mjb1970a

I see someone else had a similar issue

mjb1970a

Hi gsa. Any tips on how to get into the PCB?

unterhausen

asking questions doesn't require posts. If you want to post a picture, then put it in your gallery and I'll rescue it for you.

I would like to know where this circuit board is, don't want to have to probe around.

I want to see if I can put a better antenna on it.

gsa103

No idea, I don't have one of those trainers.

mjb1970a

So I've managed to get into the Core. Does anyone know which bit fails when the pcb goes? I'm hoping to get it repaired as wahoo aren't being as helpful as I'd hoped. My ideal solution would be me buying a new pcb but I can't locate one. I can't post the photo until I've made a few more

mjb1970a

Posts

bikebikebike

Does Wahoo sell the circuit boards as part of support?
Board failures from static etc were warrantied and they were pretty good about support
and appeared to iron out early problems in later models
I was looking at used ones, and the ability to repair reasonably is as good as a warrantee for me.
Achooly better. I love the smell of flux in the morning.


Out of curiosity, anyone have links to teardowns or wiring diagrams a trainers?
Ive seen repair vids for the Wahoo online for other issues.

unterhausen

My understanding is they don't have boards for repair of the original, can't get any, and they offer you a discount on a refurb. Hopefully I don't have to find out if that's true or not.

unterhausen

put it in your gallery and I will post it for you

Cturrin1

do you know how to repair the circuit board if the wrong power supply was plugged in? I’d post a picture but looks like I can’t.

unterhausen

You can upload pictures to an album in your gallery and we can rescue them for you.

I have never heard of a repair for this, but I imagine it's possible if it doesn't blow the microprocessor.

Cturrin1

I added some pictures in my album. If I need to do something else please let me know. This is my first time to post here and I’m new to this. Also if this helps: When the board is plugged in the kickr doesn’t work. But the circuit board still gets power. The brake engages but nothing lights up. It may be the main box on the board but it could be some other part and don't know where to locate parts. I accidentally plugged in the wrong power cord and wrong voltage.
Thx again for any help.

unterhausen

Unfortunately, it says there are no uploads in your albums or photos. You have to select the pics, it looks like they should be uploaded, but there is an upload button on the upper right side that completes the action.

Cturrin1

OK I think I uploaded them. I appreciate your patience with my tech challenges. there should be six pictures of my circuitboard. I tried uploading here but I don’t have 10 posts yet

unterhausen

Looks good.

unterhausen

Okay, you have to love FCC test reports. There is also a users manual for the radio module
That board has test points all over it, so you should be able to get a good idea of the state of the power supply.
The module itself is mostly a nRF52832 in a shielding box.
https://www.google.com/search?q=gems...hrome&ie=UTF-8

Cturrin1

That’s amazing information. Thank you. I can’t tell you how much time I’ve spent searching for information. I wish I understood it. Lol. Do you know anyone that could fix it?

gsa103

Most of the time it'll fry the voltage regulator, and hard to say what else after that. The voltage regulator is probably U5, but I can't read the label on it to confirm. I'd say it's 50/50 as to if it's fixable. At a minimum, it's a fair amount of following traces and SMT re-work.
If the voltage regulator fails open, it probably put 24V on the main controller chip, which would definitely kill it. That's a replaceable module, but there's no way for anyone (other than Wahoo) to program it.
I personally have a full SMT re-work station, but it would take me some time to trace the circuit. Then ordering replacement components and hoping the original event didn't fry the microcontroller. Best case it's several hours and you get it working.

Your best bet is going through Wahoo, who probably want you to send the entire trainer in. Which makes sense from their perspective, that way they send you a fully functional trainer.

unterhausen

I think wahoo can repair everything but the version 1 kickr. This doesn't look like a V1. Okay, it's not, I can see the handle in one of the pictures.

And get rid of that other power supply

The power regulator is U3, it's an MC33275- something (3.3v)
MC33275DT−3.3RKG
Didn't see an absolute max input voltage, they just say input voltage is 13vdc

https://www.onsemi.com/pdf/datasheet/mc33275-d.pdf

I always wondered if it would help to replace that chip antenna with an external antenna. Doesn't look particularly easy

The module manual says how to upload firmware via a couple of pins. Getting it from wahoo would be a bit of a hassle, but they let you download it. https://fccid.io/PADWF116/User-Manua...Manual-3085164

unterhausen

Interestingly, the OP was wrong, VNH21 identifies his mosfet just fine. It's one of these https://www.onsemi.com/pdf/datasheet/ntd4810n-d.pdf

Interestingly they seem to have switched from an N channel to a P channel between these two boards.

Cturrin1

I’ll see if I can decipher through this foreign language of information that has been given to me. I am not a mechanically inclined person so much of what’s in the manual doesn’t make much sense. I also reached out to Wahoo. I appreciate the feedback and the knowledge that’s been sent my way in such a short period of time.

unterhausen

I think the best thing to do is go through wahoo. If that doesn't work out U3 is available. Not sure where you are going to find someone that can desolder/solder that on the board though. They are all around us, but hard to identify. I assume that is blown. As gsa103 said, it's possible it blew as a short, which would be bad because the whole board would have been exposed to high voltage. Let's hope it blew open circuit and was the only thing that died.

It costs 90 cents from Digikey https://www.digikey.com/en/products/...-3-3RKG/920890

Cturrin1

If you can fix I’ll ship it to you. 😬

aceaminolab

Have you replaced the damaged N-channel mosfet?Is this the only logic board for Kickr?

unterhausen

Welcome to the forum. Hopefully Wahoo got him sorted. Someday I'm afraid I'm going to have to start a kickr V1 support group.