Nordic Track Elliptical Trainer troubleshooting

[@eighties8]

Amazing tutorial. I buy and sell preowned fitness machines and by far, the #1 issue I see is faulty console resistance circuits. Until now, I had no way to troubleshoot or fix them. In only about 20% of the cases, the 6v servo motor is the cause, those are super easy fixes. However, the majority are console issues. As a result, I have a 10x30 storage facility full of otherwise perfect ellipticals and exercise bikes that all have faulty resistance circuits. Now I can use your video tutorial to try to fix them! Thanks!

[@eighties8]

Perhaps since this circuit is so popular, its used on every exercise bike and elliptical currently made, they have combined the bridge circuit into a single IC chip? If so, perhaps we can identify that chip, its manufacturer and we can simply replace it whenever we have issues like this regardless of the cause.

[@eighties8]

After some further research that is indeed what I'm finding. The H bridge circuit described here is now encapsulated in a driver IC chip. For example, BD6210 chip is used on many machines to perform this function in a single chip vs the separated H bridge circuit component setup in the video.

[@springpan]

This was great! Excellent circuit analysis, and I really liked your explanation of the motor servo bridge circuit. I also appreciated your tutorial on the pulley shaft differences. I just bought a used Nordic Track elliptical for $70 used off of CL and tested the tension controller first thing. Now I need to figure out how to get this beast into my spare bedroom! Thanks, I will watch your other videos.

[@enginord]

hi Springpan. I'm glad you like the video. Stay tuned. More to come.

[@bftfcfua2946]

I got the same problem (the PWR light is off on the lower control panel) , and I fix a lot of stuff, but replacing the transistors is above my skill level so I added 2 wires on the DC motor, and can not adjust the tension ahead of time with a 9 voly battery, works fine for now but

[@joeneil5136]

Thanks for doing this I ordered the transistors. Should be here in a week!

[@eighties8]

Hi Joel, can you share some additional info about your issue? Which machine? Symptoms, etc...

[@steadyeddie7453]

It's refreshing to see people still test circuit boards down to the component level. Well done. As for the shaft issue, I think you may be missing something. The wear marks on the shaft are because the inner races of the bearings are turning on the shaft, thus wearing the shaft. The inner races should be press fit on the shaft, so the inner races and the shaft effectively dont turn. Then the bearings work as designed. And you don't need the hardness of a linear shaft as a replacement. I like to use drill rod. Its a good compromise and more than adequate for this application. Thanks for the video.

[@enginord]

Hi Eddie. Thanks, glad you liked the video. Interesting insight for the drill rod. I have not thought of that. Looks like oversized O1 drill rod is readily available. I'll keep that in my mind. All the other options I looked into, were undersized.

[@steadyeddie7453]

@@enginord You can get drill rod in diameters to match most any standard bearing ID. But the main thing is that the shaft should never show wear where the bearing rides. The inner race of the bearing should be a press fit on the shaft. And the outer race of the bearing should be a press fit into the steel plate (looking at your video at 20:00). If the outer race spins it too will wear out the plate it sits in. I like to use a little retaining compound on the races. With a press fit and a little retaining compound, you should never have to deal with the shaft wear for the life of the machine.

[@Deus1919]

Great video! Very instructive!

[@PJACQ123]

Great video bought the parts off Amazon for six dollars for 100 fix mine good job

[@enginord]

Glad it helped. Subscribe if you haven’t done so for more fascinating content!

[@ericlyons11]

Great video. I'm thinking mine has some bad transistors as well but I was hoping for a little more help. I get a +5 volts at the motor in one direction but when I change the resistance in the other direction I get a flashing voltage all over the place, I'm thinking a short circuit. I'm trying to test the transistors, I assume I have to test them while the elliptical is plugged in? I'm just a little afraid that I will some how touch the wrong places and really mess this thing up? Thanks

[@ericlyons11]

I finally figured out how to with my multimeter. So I didn't have to test with the power plugged in. It seems the 2 transistors in the middle are bad.

[@enginord]

@@ericlyons11 glad you found the faulty ones. yeah. test the transistors when the circuit is NOT under power.

[@eighties8]

Do you guys have the same elliptical? I have several makes and models of exercise bikes and ellipticals that have resistance controller issues, but they don't all appear to have this same 4 transistor "H Bridge" configuration, that I can tell, but the resistance motors on all machines are exactly the same, just like this one. All 6v and look the same. Do the controllers employ different techniques vs the 4 transistor "H bridge" to control resistance?

[@joecualquiera]

I'd like your opinion regarding why the transistor went bad? Any ideas? Voltage regulating ? Transistor quality? Heat? Any advice on how to prevent this from happening? Meanwhile I have placed a voltage regulator and uninterruptible power system just to stay on the safe side and protect my machine.

[@enginord]

Hi Alberto. I'm really not sure why that transistor blew up. I have several guesses, but these are just guesses. One could be the motor's inductance, maybe it's designed for a different motor, but due to supply chain issues the buyers replaced the motor without engineering approval. the other guess is the long (1.5 meter) cables connecting the motor & the electronics act like an antenna. There could be stray currents induced in that wire. It can also be bad batch of transistors. those are my guesses. If you read the comments you can see this is a typical problem for this machine. there is no built in protection for those transistors.

[@joecualquiera]

@@enginord thank you very much. I appreciate your time and help. And of course we got to thank you for the effort to document and explain the solution to this problem. Keep up the good work 👍🏻👍🏻

[@ericlyons11]

This video was exactly my problem,. I was able to replace 2 transistors and it fixed my problem. Thanks. I might not have but the it back together 100% because now I get a hum sound from the speaker and when I touch the audio adapter wire hanging out, the speaker hum cracks more. Can you please suggest what to look for or how to fix?

[@enginord]

hi Eric. I'm glad you were able to make it work. for the audio problem check the connectors, and the shielding cables for the 3.5mm jack. just in general make sure there is no foreign objects on the pcb.

[@ericlyons11]

@@enginord thanks, any chance you remember where the 2 green ground wires attach?

[@enginord]

@@ericlyons11 Sorry. Can't remember that.

[@wookievr641]

Have you ran into NordicTrack Elliptical 7.0 tension motor constantly rotating to tighten tension after plugging in the machine to power? Changing level settings does not change anything. Only if i go into settings will the tensioner stop. The old motor stripped internally and I ordered new one but it skipped twice so Im not sure if its damaged or not. Is there a hard stop on the gear box that the travel range should not be exceeded?

[@enginord]

the motor has a potentiometer connected to it. if the initial setting is not right it might not work. you need to make sure you assemble the lever arm/gear to the motor in the same way. did you take pictures of the assembly before you disassembled the old stripped motor? Also. why did the gears in the motor strip? Are all the linkages, shafts rotate freely?

[@wookievr641]

@@enginord What started it all was that there was constant clicking that i found to be coming from the motor. Tension motor kept on tightening to the point it stripped internals. Figured I install new motor and new one got so tight before I unplugged the machine from outlet that it skipped twice. I can only see the motor turning to tighten the cable. Its operating erratically.

[@enginord]

@@wookievr641 well. if the motor is tightening that's good. that means the motor circuit is operating at least in one direction. Now the controller is telling the motor to tighten, cause it wants to go to a set point, which is defined by the potentiometer. If the wires on the pot are not connected correctly that can cause this behavior. disconnect the motor mechanically, but leave it attached electrically. salvage the pot from the old tension motor. hook up the old pot to the circuit. if you turn the machine on the electronics should command the motor to a certain position. if you manually turn the pot the motor should stop. lmk if you get to this point.

[@wookievr641]

@@enginord I will do as directed in coming days. Please standby.

[@wookievr641]

@@enginord Stripped the OE potentiometer and motor. L1 & L3 steady 4.790 K ohms. L1 & L2 range between full travel is 3.0 ohms to 4.792 K ohms. L2 & L3 is 3.2 ohms to 4.792 k ohms. No change in direction of motor rotation when rotating potentiometer and no reaction change in behavior of motor when adjusting potentiometer. When selecting different resistance setting buttons on the control counsel the motor will always spin in the same direction (it appears) and after 10-20 seconds it stops spinning. My interpretation of the findings is that control head is not receiving potentiometer resistance reading or the control head failed. Let me know what your thoughts are. I would think the next step is to check if the connecter is fully seated in the control head for wires coming from the potentiometer. Thank you again.

[@21221010258660]

Do you have any suggestions on when the circuit board is not supplying any voltage to the motor? the circuit boards lcd screen blocks the back so i cant trace where power comes from

[@enginord]

I assume the circuit board comes alive on your machine. that means it'll get power. the motor is only powered when a button is pressed. either up or down. you can measure that on the motor leads. I'm afraid you'll need to remove the whole board to see the traces.

[@doctorpete1]

I'm gonna call for a repairman!

[@dad1648]

This video is awesome. I was able to troubleshoot the problem down to the potentiometer on the resistance motor. Could you share how you removed and replaced the potentiometer? Did you need to disassemble to the plastic motor housing?

[@enginord]

yeah. unfortunately the only way t get the pot out is to disassemble the tension motor

[@ferysery]

hi. do u have any idea if the same retention motor mechanism used in NORDICTRACK AUDIOSTRIDER CX650 ?

[@enginord]

google says it's the same. I have not taken apart a NORDICTRACK AUDIOSTRIDER CX650 yet.

[@ferysery]

@@enginord if retention doesn't change, which part is the cause, motor or controller logic board panel?

[@enginord]

@@ferysery If the resistance does not change it can be the motor or the controller. Disconnect the motor, and apply voltage to the terminals, see if it runs left or right. then you can test the electronics if there is a voltage when the buttons are pressed. This will require a separate potentiometer though.

[@ferysery]

@@enginord hi again. i'm confused, the potentiometer and transistor both were faulty in ur case?

[@ferysery]

and how can i take apart the motor itself to replace the potentio with a brand new 5kOhms potentio?

[@yzmoto80]

Wait a minute ! You mean to tell me we have been overpaying for electronics ? 🤔