Horizon Treadmill T81. Main motor will not run

Thread Starter

paulbond

Joined Dec 3, 2016
5
I have a Horizon T81 treadmill in excellent condition that I acquired in a non-running state. When I got it home, after checking all connections, it did initially work for a couple of minutes. I then transferred it into the house and it hasn’t worked since!! Everything looks good except that the belt motor does not run. Incline function is ok. No error codes when attempting normal operation.


Upper console lights up, I was able to access engineering mode and test seem to indicate everything ‘up top’ works ok. Auto speed calibrate does not drive motor. Gives E1 error I have tested the belt motor itself using a 12V battery and it works fine. There is no voltage output from the motor drive terminals on the board.


At the moment everything suggests to me a problem with the motor control board. I removed the control board, refreshed the solder connections on the board, checked diodes etc but haven’t found anything obvious so far. Did not change the symptoms. Without a schematic it is difficult to go further.


I’ve been looking for a replacement control board. Sites say that I need a 032671-HF whereas the one currently fitted is a SJED08092HF ver:H108 S106. They look to be physically identical as far as I can see from the photos but would like confirmation.


I understand that there may be someone who can repair these control boards. Could you advise me:


1. Is there anything else I should try?

2. Would you be willing to repair this board and, if so, at what cost, time?

3. Would anyone have a suitable replacement board for advance exchange?
 

Thread Starter

paulbond

Joined Dec 3, 2016
5
Usually the output transistors\mosfets go.

1: Make sure the running belt is in good condition, has correct tension, is square to the rollers, lubricated (silicon spray is the thing to use) and runs freely.
2: Check the board underneath the running belt is in good repair.
3: Check all the bearings on the long rollers.
4: Check the motor belt is in good repair, has correct tension and is sitting on the pulleys correctly.
5: Vacuum the area when the motor & controller are, dust is a concern. It can over heat the motor & cause shorts if it absorbs moisture.
6: Be aware this can be a frustrating endeavor.
7: Have the machine serviced regularly or learn to do it yourself (a user manual should give you the basics).
8: Keep the machine clean, wipe it down after every use and occasionally give it the once over.
9: As much as possible try and minimise the dust.
10: Upon noticing any excess heat, strange noises or smells don't keep using it, investigate the cause.
 

Thread Starter

paulbond

Joined Dec 3, 2016
5
Thanks for your suggestions, will give them a try. Repair of the board would be much easier with a schematic but not having much luck there.
 

hella

Joined Jul 23, 2017
7
Hello. Sorry I can't make a new thread.

I have a Horizon Quantum II treadmill. It starts up intermittently.
It usually does not cold-start at low speed like 0.5. It is easier to start at higher speed like 2.5 (Or it can cold-start at speed of 2.5). When it is already warmed up, it can start at any speed. If it does not start, an E1 error will be appeared after 10 seconds.

Any suggestion or recommendation are highly appreciated.
 

MaxHeadRoom

Joined Jul 18, 2013
22,364
Ensure all belts are clean and the main belt lubricated, does it have a RPM detector on the back of the motor? Usually an optical or hall effect device.
Max.
 

hella

Joined Jul 23, 2017
7
Ensure all belts are clean and the main belt lubricated, does it have a RPM detector on the back of the motor? Usually an optical or hall effect device.
Max.
Thank you for quick reply. Yes, it does have RPM detector. I did clean the surface of this detector. I think the detector is working fine because even it does not start, if I moved the belt by hand then the E1 error won't appear until the belt stopped.
 

IamJatinah

Joined Oct 22, 2014
130
I think you want to remove the belt from motor to pulley and run the motor. I may try to do it later
Hi All, Horizon Quantum will be the Horizon 013674-DG board in most cases unless quite old. This is a troublesome controller, all discrete design and touchy to service. The problems you describe lead to that MCB or lower board. Tell us, is there 2 large input capacitors on that board, or just one? If one, that board needs service including replacing the sole storage cap, and/or adding another storage cap where it is screened for one but it wasn't populated due to a cost-down ECO, which failed field tests miserably.
When the tread starts oddly like this, it could very well be trying to overcome inertia, cold, and using considerable current, which then may trigger foldback or current limit to protect the MCB. Bad motors can also cause this symptom, burnt or shorted windings, bad bearings or a seriously sticky deck/belt situation. This Quantum design experienced a recall in maybe 2002-2004 era that caused the manufacturer, who I once worked for, to substitute this 013674-dg board in place of the recalled original A-Star branded MCB. The E1 error matches the odd belt speeds being referenced to a speed table in the console. This particular controller is SCR controlled as well! For example, this unit powers up to console power. When Start is pressed, a safety relay will "click" or engage, supplying "Bulk" power to the SCR, as rails rise and stabilize a signal is sent to the opto that drives the gate of the SCR, turning that SCR "ON", and now providing a full path for raw Bulk motor power.
This trigger to the Opto does fail at times and is a bit tedious to troubleshoot, which must be done with full power applied to the unit on the bench. There are also a couple of small potentiometers on the little lower board of the MCB, one being a "Torque" pot and the other "Speed" for adjusting things during calibration and set up. You can try to turn them to the right, CW, to about 3/4 full turn and retry things. Never set these pots full On for reasons that would bore most. So, maybe next time you try the machine, listen for that "Click" after hitting Start. If no click, there could be troubles with a cable or console connection. You can contact me for further help if needed at jatinahATrocketmailDOTcom.
 

hella

Joined Jul 23, 2017
7
Hi Lam,
Thank you for your post.
My MCB has one big cap only.
I tried to turn 3/4 full turn either small potentiometers but did not help. The issue is still there. There is a "Click" after hitting "Start" then E1 appeared after 10 seconds.
Please advise if I can replace one big cap by two small caps.
Thanks.
 

Attachments

IamJatinah

Joined Oct 22, 2014
130
Hi Lam,
Thank you for your post.
My MCB has one big cap only.
I tried to turn 3/4 full turn either small potentiometers but did not help. The issue is still there. There is a "Click" after hitting "Start" then E1 appeared after 10 seconds.
Please advise if I can replace one big cap by two small caps.
Thanks.
Hi There, Thank you for that pic. This is the old-style Quantum controller. There is room for only one cap on this older style of PCB and the controller looks to be in good shape. Have you checked the main switching FET under that aluminum bracket? This hold the FET tight to the metal frame (heatsink) of the unit. Next to that is a small kickback diode rated at 15A that was changed to a 30A device years later for the same motor sets, so if replacing parts we want to increase the main switching FET from IRFP250 to IRFP260N or better, we use 75A TrenchFETs for most controllers. That kickback diode should also be changed to a 30A, 600prv part during any service. I might think there is a shorted FET on this board. When this FET shorts, it will sense the short and hold-off the SCR, not allowing for any motor power. If this FET shorts, it will most often take out the kickback diode instantly, as well as some other parts on that board which I won't get into as that dives into the discrete sections of the hot-drive circuits and folks can get hurt playing in that part of the circuits. We do still repair these if needed you can contact me at jatinahATrocketmailDOTcom for help, or you can also look for the newer style of Horizon controller that drops in for this as a replacement, under Horizon/Johnson part number 013674-DG, which will come with a new transformer as the old one will not connect to the new board as there are dual outputs on the new transformer verses the single output transformer you currently have. Good Luck!
 

R!f@@

Joined Apr 2, 2009
9,746
By the way, an E1 could be the motor RPM sensor issue.

If the motor starts slowly and stops after a few turns without picking up speed then there is no shorts on the MCB as far as I can tell.

You need to check the motor speed sensor before doing anything else.
 

IamJatinah

Joined Oct 22, 2014
130
By the way, an E1 could be the motor RPM sensor issue.

If the motor starts slowly and stops after a few turns without picking up speed then there is no shorts on the MCB as far as I can tell.

You need to check the motor speed sensor before doing anything else.
Hi All, I think hella tried pushing the belt and noticed a delay or no error shown which may mean the feedback is there. If you press start and there is "no" belt movement for 1-3 seconds, the issue will most likely lie in the drive signal chain or main motor switch on the lower board. If the sensor is missing or bad, that walking belt will move for an instant until the upper finds no feedback match. E1 is a generic error displayed when a "mismatch" of expected to actual return is checked ;o) This particular controller watches a front roller and not a motor encoder wheel. These front roller signals are quite slow compared to most other signals, and the upper must allow some movement to validate motion and speed sense.
 

hella

Joined Jul 23, 2017
7
By the way, an E1 could be the motor RPM sensor issue.

If the motor starts slowly and stops after a few turns without picking up speed then there is no shorts on the MCB as far as I can tell.

You need to check the motor speed sensor before doing anything else.
Hi All, I think hella tried pushing the belt and noticed a delay or no error shown which may mean the feedback is there. If you press start and there is "no" belt movement for 1-3 seconds, the issue will most likely lie in the drive signal chain or main motor switch on the lower board. If the sensor is missing or bad, that walking belt will move for an instant until the upper finds no feedback match. E1 is a generic error displayed when a "mismatch" of expected to actual return is checked ;o) This particular controller watches a front roller and not a motor encoder wheel. These front roller signals are quite slow compared to most other signals, and the upper must allow some movement to validate motion and speed sense.
@lamJatinah: you are right. The sensor is working.
 

hella

Joined Jul 23, 2017
7
Hi There, Thank you for that pic. This is the old-style Quantum controller. There is room for only one cap on this older style of PCB and the controller looks to be in good shape. Have you checked the main switching FET under that aluminum bracket? This hold the FET tight to the metal frame (heatsink) of the unit. Next to that is a small kickback diode rated at 15A that was changed to a 30A device years later for the same motor sets, so if replacing parts we want to increase the main switching FET from IRFP250 to IRFP260N or better, we use 75A TrenchFETs for most controllers. That kickback diode should also be changed to a 30A, 600prv part during any service. I might think there is a shorted FET on this board. When this FET shorts, it will sense the short and hold-off the SCR, not allowing for any motor power. If this FET shorts, it will most often take out the kickback diode instantly, as well as some other parts on that board which I won't get into as that dives into the discrete sections of the hot-drive circuits and folks can get hurt playing in that part of the circuits. We do still repair these if needed you can contact me at jatinahATrocketmailDOTcom for help, or you can also look for the newer style of Horizon controller that drops in for this as a replacement, under Horizon/Johnson part number 013674-DG, which will come with a new transformer as the old one will not connect to the new board as there are dual outputs on the new transformer verses the single output transformer you currently have. Good Luck!
Do you have any idea which FET is shorted? Or do you recommend any troubleshoot to find out the shorted one?
 

IamJatinah

Joined Oct 22, 2014
130
Do you have any idea which FET is shorted? Or do you recommend any troubleshoot to find out the shorted one?
Hi There, There is only one main switching FET on that unit, which is mounted to the heatsink/frame of the controller with a metal bracket, near the white current resistor standing up on the board, maybe marked 1.75hp on the side, which related to the factory stamp for the current sense resistor value to install. It may have been mentioned earlier, that if the main FET is blown or shorted, that kickback diode next to it will also be damaged. Both parts are a bit sketchy in this design and should be updated to a 35A FET and 30A 600v(prv) Ultra-Fast kickback, which also must stay isolated from that case or things will rip apart at power up. That motor rail resides on a "Hot Ground" and shorting the kickback to that case will release trouble in a huge way. Finally, if these 2 parts are ripped/shorted/blown, there will most likely be more issues long the drive-chain, thru the predriver circuits usually, and this is an all discrete design, one I cannot advise others to play with. I have spent at least a decade repairing these style of controllers, and I can tell you with certainty, if a single thing is missed during bench troubleshooting, a servicer can expect a large rip and smoke from the controller at full-load testing. I am used to it, most other would not be, nor would they maybe be prepared to power-down a hot-bench in a fast way to clear away that blast zone ;o) These boards, upper and lower of the controller, must be pulled apart to service, which is a tender job as well, as one missing or intermittent header pin, 40-connection points, or connection between boards will again cause major troubles. This is one of the "can't suggest folks try this at home" units. That motor rail bulk voltage sits at +165vdc for US models, and that bites terribly hard.
 
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