# Horizon CT12.1 Treadmill troubleshooting. (SJED08066AA PWM controller JDYF01L)

#### Kalvin

Joined Jan 1, 2017
13
Hi,

I found this site while searching the web for information for troubleshooting a treadmill problem.

The treadmill is a Horizon CT12.1. I believe it is made by Johnson Fitness and labeled under a couple different names. Another version of this is the Livestrong LS12.9T I'm thinking the CT stands for a Canadian Tire, a store in Canada that sells(sold) this model.

It looks like the one shown here. http://www.runreviews.com/wp-content/uploads/2011/03/horizon-CT12.1-treadmill-review.jpg

Now on to the problem.

With the unit plugged in, I can turn it on and the unit appears to go into its boot up state. Three long beeps and the center screen displays "301 01" on top line, "MILE" on second line and "CT" on third line. Then two shorts beeps and all indicators and leds on control panel light up. After this nothing can be controlled. Every startup is the same.

The first thing I though is this might be related to the safety key. It is a copper tab type key that slides into a set of contacts to close a contact. It had a very high resistance on some inserts and no resistance on others. Cleaning the copper key and contacts brought it a clean closed contact every time, but with the same start up results. Not the safety key.

Next was to take a fast look at the two boards. The upper control panel board on visual examination looks to be ok. No obvious signs. This board is marked
SUH08012PB (DT999&1399) BY TFJ 09/03/26 All conections appear to be connected.

The PWM controller board is marked JDYF01L Johnson Fitness on the pc board and there is a label on the heat sink (which is part of the board assy.)
Marked 2.75 HP 110V JC02-001 SJED08066AA Ver H102S101 JC02MC100aa005278. It appears fine on visual inspection also.

There are five red leds on this board. Four in a group. These four do not light up at any point in the boot up sequence. Two of these are labeled UP Down. Probably for the incline actuator.

The fifth LEd is behind the three large capacitors and can not be seen in the photo. It lights up on power up and remains on. From reading I believe this indicates live rail voltage. After power down it remains on until the circuit bleeds down.

There is a 12 wire harness that runs from the control panel to the PWM controller board. Seeing the treadmill has a tilting stowage function, I figured I would check the harness. There are no opens lines on any of the 12 wires from the control panel to the PWM controller.

This 12 wire harness appears to be common on a fair number of these types on controllers. Does anyone know what each line is for? I'm sure a couple of them are power. If you unplug the 12 pin connector and try to power up the unit nothing happens on the control panel at all. I was curious because I had seen a smaller board near the PWM controller that was directly connected to the 120V in and it had two wires coming off of it and up to the upper control panel. I assumed it was the power source for the upper control panel.

I'm sure that upper controller board is looking for certain things in it's boot up. I just have no idea what they might be. It would be nice to know what data is on the 12 wire harness. I've looked around and it appears these PWM controllers are common, but no pin outs. If I was designing it I would most likely have one line as a heartbeart, if it wasn't there I would not let it boot up. A couple more for the PWM signal?

Any other ideas?

Thank you in advance.

Kalvin

#### Kalvin

Joined Jan 1, 2017
13
Well, three years later almost to the date and I figured I would give this a try again. This unit has been sittting idle in my garage.
Anyone has a schematic of the JDYF01L control board? I think I'm going to pull the board tomorrow and start going through the components 1 by 1.

#### GlennRic

Joined Nov 1, 2020
2
I have the same model (CT12.1) with exactly the same error message and behavior as yours.

I was able to get the unit into Engineering Mode and run the Auto Calibration sequence. This runs the belt through all possible speed values. This test did complete normally, so the problem is not with the motor or the motor control board. I also checked the wiring harness and it's fine. Thus, the only remaining point of failure would be the upper control board.

According to Johnson Fitness (https://parts.johnsonfitness.com), the upper control board (UCB LS12.9T HBS104-10) costs around 350 US$. A quick search around the web confirms this price. I purchased the treadmill on sale around eight years ago for around 900 US$ so 350$is a pretty steep repair bill -- especially considering that I have no guarantee it'll fix the problem. I was just wondering if you had made any progress in your investigation. Frankly, I'd be happy if I could set the treadmill to operate at a fixed speed and just leave it like that until the motor dies. Thread Starter #### Kalvin Joined Jan 1, 2017 13 I have the same model (CT12.1) with exactly the same error message and behavior as yours. I was able to get the unit into Engineering Mode and run the Auto Calibration sequence. This runs the belt through all possible speed values. This test did complete normally, so the problem is not with the motor or the motor control board. I also checked the wiring harness and it's fine. Thus, the only remaining point of failure would be the upper control board. According to Johnson Fitness (https://parts.johnsonfitness.com), the upper control board (UCB LS12.9T HBS104-10) costs around 350 US$. A quick search around the web confirms this price. I purchased the treadmill on sale around eight years ago for around 900 US$so 350$ is a pretty steep repair bill -- especially considering that I have no guarantee it'll fix the problem.

I was just wondering if you had made any progress in your investigation. Frankly, I'd be happy if I could set the treadmill to operate at a fixed speed and just leave it like that until the motor dies.
Hi GlewnnRic,

I did not make any progress. It is still sitting there. I was actually looking at it the other day thinking I should get it ready for winter. I have been watching the local buy and sell sites in case a parts machine pops up.

Could you tell me more about the engineering mode? Maybe I can eliminate my motor and motor controller board.

I think the upper control board would be easy to work around or repair.

Kalvin

#### GlennRic

Joined Nov 1, 2020
2
Hi Kalvin -- sorry for the delay. Here's the guide for engineering mode:

Engineering Mode

Power on the treadmill and have the safety key in position on the console. Press and hold the elevation “+” and speed “-” for about 5 seconds to enter the Engineering Mode Menu. The console should beep three times and Eng0 should be displayed once in the Engineering Mode Menu.

Press and hold “Stop” to exit all engineering modes.

Eng0 – Display and Button Check

1. While in the Engineering Mode Menu, press Speed “+” or “-” until Eng0 appears in the display.
2. Press “Enter” to select Eng0.
3. Press “Start” button to verify all LED’s
Eng1– Hardware Test
1. While in the Engineering Mode Menu, press Speed “+” or “-” until Eng1 appears in the display.
2. Press “Enter” to select Eng1.
3. Press “Start” button to verify belt movement, sensor wire, and elevation function.
Eng2 - Auto Calibration
1. While in the Engineering Mode Menu, press Speed “+” or “-” until Eng2 appears in the display.
2. Press, “Enter” to select.
3. Press, “Start” to begin.
# The treadmill running belt will begin moving and will automatically begin the auto-calibration sequence to properly set and store the speed values.
# Upon successful calibration there will be four beeps and it will automatically exit Engineering Mode and will return you to the original screen.
Eng3 – Software Setup
NOTE:
Using incorrect software settings will result in erratic speeds, incorrect button function, etc.
1. While in the Engineering Mode Menu, press Speed “+” or “-” until Eng3 appears in the display.
2. Press, “Enter” to select.
3. Press, “Enter” to change software version. Each time the select button is pressed, a number will change in the upper right hand corner (ex. 1-10). This number represents the number of programs for that software version. The settings are as follows:
1-10 = T64
1-8 = T63
1-6 = T62
1-4 = T61
You can only change software version for the T61-T64 Models.
4. Press, “Start” to change the distance parameters between miles and kilometers. This number is shown in the upper left hand corner of the display. 0 represents miles and 1 represents kilometers.

#### Kalvin

Joined Jan 1, 2017
13
OK, I'll try this and post back here. (Might take a day or so)

I'm going to need to reassemble a few things to test this, but it is worth a try and can eliminate a few items.

Thank you.

#### Kalvin

Joined Jan 1, 2017
13
Hi GlennRic,

I had a little time to play this evening. I could not get mine to go into the engineering mode.

I tried holding the elevation + key and the speed - key with no joy. I tried the keys on the console and the keys on the bar extensions on the sides. I also tried elevation - and speed +. I tried numerous different combinations with no luck.

I was not clear if you waited until the unit had gone thru its full power up and after the two beeps and all the indications were lit up. So I also tried at various points. Right after the three long beeps and the 301 page , etc. Still no joy.

I was really hoping to eliminate the controller board.

I did do a little exploring around and figured out that little board in my last photo. It appears to be a 12VDC power supply that leads up to the console. At the console it looks like it powers a small board that deals with the audio to the console speakers for music. Disconnecting it does not affect the upper console operation. This is good. It tells me 2 of the 12 wires going up to the console must be power. Only 10 more to figure out.

Just to confirm, you unit has the exact issue mine does?

" Three long beeps and the center screen displays "301 01" on top line, "MILE" on second line and "CT" on third line. Then two shorts beeps and all indicators and leds on control panel light up. After this nothing can be controlled. Every startup is the same."

I wondering why I can not get into the engineering mode? Where did you find the info on accessing the engineering mode?

Thank you Kalvin

#### Kalvin

Joined Jan 1, 2017
13

#### Kalvin

Joined Jan 1, 2017
13

#### Kalvin

Joined Jan 1, 2017
13
This might be easier to see.

#### Kalvin

Joined Jan 1, 2017
13
GlennRic,

Do you remember your normal boot up sequence before your unit started to have issues?

#### Kalvin

Joined Jan 1, 2017
13
Ok I'm still plugging away on this.

I'm taking a guess the upper control board is my fault. I was unable to get into the Engineering mode.

I'm assuming on power up the three long beeps and the center screen displaying "301 01" on top line, "MILE" on second line and "CT" on third line is normal boot up.

The two shorts beeps and all indicators and leds on control panel lighting up is not. The two short beeps might be an error code?

I though maybe something was preventing the upper board boot up, so I disconnected all the connectors I could to the board and it still powers up the same way.

I now have the upper control board out of the unit, on the bench. Supplying it with 16VDC gets the same results.'
This may be repairable, but I think my time is better spent working on an alternative control.

So, my plan now is to build my own controller using an Audrino/ESP32/ or something similar.

From a lot of reading I have learned a few things. Mostly from IamJatinah. Thank you.

Correct me if I'm wrong.

For my controller to enable the motor control board.......

1 First send enable signal (pin 10 white). 5VDC ?
2 Start PWM feed signal (pin 9 grey) . What frequency is the PWM signal send at?

Seeing I am still using the controller in a treadmill the motor speed sensor is still wired up and the belt pulley sensor is also still attached. This should complete the rest of the input signals required for the start up to work. Before 1.5 seconds the motor controller expects to see movement on the belt pulley.

Once the start up has passed, I should also then gain control of the incline up and down part of the motor controller.

There might be some timing checks on the motor control board that checks the enable signal and expects to see the PWM signal within a certain time.

Can anyone help me out with the PWM frequency I should be using? Once I get this I can wire up a test circuit to see if I can get the belt to move.