Like New Nautilus Exercise Bike has Dead Panel

**budm** · 08-26-2018, 09:31 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

1) So the red power connector has 3 wires? RED/WHITE/BLACK red?
2) Is that the correct power supply? Did you verify the polarity requirement of the center pin?
3) Where does the power supply cord go to? I do not see which connector it fits into.
4) Pictures #6 looks like the terminal for the Black wire with white stripe is coming off the connector.

**Curious.George** · 08-26-2018, 11:41 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by vestaviascott

I got this bike really cheap in hopes I could bring it back to life. Its a Nautilus GX 2.7 Exercise bike. Cosmetically it looks like its never been used.

<grin> It probably HASN'T! Exercise bikes tend to fall out of favor pretty quickly with their owners...

However, the panel is dead and won't even light up when power is applied.
...
The power requirements are 9 volts 2 amps:

The power adapter (bought from Amazon. The bike came without a power adapter):

Interesting way to spell "Caution"!

First thing you'll notice is that the power adapter has *two* conductors -- the outer "sleeve" and the inner contact. The illustration on the adapter shows that the sleeve is "-" and the inner contact is "+". (Get this polarity wrong -- backwards -- and you'll likely toast whatever you plug it into!)

With your VOM/DMM on the ~20V DC scale, you should be able to verify something akin to +9V (undoubtedly HIGHER!) is present when you insert the positive DMM lead into the inner contact and hold the negative lead against the outer sleeve.

If you don't see voltage (and the correct polarity), your adapter is defective (unlikely given that it is "new"). Or, you aren't making good contact with one or both DMM leads.

If you see a negative voltage, then you may have the leads swapped at the DMM (red is positive, black negative).

The power connection that the adapter plugs into at the front bottom of the bike:

First question you should be asking yourself is: two conductors from power adapter but THREE wires on wiring harness! What's the third wire doing??

(It's unclear from your photos when the third wire comes into existence -- is it "here" or after this next photo?)

The power input harness at the front bottom of the bike:

The end of the harness that attaches to the panel console at the top of the bike:

Next question is how you magically went from *3* wires to *10*??!

Ans: there's something in the bowels of the bike that you've not yet seen!

You need to make a little diagram showing the two wire power adapter on one end of the page and the 10 wire connector on the other side of the page. Then, dig through the bike until you can see where those two wires morphed into those 10!

**vestaviascott** · 08-27-2018, 01:03 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by budm

1) So the red power connector has 3 wires? RED/WHITE/BLACK red?

Red, White, Black with white line

Originally posted by budm

2) Is that the correct power supply? Did you verify the polarity requirement of the center pin?

I ordered the adapter from amazon:

https://www.amazon.com/gp/product/B01598AE3A/

It was specified as a replacement for this specific bike. I did not verify the center pin polarity because i had/have no reference for what it should be. A service manual for this bike would be golden but I cannot locate one.

Originally posted by budm

3) Where does the power supply cord go to? I do not see which connector it fits into.

Below: Pic taken of harness assembly as it comes into bike from the barrel plug in pic above. The harness connects to the resistance motor and the speed sensor, then runs into the white wrapped cable that goes up to the panel console at the handlebars.

Originally posted by budm

4) Pictures #6 looks like the terminal for the Black wire with white stripe is coming off the connector.

That is correct, the black wire with white stripe (or white wire with black stripe, they are about equal in prominance) originates at the plugin harness at the bottom of the bike (from the first pic I posted in this reply)

**vestaviascott** · 08-27-2018, 01:16 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by Curious.George

With your VOM/DMM on the ~20V DC scale, you should be able to verify something akin to +9V (undoubtedly HIGHER!) is present when you insert the positive DMM lead into the inner contact and hold the negative lead against the outer sleeve.

**budm** · 08-27-2018, 01:19 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

So the power supply has + and - output = 2 wires but your red power connector has 3 wires so we need to find out why it has 3 wires. Need the pictures of that DC input jack to see how the 3 wires are connected to the DC input jack.

**vestaviascott** · 08-27-2018, 01:19 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by Curious.George

Next question is how you magically went from *3* wires to *10*??!

Ans: there's something in the bowels of the bike that you've not yet seen!

You need to make a little diagram showing the two wire power adapter on one end of the page and the 10 wire connector on the other side of the page. Then, dig through the bike until you can see where those two wires morphed into those 10!

Totally agree, which is why I went about trying to remove the side panels. However, the little hole around the crank is not large enough to take the panel off without taking the crank off. I've taken the cap off the crank and removed the bolt inside but I'm still noodling how the hell to get the crank off after that.

**vestaviascott** · 08-27-2018, 01:28 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Here's a better shot of what's going on inside the bike. The power harness hooks into the tension motor and then into the speed sensor.

There doesn't appear to be any other circuitry other than the tension motor so I believe the wire increase comes from an adapter harness in this loop. Still working to get the cover off so I can get at this harness.

**vinceroger69** · 08-27-2018, 01:31 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

something like this will remove it or a two legged puller
https://www.ebay.co.uk/itm/Bicycle-C...sAAOSw8FBbFfL9
different model slightly but shows wiring you cant see
https://www.youtube.com/watch?v=3BJzrbIy2RU

**vestaviascott** · 08-27-2018, 01:36 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Best I can tell, here's how we go from 3 wires to 10:

3 wires coming from adapter harness
5 wires coming from tension motor
2 wires coming from speed sensor

All of these are bundled and carried up to the console via the white loom.

**vestaviascott** · 08-27-2018, 01:40 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by budm

So the power supply has + and - output = 2 wires but your red power connector has 3 wires so we need to find out why it has 3 wires. Need the pictures of that DC input jack to see how the 3 wires are connected to the DC input jack.

This? Or something else?

**vestaviascott** · 08-27-2018, 01:45 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Here is a better shot showing the 3 wires coming from the adapter plug wire:

This is the adapter you see in the previous pic but a better angle to show the 3 wires. It connects to a connector that has the same 3 wires.

**vestaviascott** · 08-27-2018, 04:33 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

So, now that we know how the 3 input power wires turned into 10 (tension motor and speed sensor), is it possible to begin troubleshooting the control panel?

**vestaviascott** · 08-27-2018, 04:50 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by vinceroger69

different model slightly but shows wiring you cant see
https://www.youtube.com/watch?v=3BJzrbIy2RU

Awesome find. Here are some stills I grabbed to show the tension motor which is responsible for 5 of the 10 wires going into the control panel:

**Curious.George** · 08-28-2018, 02:44 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by vestaviascott

So, now that we know how the 3 input power wires turned into 10 (tension motor and speed sensor), is it possible to begin troubleshooting the control panel?

As I said, upthread -- MAKE A DRAWING. Or, do you expect each of use to try to "trace" wires from a dozen different snapshots to try to figure out "what goes where"?

There are TWO conductors on the power connector ("wall wart"). You haven't explained why anyone would WASTE a THIRD wire to attach to a two-wire connector.

If I see a "Blue" wire in ANY photo, can I assume that it is electrically connected to every other instance of a blue wire in ANY other photo? What about Red? Etc.

With the piece of equipment in front of you, you *could* troubleshoot it by running your fingers along a particular wire to see where it goes. Doing that from a bunch of photos is considerably harder -- the wire may not be completely visible, we may not understand the "view" we are being shown, etc.

Even if YOU can trace a single wire, you will find that making a drawing will save you the trouble (and possibility of making a mistake) of having to remember where each wire went. A drawing gives you The Big picture.

[You started this thread stating: "I'm new to electronics troubleshooting but I really want to learn the basics. I feel like its a skill that I really want to invest time to learn." My comments are intended to get you thinking in a more systematic way -- so you will learn to SEE where you need to look for problems.]

**vestaviascott** · 08-28-2018, 02:55 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Sounds good. I'll make a drawing. Thanks for the help.

**budm** · 08-28-2018, 04:32 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

As you can see in your post # 1 & 11, you show someone else picture (FRP?) of the DC input jack which we cannot see how 3 wires are soldered to the DC input jack, you need to show the pictures of your unit.

**vestaviascott** · 08-28-2018, 07:27 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Sorry guys, been a crazy day at work. Here are some pics of that barrel connector and I'll also draw a wiring schematic from here all the way up to the console:

**Curious.George** · 08-28-2018, 10:03 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Originally posted by vestaviascott

Sorry guys, been a crazy day at work. Here are some pics of that barrel connector and I'll also draw a wiring schematic from here all the way up to the console:

Interesting. This suggests there may be a switch in the connector (though I can't imagine why -- there are no batteries in the unit, are there?) I.e., the designers decided that there is a need for the circuit to "know" when the wall wart is MECHANICALLY plugged in -- despite the fact that voltage would only be present to the circuit IF it was plugged in!

WITH THE HARNESS UNPLUGGED (i.e., with the "pink" connector's contacts accessible), plug the wall wart into the jack (and into AC). Now, carefully (so you don't accidentally short your probes -- and the power supply! -- together) probe between each pair of wires (there are three pairs: 1+2, 2+3 and 1+3).

You should see the wall wart's output voltage (~9.2V) on at least one of the pairs. These represent the conductors that are directly connected to the center contact and outer sleeve of the wall wart's plug. If the display reads (+) 9.2V, then whichever wire is connected to the positive input of the DMM corresponds to the center contact of the plug. The other DMM lead is on the sleeve of the plug. If the display is -9.2V, then the opposite is true (i.e., the positive lead of the DMM is on the sleeve of the connector)

Make a note of this in your drawing so you know where "ground" and "power" come into the circuit.

Now, with your DMM on "ohms" scale, see if you have continuity between either of the "other" pairs.

For example, if 1+3 showed you the 9.2V (which may appear as -9.2 depending on how your leads happen to be positioned on the contacts) and 2+3 showed "nothing" as did 1+2, then check for continuity between 2+3 and also between 1+2.

Note that if you saw voltage on any of these other pairs, don't bother checking for continuity.

Then, unplug the wall wart -- from the AC and from the wire harness -- and probe all three pairs for continuity.

If there is a mechanical switch in the connector, the act of inserting the wall wart's plug will open (or close) it. The above is trying to identify the presence of a switch and its action.

**budm** · 08-28-2018, 10:17 PM

Re: Like New Nautilus Exercise Bike has Dead Panel

Check the resistance between center pin of the DC input jack and the red wire on the red connector: I expect it to show <1 Ohms,.
Check the resistance of the terminal of the red connector that is connected to black wire against the terminal that the white wire is connected to: I expect it to show <1 Ohm.
Notes: AC adapter is not connected to the DC input jack during this test.
BTW, there is strange warning about the AC adapter.

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Like New Nautilus Exercise Bike has Dead Panel

Like New Nautilus Exercise Bike has Dead Panel

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