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  #1  
Old 04-04-2010, 08:35 PM
CaptainMAD CaptainMAD is offline
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Default Horizon treadmill - motor control board problem

Hi,

Before I explain my problem, please note that I am not an electronics engineer, but like to tinker - and have a BASIC understading of electronics.

Now onto my problem :-)

I have a Horizon Paragon 2 HRC treadmill with a 013674-DG motor control board. The treadmill lights up as normal, incline function operates fine, BUT belt motor will not start.

I removed the leads to the motor from the control board and connected my multimeter. There is 19v DC at the motor terminals when the treadmill is turned on but not running - when "Start" is pressed on the treadmill, the voltage rises to 20.5V DC. I tested the motor with a 24v DC 15A supply (which I made from an old ATX PC Power supply - thanks instructables.com) and it spins ok, so I'm pretty confident the motor isn't the problem.

I have checked all the diodes in circuit (in situ) and they appear ok (readings one way, open circuit the other - checks one on the diode setting on the multimeter). If I increase the treadmill speed the voltage at the motor terminals doesn't increase (which I presumed it would, to make the motor increase in speed - as the belt motor is rated 180V DC).

Can anyone give me any insight as to what components to check next, or have had a similar problem and found a solution?

I have also noticed, on the board between the two large capacitor are two LED's. The one nearest the motor spade terminals is illuminated (but not at full brightness) when the treadmill is turned on, but not running. When running the LED goes out. The LED nearest the fuse never illuminates.

Thanks for taking the time to read my post :-)

Last edited by CaptainMAD; 04-04-2010 at 08:40 PM.
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  #2  
Old 04-05-2010, 01:45 AM
kkazem kkazem is offline
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Default Troubleshooting Help

Hi,
Since I don't have a schematic for your treadmill, I can only give you general hints and things to do. First and foremost, call the manufacturer and talk to the parts department first, and ask if they can email you a copy of the repair manual or at least the schematic and Bill of Materials, if they can't or won't, then call back and ask the repair department and make sure to talk to a technician--they are often sympathetic with technical people that want to fix their own unit. And, while you have them on the phone, tell them briefly what the problem is and what you've found with the 20V and the diode checks and ask them what they think it might be and if they've seen that problem before (they undoubtably have). If you don't get anywhere with that tack, then go back to the motor control ckt board. This is almost certainly a PWM motor control using either power BJT's, Power Mosfets, Power IGBT's, or a Power Module (the module thing is unlikely). These power devices nearly always fail shorted, and they are all 3-terminal devices. Caution!!! Do Not attempt to repair unless the unit has been unplugged for at least 10 minutes, and even then, be cautious--use your DVM to ensure that the DC power supply voltage is below 5 or 10 volts and of course, only work on it unplugged, not just turned off. There is likely a voltage doubler on the AC making up to 375 VDC for the PWM motor drive, even if no doubler ckt, then about 190 VDC. If it has UL approval, the high-voltage DC supply is supposed to have bleeder resistors to bleed the dc down to below about 50VDC (SELV-safety extra low voltage) after no more than 1 minute, but better safe than dead--always measure after letting it sit for 5 or 10 minutes after unplugging it. Then, check the power switches for the motor control. It will either be a half-bridge (2 power switches) or a full bridge (4 power switches) that likely operate at close to 20KHz to eliminate audible noise in the switching pwm motor controller. This ckt is exactly the same topology as a switching power supply using a full or 1/2 bridge topology, except that the switch load is a motor and not a high-frequency transformer, etc. Although some manufacturers get their semi's house marked to make it hard for anyone else to tell what the real p/n's are, this is not done much these days. If you can get the datasheet on the power switches, you will know if they are MOSFETS, IGBT's, or BJT's and then you may very well be able to identify blown power switches with your DMM using the ohms and/or diode scales, depending on the type of part.
Good luck,
Kamran Kazem
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  #3  
Old 04-05-2010, 09:25 AM
CaptainMAD CaptainMAD is offline
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Default

Thank you for your prompt and informative answer. I have incuded a link to a photo of the board, just in case anyone recogises it from another device and has had similar problems.

http://i212.photobucket.com/albums/c...z/DSCF1978.jpg

Last edited by CaptainMAD; 04-05-2010 at 09:37 AM.
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  #4  
Old 07-26-2010, 05:09 AM
jatinah jatinah is offline
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Default Did you ever figure out the motor control board?

Saw your post and wondered if you figured out your motor control board. I know this board, so let me know if you have questions. There is no voltage doubler on this board, and the 20vdc you read on the motor pins, is a dc bias voltage on the DC voltage rail. This rail goes up to 165vdc when the safety relay energizes. This relay will not activate if the kickback diode or driving FET are blown, which is usually the case.....
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Old 07-26-2010, 11:48 AM
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Without a schema it is impossible to tell you what to do exactly.

Post pictures of everything. Closeups of circuit boards from all sides and also of whatever labels the tread has.

This will help a alot.
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Old 08-01-2010, 04:56 AM
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JoeJester JoeJester is offline
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Quote:
i need mc60 board circuit diagram
You can certainly draw one from your existing PCB.
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Old 08-02-2010, 04:25 AM
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Quote:
Originally Posted by JoeJester View Post
You can certainly draw one from your existing PCB.
I second that
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Old 10-28-2010, 06:12 PM
gregmurphy0 gregmurphy0 is offline
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I have the exact same problem. The Scr also tested ok. If anybody found the problem please let me know. Thanks.
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Old 10-28-2010, 06:26 PM
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Quote:
Originally Posted by gregmurphy0 View Post
I have the exact same problem. The Scr also tested ok. If anybody found the problem please let me know. Thanks.
Let u know..just like tht ..huh!

Share something for a change...
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  #10  
Old 11-01-2010, 11:52 PM
jatinah jatinah is offline
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Wink Horizon SJED08011DG Motor Control Board

Hi Again.....this particular controller is prone to fail at the Switching FET and the Kickback Diode. Looking at the pic in a previous post, these would be the components standing up, to the rear right of the PCB. The FET would be an IRFP250 and the Diode is most likely the dreaded MOSPEC diode rated at 15A, which shorts, and immediately rips the FET. ;o)
You then also need to check 2 parallel schottky diodes, back-2-back, which are configured in parallel with the current limit resistor next to it. This was an older design of clamping the current sense line to avoid catastrophic failures, but the design was flawed elsewhere ;o)
You have to pull up one end of both diodes, schottky's will read about .160 on a digital meter, unlike a regular silicone diode which reads about .550-.650 on the same diode-scale on the DMM.
Those that would like advanced info on this controller can email me at <snip>

Last edited by beenthere; 11-11-2010 at 11:57 PM. Reason: Removed email to foil spambots and possibly phishing
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