V. I followed power line back to its source and found a physically broken 18V Zener and an open rectifier coming from one winding of the transformer I was unaware of. The rectifier was the source of the magic smoke I had seen before. I replaced diodes and now there was voltage on LM339s power rails again and voltage coming from P521 was low going to the PIC microcontroller. But still no relay clicking at all. Upon checking all PIC lines with oscilloscope I see no activity there. Oh! I forgot to mention that user panel display beeps like three to four times at power on while showing 503 on one of the displays. I am under the impression PIC microcontroller may be either dead or one of the feedback signals is missing.

Any idea as to where else to look to bring this unit back from the dead?

Thanks for any help you may provide.

Rafael

 

Well, this is what happens when one is not familiar with a piece of equipment. I found out why it didn't work, although it started differently compared to what I perceived the first time. Probably because the power supply was still faulty.

It happens that I once accompanied the technician to see how treadmill worked with power supply "repaired" but I was still unaware of bad rectifier D7 and Zener diode D6. That day, the technician showed me that there was some sort of magnetic key that had to be placed on top of user panel. That day, elevator motor worked but main motor didn't.

As I don't have the key now, I removed the magnetic switch female conector and shorted the pins on male conector on the board with an alligator clip, and even though 503 still appears upon power on, this time after pressing start, relays clicked and LED came fully on!

I guess the rest will be left to the technician once he puts the treadmill back together. I will check the signals on the PIC microcontroller to satisfy muy curiosity before this goes to its owner.

Thank you very much to all participants in this thread, especially to IAMJatinah because without his detailed explanation I wouldn't have been able to persevere to fix this. Many thanks also to the original poster Silmarillion, because without his pictures finding out the values of blown SMD resistors would have been next to impossible.

BTW, excellent forum!

Rafael

 

Well, this is what happens when one is not familiar with a piece of equipment. I found out why it didn't work, although it started differently compared to what I perceived the first time. Probably because the power supply was still faulty.

It happens that I once accompanied the technician to see how treadmill worked with power supply "repaired" but I was still unaware of bad rectifier D7 and Zener diode D6. That day, the technician showed me that there was some sort of magnetic key that had to be placed on top of user panel. That day, elevator motor worked but main motor didn't.

As I don't have the key now, I removed the magnetic switch female conector and shorted the pins on male conector on the board with an alligator clip, and even though 503 still appears upon power on, this time after pressing start, relays clicked and LED came fully on!

I guess the rest will be left to the technician once he puts the treadmill back together. I will check the signals on the PIC microcontroller to satisfy muy curiosity before this goes to its owner.

Thank you very much to all participants in this thread, especially to IAMJatinah because without his detailed explanation I wouldn't have been able to persevere to fix this. Many thanks also to the original poster Silmarillion, because without his pictures finding out the values of blown SMD resistors would have been next to impossible.

BTW, excellent forum!

Rafael

The pleasure is all ours, well done ;o)

 

HI Folks, your're correct, the FET and kickback diode have died. Please also check the 22ohm resistor leading to the FET gate as it can be taken out during a FET short, and also there are a "push-pull" set of transistors, maybe labelled Q6-Q7, small SMT transistors next to the FET should be checked as well.
Testing can ONLY be done in the treadmill unless you supply 2 feedback signals to the UUT(board) during testing to satisfy the PIC chip, controller CPU. Lastly, during FET shorts, there is also a tiny 220ohm resistor that can open near an output filter cap leading to an opto-isolator which is the drive line for the PWM speed signal.
Let us know how the repair goes, parts are available at Mouser or Digikey for these repairs. Good Luck! greg

Hi there IamJatinah,
I found this post from you and determined on my brd that both Q6 and Q7 were baked ... Q6 was visually burnt ... Q7 looked fine but has problems. Also that 220 ohm resistor for the opto was open as you have mentioned ... circuit reference is R48 and sits right beside one of the smaller filter caps covered in white silicone.
My question for ya is ... what does a guy replace Q6, Q7 with ... parts numbers ?
This is what I managed to get matched up for them ... BBH (pnp?) equivalent is KTC9012S which is unavailable and found at Digikey ... https://www.digikey.ca/product-detail/en/2SAR502UBTL/2SAR502UBTLCT-ND/5019142?itemSeq=378018781
and is 2SAR502UBTL.
BCH which I think is the npn ... can't see on mine as the top was burnt but found another poster who said his was BCH.
Match I found for BCH at Digikey is KTC9013S also unavailable but Digikey had this ...
https://www.digikey.ca/product-detail/en/2SCR502UBTL/2SCR502UBTLCT-ND/5019148?itemSeq=378018759
and is 2SCR502UBTL
They are both 30v 500mA bjt's matching npn/pnp pair.
Let me know if you can if I got it right ... please !

Journey11

 

If you don't run the motor it should be OK to hook power to the board for testing, that board is not among the ones I have schematics for, in many cases schematics exist on the web due to some one taking time to reverse engineer the board.
Max.

Hello Max
Can you please send me schematic drawing
Thanks
Abib

 

The only ones i have are for the MC2100 & MC-60
Shown here.
https://forum.allaboutcircuits.com/...or-control-circuit.100678/page-2#post-1267375

 

Hi freinds
I have a “jdyf07l revi” horizon motor control board and i need part name of 8 pin U4 opto-isolator (its part name covered by glue and unreadable) , could anyone help me?
Thanks alot

 

Hi freinds
I have a “jdyf07l revi” horizon motor control board and i need part name of 8 pin U4 opto-isolator (its part name covered by glue and unreadable) , could anyone help me?
Thanks alot

It seems to be:

"Description:
6n138 DIP-8 High Speed OPIC Photocoupler
LOW INPUT CURRENT HIGH GAIN SPLIT DARLINGTON OPTOCOUPLERS
http://www.vishay.com/docs/83605/6n138.pdf"

I got it from someone else in the thread. Read it through, you will find very good information in the thread.

Rlarios

 

Hi, have a Horizon CT83 with JDYF02L Rev g and 2.5Hp motor.
Will run for various amounts of time and then display will just shut down.
Sometimes it will come alive again and allow for operation.
Also noted that display can take up to 20seconds to light up after first connecting power.

I pulled controller board and did not find anything obvious.
All diodes appear ok but replaced main FET and “sinked” diode thinking something might be weak.
Same behaviour…runs for a bit then display shuts down.

I do not expect motor thermal problem, as it can happen while it sits (not running belt).
Reading thread, im unsure if the uP is getting all feedbacks and not enabling ”system”.

appreciate any assistance.
steve

 

Hi there,
I am looking for some assistance troubleshooting this board (or at least determining if it's out of my league :>). I have found a number of similar motor control board issues on here, but nothing specific to this particular one. Other possible relevant info from the board: 2.25-2.5 JC07-001 SJED08089IF Ver H109S106

Description of the issue: The treadmill had stopped and requested a belt lube (we have done this before, but it has never actually come up with the maintenance message). Lubricated the belt & did a thorough cleaning, reset the maintenance message, put it all back together & worked OK. I had started using it again, and noticed that the belt was slipping when I got it slowed down to a walk speed (wasn't happening (at least noticeably) at higher speeds). I was going to finish my workout and try adjusting the belt tension, when it made a popping noise (combined with a glitch on the TV), the belt motor stopped, and I could smell the magic smoke :>)

Troubleshooting done so far: I used some of the very helpful information on the Treadmill Doctor site to narrow down the issue. I tested the motor with a battery - still works. The control panel, elevation motor, etc. still work, and Treadmill Doctor indicates the issue is the motor control board. The red LED on the board does not light when everything is connected. I have removed the board from the aluminum mounting plate / heatsink, did a visual and "sniff test", but I don't see anything blatantly obvious (burned components, bubbled caps, etc.). I did a bit of poking around and *may* have found one bad diode, but apparently had a brain fart and forgot to document it...

My skill set: I have decent soldering skills & tools, and basic electrical / electronic knowledge. Although I did electronics as a hobby when I was younger, and went to school for electronics, that was in the 80's, and my jobs have been in IT. I could do some basic component testing / replacement with some help / direction. I would just replace the board, except for the cost (I was recently laid off, and am trying to conserve funds), and the concern that a replacement board may wind up in smoke as well, particularly if I am still having issues with the belt. The treadmill is a few years old, and I am not sure if the board is worth the cost to replace for the value of a used treadmill.

So whatever guidance anyone can supply would be greatly appreciated. Concern with repair is the amount of time and effort involved to make sure I get everything if there are multiple components damaged, with getting components, and with sinking a bunch of time and money into a project that is over my head, or possibly not fixable (at least by me :>).
I don't take offense easily, so please feel free to be candid with comments (but hopefully avoiding outright insulting :>). This looks like a great community with some very helpful members - thanks in advance, even if just for the information I have already found on here. I have added a couple of photos as per what I have seen in the other threads.

Thanks!

View attachment 84690
View attachment 84691

Could any one kindly let me know the resistance value of R7 SMD resistance and what are the possible reasons for it to blow?

 

Zener diode D6

Rlarios
Could you kindly give me specifications of this diode?

 

bad rectifier D7

@Rlarios
Could you kindly give me specifications of this diode?

 

What is the model of the board?

 

What is the model of the board?

Johnson Fitness JDYF02L REVg
Thanks for asking and attempting to help.

 

Rlarios
Could you kindly give me specifications of this diode?

D6 = BZX55C18

 

@Rlarios
Could you kindly give me specifications of this diode?

D7 = HER107

I haven't seen any board like this since last year. You're lucky I keep notes!

My pleasure to help just as they helped me back then.

Cheers!

rlarios