Like New Nautilus Exercise Bike has Dead Panel

[redwire]

Re: Like New Nautilus Exercise Bike has Dead Panel

That DC jack does have a switch. Pin 1 center pin (+red?), pin 2 barrel (-black/white stripe?), pin 3 switched barrel (mystery beige?).
The mating connector seems to only have two wires (gray, red with white stripe)?

Best to check it with a continuity test.
Most important is knowing the barrel polarity, if it is (-) or (+) on the treadmill.

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

Interesting Budm. That may be what happened to the damn thing. I haven't been able to get away from work for a few days. Hoping to have a chance to run these tests this weekend and get a drawing up.

At this point, I've written off this bike for any profit, HOWEVER, the insights and knowledge I'm gaining from your help will be very helpful in the future as I continue to take in cheap/free failed electronics and try to bring them back to life.

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

OK, finally had time to pull the crank, remove the side skirt and undo that cable bundle to trace the wires. Here's a couple of illustrations of the wire traces:

The wires are numbered sequentially in the order they appear in the wire harness in the 2nd pic below from right to left (there are 11 wires going into the harness, -W indicates a white lined wire):



From right to left, you can see there are 10 wires coming into the harness, 3a and 3b are the two gray wires that are spliced in the harness as you can see from the 3rd pic below:



The 3 wire is a splice of the two gray wires are fed into the harness from the power adapter harness and the speed sensor:



Finally, here is where the harness wires attach to the main board in the same order as the harness in pic 2 above:

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

Saturday finally here! So, I've finally got some time to work on this bike to try to figure out what's wrong with it.

First thing I would like to determine is if the board is getting power. To do that, I'm first going to measure the voltage of the red wire (#2) at the top console harness. I believe I should expect from 5-9 volts if everything downstream has proper continuity.

So, for the test, on the DMM, black lead to ground wire (#5) and red lead to red wire (#2), and I should get a voltage reading when the power adapter is plugged in. All good to start?

Once that test is complete, and assuming I get expected voltage, should I just pull this board and measure from the solder joints on this other side of these wires?

[Curious.George]

Re: Like New Nautilus Exercise Bike has Dead Panel

First thing I would like to determine is if the board is getting power. To do that, I'm first going to measure the voltage of the red wire (#2) at the top console harness. I believe I should expect from 5-9 volts if everything downstream has proper continuity.

Adopt some convention for referencing signals, pin numbers, connectors, etc. E.g., there are several "#2" pins -- the "10 pin red connector" appears to be the reference frame for your choice of "#2". But, there are other places where you may, eventually, be referencing (connector) pin numbers.

E.g., HD5 and HD6 each have NOTHING in the pin #2 position -- and HD1 has nothing in ANY position!

So, for the test, on the DMM, black lead to ground wire (#5) and red lead to red wire (#2), and I should get a voltage reading when the power adapter is plugged in. All good to start?

Yes, just be careful not to let the probe slip off and potentially short out "something".

As there is nothing (electrically) attached to the red wire (isn't it Red w/white tracer?), there is nothing drawing current from the power adapter. So, there will be no voltage drop along the length of the cable. What you saw AT the adapter should also be present "exactly" at the red connector (assuming you are probing it before connecting to the circuit board).

Once you mate the connector to the PCB, there will be some load on the power supply so you might see a TINY voltage drop at the circuit board end of the wire. This is because wire has resistance and, therefore, current flowing through it (to power the circuit board) causes a potential to be developed across it. "IR loss" (I=current, R=resistance, I*R=volts)

One of the first things you should do is verify the connection of the "ground wire" to the "large expanses of foil" (e.g., that cross-hatched area and anything electrically tied to it) on the circuit board. This will give you a variety of other places where you can make a connection to "ground" (convenience).

Once that test is complete, and assuming I get expected voltage, should I just pull this board and measure from the solder joints on this other side of these wires?

Visually trace the power signal as it transitions ONTO the circuit board. It will be a large-ish trace so relatively easy to follow. See where it goes. Pay particular attention to any devices that it appears to pass THROUGH (i.e., places where the only way for power to continue onto the board is THROUGH that device). Probe the "far side" of those device(s) to verify that power is, in fact, passing through. If not, you need to understand if the device/component has failed (e.g., fuse) and is interfering with power being available for the board or if the device is supposed to intentionally interrupt the flow (e.g., a device used as a "switch"). In the latter case, you'd need to figure out how to "turn on" that switch. Or, if it is there to somehow condition the power (e.g., a voltage regulator).

Goal, here, is to identify the OBVIOUS places where power should flow and verify that it does, in fact, do that.

[budm]

Re: Like New Nautilus Exercise Bike has Dead Panel

Can I see good clear straight shot of the console board?

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

Can I see good clear straight shot of the console board?

[budm]

Re: Like New Nautilus Exercise Bike has Dead Panel

Too blurry to me to read anything on the board, see it for your self what you can see in that picture.
I am trying to locate Voltage regulator IC's and some Voltage test points on that board.
I think I can see one 3-pin regulator.

[Curious.George]

Re: Like New Nautilus Exercise Bike has Dead Panel

I am trying to locate Voltage regulator IC's and some Voltage test points on that board.
I think I can see one 3-pin regulator.

Photo in post #24. D2 for reversed power protection, C14 on input and C15/C16 on output. (I can't see designator for the actual regulator).

My directions to OP would have him stumble on it within an inch of the wiring harness meeting the PCB as he traced foils...

[Curious.George]

Re: Like New Nautilus Exercise Bike has Dead Panel

That DC jack does have a switch. Pin 1 center pin (+red?), pin 2 barrel (-black/white stripe?), pin 3 switched barrel (mystery beige?).

Yes, but what likely role would a switch THERE serve in such a device? (Goal is to have OP think about why "it" would care about whether the power adapter was mechanically attached -- or not!)

[budm]

Re: Like New Nautilus Exercise Bike has Dead Panel

Pictures are too poor, there has to be regulator some where on that main board.

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

Pictures are too poor, there has to be regulator some where on that main board.

I'm taking these with iphone in HDR mode. I'll try again this morning with a lens over the phone to see if that helps. I will also take 4 zoomed quadrant shots of the main board. Coming up!

Really appreciate the help.

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

Top Left:



Top Right:


Bottom Right:


Bottom Left:

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

A high resolution stitched together copy of the 4 pics above:

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

Here's an ultra high res shot I took from my wife's iphone 7. THIS IS THE MONEY SHOT!

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

That DC jack does have a switch. Pin 1 center pin (+red?), pin 2 barrel (-black/white stripe?), pin 3 switched barrel (mystery beige?).
The mating connector seems to only have two wires (gray, red with white stripe)?

What you are calling "mystery beige", is actually gray in person. The mating connector does in fact have 3 wires, red, black with white stripe and solid gray (aka "mystery beige").

Here's where those 2 gray wires are spliced together just below the upper harness connector:



And here's the source of those two gray wires, one comes from the barrel connector power harness (3-Gray) and one comes from the speed sensor (3b-Gray):

[budm]

Re: Like New Nautilus Exercise Bike has Dead Panel

Here's an ultra high res shot I took from my wife's iphone 7. THIS IS THE MONEY SHOT!

That is better!
I see 3 regulator IC's RG1, RG2, RGA1, please get the P/N as printed on them, then check the DCV on all 3 pins against GND (you can use HD2 pin 1 empty connector pad for GND ref. point).

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

Awesome. Here are the P/N's:

RG1 = 3940M3 501434L

RG2 = GH16D 4266J2

RGA1 = 3940M3 501434L

[vestaviascott]

Re: Like New Nautilus Exercise Bike has Dead Panel

...then check the DCV on all 3 pins against GND (you can use HD2 pin 1 empty connector pad for GND ref. point).

Are these the right test lead placements?

[CapLeaker]

Re: Like New Nautilus Exercise Bike has Dead Panel

yes. Basically there are different voltage rails for different IC's to work. So, you got some thing like: 5V, 3.3V, 2.5V and 1.8V.
1st pin is power input, 2nd pin is GND or ADJ and the 3rd pin is power output.