Help with Motor Control Board - ProForm treadmill - Page 13

**selldoor** · 01-19-2015, 12:44 PM

Watching videos is fine but you need to do some as well?

**Crrose** · 01-19-2015, 04:14 PM

Need to get some old circuit boards to mess with. Checking craigslist for free electronics.

**keeney123** · 01-24-2015, 11:48 PM

How the soldering experiment coming along?

**Crrose** · 01-26-2015, 11:43 AM

Very tedious and difficult. Small resistors and caps are ok since it's one leg at a time but doing SMDs very difficult. Looking for a cheap hot air gun or how to make one. Still waiting for parts to arrive, apparently they are shipped from china. Got the small TC1410 from Mouser but couldn't find the W33n20 anywhere else.

**keeney123** · 01-27-2015, 10:02 PM

To desolder the SMD could you not just cut the legs of the bad SMD and desolder them one at a time? They also make a low temp solder that you could add the the solder on the SMD and that will lower the melting point of the present solder on the SMD so you can heat all the pins of the SMD and before they cool down below the lower melting point you would be able to remove the SMD and then go over the pads with solder wick to clean them up.
To solder the SMD one has to first tack it down on two opposing corners then it is also, good to use a hoof tip that has a little reservoir for solder. You would put flux down and put a little solder in the tip of the iron and then drag the iron on the outside of the pins making contact with the pad and pin at the same time and only adding a little solder if needed. You would start at the opposite side of the pins you tacked down.

**Crrose** · 01-31-2015, 02:54 PM

Just and update on status, still waiting for parts from china.

**Crrose** · 02-04-2015, 12:42 PM

Well I replaced the TC1410 chip and the W33N20 mosfet, turned treadmill on and motor no longer started on its own at high speed which was good news, but, it acted like it was prior to me shorting out the mosfet. After maybe a minute the W33N20 popped and spit out some smoke underneath the board and shorted out.

**Agent24** · 02-04-2015, 02:59 PM

Bummer. Sounds like something else is still wrong causing the MOSFET to blow.

**budm** · 02-04-2015, 03:20 PM

Quote:

Originally Posted by Crrose

Well I replaced the TC1410 chip and the W33N20 mosfet, turned treadmill on and motor no longer started on its own at high speed which was good news, but, it acted like it was prior to me shorting out the mosfet. After maybe a minute the W33N20 popped and spit out some smoke underneath the board and shorted out.

The motor is connected in series with the MOSFET, if it shorted out the motor would have been running full speed (MOSFET is basically connected in series with the motor).
Are you sure everything is connected properly, and the soldering works are good?

**Crrose** · 02-04-2015, 03:49 PM

I bought extra so will try to redo it one more time and see what happens. Bought 3 TC chips but for some reason only 2 of the other mosfets.

**budm** · 02-04-2015, 04:04 PM

Let us see the pictures after the parts installation first.

**goontron** · 02-04-2015, 04:04 PM

by any chance to the braking resistors get hot when its running? the relay might not be dropping out.

**Crrose** · 02-04-2015, 05:06 PM

Quote:

Originally Posted by goontron

by any chance to the braking resistors get hot when its running? the relay might not be dropping out.

What are the braking resistors?

And yes I will post pictures of board with new pieces on.

80wa7113 · 01-26-2018, 12:23 PM

Hi Crrose,

I realize this thread is almost a couple of years old, but, did you ever get this issue resolved? I found your thread while doing research for the exact same problem I'm having with yet another failed MC70 motor control board...no motor start with a burned board at DZ4A/B.

Regards,

Dave

80wa7113 · 01-31-2018, 06:41 PM

Well, there was just going to be NO fixing this board. I replaced my fried zener diode (DZ4) and also replaced the other DZ4 as well as DZ2 and the accompanying resistor with no luck. Without a schematic it is next to impossible to properly diagnose the failing component. Searches of the internet only came up with guys who repair the boards...BUT I also found a company called Gemini Controls out of Wisc. who makes the latest generation of PWM's to fix these DOA treadmills. Their NEW board was $149.00 - about $10 more than having this one repaired. I opted for new with a thin price difference like that.

Installed the new board and we're up and running again!

Old board heading to the landfill....

4umfreak · 01-13-2020, 02:52 PM

Hey all, Again this old thread was helpful for me getting my MC70 treadmill motor control board running.

For future individuals looking to repair their boards, here's what I replaced:

1x 24v 5W zener diode
1x 15v 1.3W zener diode
1x 1N4007 rectifier diode (general purpose)
1x 1K 10W ceramic resistor

I had to bridge / repair the fried traces on *both* sides of the 24v zener diode. I simply used leads from a spare 1N4007 that was handy.

The zener diodes were easy to spot & the resistor was replaced as a preventative measure. Mine was showing evidence of overheating with a white-ish color.

The 1N4007 is the one at the end of the 1K resistor, where the AC connection is made. In my case, it looked ok but tested bad and was something I had on hand, so replacing it was an easy choice. Without replacing this diode - the board appeared to be completely dead.

After replacing the above components, I cleaned off the old thermal paste and installed a thin coating of new paste.

I hope someone finds this information helpful. My repair cost less than $20 CAD, plus shipping.

Cheers,
-Mark

ken1415 · 11-24-2020, 02:32 PM

Quote:

Originally Posted by 4umfreak

Hey all, Again this old thread was helpful for me getting my MC70 treadmill motor control board running.

For future individuals looking to repair their boards, here's what I replaced:

1x 24v 5W zener diode
1x 15v 1.3W zener diode
1x 1N4007 rectifier diode (general purpose)
1x 1K 10W ceramic resistor

I had to bridge / repair the fried traces on *both* sides of the 24v zener diode. I simply used leads from a spare 1N4007 that was handy.

The zener diodes were easy to spot & the resistor was replaced as a preventative measure. Mine was showing evidence of overheating with a white-ish color.

The 1N4007 is the one at the end of the 1K resistor, where the AC connection is made. In my case, it looked ok but tested bad and was something I had on hand, so replacing it was an easy choice. Without replacing this diode - the board appeared to be completely dead.

After replacing the above components, I cleaned off the old thermal paste and installed a thin coating of new paste.

I hope someone finds this information helpful. My repair cost less than $20 CAD, plus shipping.

Cheers,
-Mark

Mark - can you give the locations of the components you replaced?

1x 24v 5W zener diode
1x 15v 1.3W zener diode
1x 1N4007 rectifier diode (general purpose)
1x 1K 10W ceramic resistor

01-19-2015, 12:44 PM	#241
selldoor Slow Learner Join Date: Dec 2010 City & State: Lancashire UK Posts: 7,853	Re: Help with Motor Control Board Watching videos is fine but you need to do some as well?

01-19-2015, 04:14 PM	#242
Crrose Senior Member Join Date: Dec 2013 City & State: Brea ca My Country: Usa I'm a: Knowledge Seeker Posts: 149	Re: Help with Motor Control Board Need to get some old circuit boards to mess with. Checking craigslist for free electronics.

01-24-2015, 11:48 PM	#243
keeney123 Lauren Join Date: Sep 2014 City & State: North Adams MA My Country: United States Line Voltage: 120VAC, 60Hz I'm a: Knowledge Seeker Posts: 2,086	Re: Help with Motor Control Board How the soldering experiment coming along?

01-26-2015, 11:43 AM	#244
Crrose Senior Member Join Date: Dec 2013 City & State: Brea ca My Country: Usa I'm a: Knowledge Seeker Posts: 149	Re: Help with Motor Control Board Very tedious and difficult. Small resistors and caps are ok since it's one leg at a time but doing SMDs very difficult. Looking for a cheap hot air gun or how to make one. Still waiting for parts to arrive, apparently they are shipped from china. Got the small TC1410 from Mouser but couldn't find the W33n20 anywhere else.

01-27-2015, 10:02 PM	#245
keeney123 Lauren Join Date: Sep 2014 City & State: North Adams MA My Country: United States Line Voltage: 120VAC, 60Hz I'm a: Knowledge Seeker Posts: 2,086	Re: Help with Motor Control Board To desolder the SMD could you not just cut the legs of the bad SMD and desolder them one at a time? They also make a low temp solder that you could add the the solder on the SMD and that will lower the melting point of the present solder on the SMD so you can heat all the pins of the SMD and before they cool down below the lower melting point you would be able to remove the SMD and then go over the pads with solder wick to clean them up. To solder the SMD one has to first tack it down on two opposing corners then it is also, good to use a hoof tip that has a little reservoir for solder. You would put flux down and put a little solder in the tip of the iron and then drag the iron on the outside of the pins making contact with the pad and pin at the same time and only adding a little solder if needed. You would start at the opposite side of the pins you tacked down. Last edited by keeney123; 01-27-2015 at 10:03 PM.. Reason: correction

01-31-2015, 02:54 PM	#246
Crrose Senior Member Join Date: Dec 2013 City & State: Brea ca My Country: Usa I'm a: Knowledge Seeker Posts: 149	Re: Help with Motor Control Board Just and update on status, still waiting for parts from china.

02-04-2015, 12:42 PM	#247
Crrose Senior Member Join Date: Dec 2013 City & State: Brea ca My Country: Usa I'm a: Knowledge Seeker Posts: 149	Re: Help with Motor Control Board Well I replaced the TC1410 chip and the W33N20 mosfet, turned treadmill on and motor no longer started on its own at high speed which was good news, but, it acted like it was prior to me shorting out the mosfet. After maybe a minute the W33N20 popped and spit out some smoke underneath the board and shorted out.

02-04-2015, 02:59 PM	#248
Agent24 I see dead caps Join Date: Oct 2007 City & State: Hiding inside a plated-through hole My Country: New Zealand Line Voltage: 230VAC 50Hz I'm a: Hobbyist Tech Posts: 4,658	Re: Help with Motor Control Board Bummer. Sounds like something else is still wrong causing the MOSFET to blow. __________________ "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous" -David VanHorn

02-04-2015, 03:49 PM	#250
Crrose Senior Member Join Date: Dec 2013 City & State: Brea ca My Country: Usa I'm a: Knowledge Seeker Posts: 149	Re: Help with Motor Control Board I bought extra so will try to redo it one more time and see what happens. Bought 3 TC chips but for some reason only 2 of the other mosfets.

02-04-2015, 04:04 PM	#251
budm Badcaps Veteran Join Date: Feb 2010 City & State: S.F. Bay area My Country: USA Line Voltage: 120V 60Hz I'm a: Knowledge Seeker Posts: 39,051	Re: Help with Motor Control Board Let us see the pictures after the parts installation first.

02-04-2015, 04:04 PM	#252
goontron 5000! Join Date: Dec 2011 City & State: South Greeley, Wyoming My Country: US Line Voltage: 13.9kv HT service and some 240v center tap oddity. I'm a: Professional Tech Posts: 4,029	Re: Help with Motor Control Board by any chance to the braking resistors get hot when its running? the relay might not be dropping out. __________________ Things I've fixed: anything from semis to crappy Chinese $2 radios, and now an IoT Dildo.... "Dude, this is Wyoming, i hopped on and sent 'er. No fucking around." -- Me Excuse me while i do something dangerous You must have a sad, sad boring life if you hate on people harmlessly enjoying life with an animal costume. Sometimes you need to break shit to fix it.... Thats why my lawnmower doesn't have a deadman switch or engine brake anymore Tomorrow Is Nearly Yesterday And Everyday Is Stupid!

01-26-2018, 12:23 PM	#254
80wa7113 New Member Join Date: Jan 2018 City & State: Indianapolis, IN My Country: USA I'm a: Knowledge Seeker Posts: 2	Re: Help with Motor Control Board Hi Crrose, I realize this thread is almost a couple of years old, but, did you ever get this issue resolved? I found your thread while doing research for the exact same problem I'm having with yet another failed MC70 motor control board...no motor start with a burned board at DZ4A/B. Regards, Dave

01-31-2018, 06:41 PM	#255
80wa7113 New Member Join Date: Jan 2018 City & State: Indianapolis, IN My Country: USA I'm a: Knowledge Seeker Posts: 2	Re: Help with Motor Control Board Well, there was just going to be NO fixing this board. I replaced my fried zener diode (DZ4) and also replaced the other DZ4 as well as DZ2 and the accompanying resistor with no luck. Without a schematic it is next to impossible to properly diagnose the failing component. Searches of the internet only came up with guys who repair the boards...BUT I also found a company called Gemini Controls out of Wisc. who makes the latest generation of PWM's to fix these DOA treadmills. Their NEW board was $149.00 - about $10 more than having this one repaired. I opted for new with a thin price difference like that. Installed the new board and we're up and running again! Old board heading to the landfill....

01-13-2020, 02:52 PM	#256
4umfreak New Member Join Date: Jan 2020 City & State: Victoria, BC My Country: Canada I'm a: Knowledge Seeker Posts: 1	Re: Help with Motor Control Board Hey all, Again this old thread was helpful for me getting my MC70 treadmill motor control board running. For future individuals looking to repair their boards, here's what I replaced: 1x 24v 5W zener diode 1x 15v 1.3W zener diode 1x 1N4007 rectifier diode (general purpose) 1x 1K 10W ceramic resistor I had to bridge / repair the fried traces on both sides of the 24v zener diode. I simply used leads from a spare 1N4007 that was handy. The zener diodes were easy to spot & the resistor was replaced as a preventative measure. Mine was showing evidence of overheating with a white-ish color. The 1N4007 is the one at the end of the 1K resistor, where the AC connection is made. In my case, it looked ok but tested bad and was something I had on hand, so replacing it was an easy choice. Without replacing this diode - the board appeared to be completely dead. After replacing the above components, I cleaned off the old thermal paste and installed a thin coating of new paste. I hope someone finds this information helpful. My repair cost less than $20 CAD, plus shipping. Cheers, -Mark

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