Sole F80 Treadmill Repair - E7 Error (2016)

[sc122524]

I'm attempting to repair an older treadmill that I received as a gift. When trying to start the treadmill, it is able to power up successfully. But when pressing the start button, it starts counting down from 3 to 0, and it seems like it ever so slightly starts to try the motor before erroring out with an E7 error (Input power anomaly). I'm able to also run the calibration where it starts the motor for a brief second before shutting it off again, and reinitializes the LCD display, moves the incline motor back to its base, and then goes back to normal. (Still has the same startup error though).

I've tried testing the various circuits on the board, and from what I can tell, the components appear to be within their normal range. I believe that the yellowish stuff that is near some of the components is board glue, but I'm not 100% certain of that. The stuff itself appears to be solid. I have no idea how long the treadmill has been in this state though, as I just received it recently. I'm fairly handy with electronics, so any other components that could be tested to determine if they are faulty I could probably do. The new controller board is $250, so if its a 10 cent capacitor, I'd like to start with that approach as opposed to replacing everything for a cheap component.

I've checked as many components as I can reasonably get to, specifically starting with the MOSFETs that drive the motor.  My assumption was that it was either having trouble switching those own, or else the capacitors are not charging properly to supply enough power when first starting up the treadmill.  I've done the following troubleshooting steps:

1. Connected the motor directly to a power supply to run it (it runs)
2. Checked the RPM cable for the motor when it turns to see if it registers periodically (it does)
3. Tested the incline motor (it goes up and down)
4. I purchased another motor controller (though I think its slightly the wrong one) and it gets an E5 error.
5. Visually inspected the circuit board for any burnt parts / connections (didn't see any)

Unfortunately, I don't have any schematic of the system directly, but I do have a few of the service manual docs that have some advanced troubleshooting steps.  Those didn't seem to really help in this particular situation.

[m k]

Input power anomaly can be from its self or guided to be so.

Can you measure the input voltage of that moment?

Guided anomaly would be overcurrent or stuff like that.

[Poroit]

G'day sc122524,

The "Yellow stuff" will be there to mechanically protect the components from vibration.

Is it a Switch Mode power supply?

Focus on determining the power supply DC voltages that should be available. eg +5V, -5V, +12v, +24V.

Specs from data sheets of components will give you operating voltages.

Post a pic of the power supply section so members can comment.

[sc122524]

I was finally able to get the circuit board itself away from the larger frame.  I removed the MOSFETs and tested those and they seem to be okay.  Now I do have access to removing individual components if I needed to test those in isolation from the rest of the circuit board. 

I've attached a screenshot.  The ref circled zone contains the MOSFETS (pre-removal).  The green zone is the area for distributing power to the main treadmill motor.  I had measured the output voltage of that to the treadmill motor and I'm remembering correctly, that was up to 12V.  The pink area was the Incline motor section and relays.  Those are able to run the motor up and down when I directly connect it to the power, but even then they aren't really used for the main motor so I don't think that is the issue.

I've tested the input voltage on the main board itself as 120V, and its running through an extension cable.  I did try and try without the extension cable and it had the same issue.  It seems like the issue happens when it attempts to spin up the motor.  If I am moving the motor when I start, its able to go for a few seconds if I keep moving the walking section but eventually it stops even if I continue to walk.

[BurningTantalum]

Before you go anywhere else with this, it may be worth checking the 'yellow glue'. 10 seconds with a DMM to eliminate a known issue with the glue becoming conductive and also rotting component leads and/or board traces. I have come across this several times, from Japanese audio amps to Chinese modules and a Kawasaki ignition system, and the Chinese manufacturers are still using it so I am informed.
BT

[m k]

If I am moving the motor when I start, its able to go for a few seconds if I keep moving the walking section but eventually it stops even if I continue to walk.

So overcurrent or tachometer missing.

Is "TEST" below green LED for more below connector?
The connector seems to be for serial communication.

[Poroit]

Is there a small Backup Battery (Button cell or similar) in the Control Panel?

I did some work on a Cross Trainer that was throwing up error codes.

A new battery fixed the problem.

I suggest you check that first before you jump into the power supply.

[sc122524]

Sorry for the lack of responses, I appreciate the suggestions that people have offered.  I've been caught up on some other projects with a higher priority that have died down so I can focus on this again.

Answering some of the questions here:

"Is there a small Backup Battery (Button cell or similar) in the Control Panel?"
Unsure, I will take a look to see if I can find a better angle.

"So overcurrent or tachometer missing.
Is "TEST" below green LED for more below connector
The connector seems to be for serial communication."

The tachometer (reed switch) is there that seems to operate properly.  I didn't quite understand your other comment about test.  Are you asking if that is where you would place a test probe to see a signal?  If so, I hadn't noticed that particular area yet, so I can take a look at it.

"Before you go anywhere else with this, it may be worth checking the 'yellow glue'"
I will check the conductiveness of the glue to see if that is it.

"Is it a Switch Mode power supply?
Focus on determining the power supply DC voltages that should be available. eg +5V, -5V, +12v, +24V.
Specs from data sheets of components will give you operating voltages."

I'm not entirely sure, as I'm not really a hardware guy.  Are you saying using a MOSFET to trigger on/of for the voltages for the power supply or something else?  The voltages available were 120v from the wall (obvious), then I believe was around 12v for the motor.  I will take a look again to see if I can get more info.

I managed to test the MOSFETs out of the circuit and they were fine, which was a bit of a bummer as I thought that may be the issue.

[m k]

Close to the top edge is a green LED, between it and a black single column connector is a text TEST.
The connector has pin names indicating serial communication, either it's in regular use or for some add-on stuff.

A bit right from the LED is some text I can't read.
Next to the right is a mostly white component, is it also a LED?

[sc122524]

Here is a closer image of that area.  I believe that is another LED that is used every time to determine when the reed switch is triggered, but I'm not 100% sure of that.

[sc122524]

I connected a logic analyzer to the output from the board where it has the MISO, MOSI header.  I'm trying to see if I can get anything when I trigger the start command, but so far I haven't gotten anything useful (nor do I think I will as I'm not sure its a signal issue). 

[sc122524]

Here are some more photos I took from a doc that Sole sent me to help troubleshoot.