Hello!

I’m really just a beginner when it comes to electronics. I can do some soldering and have built a couple of keyboards.

Now to the point, we have an home exercise bike (Master B20). We bought it used and tested it once.
On the back of the display there’s an on/off button/switch. My three years old daughter somehow managed to remove this button (poking it with a stick I think).
You would think the button should end up inside the housing for the display. But after taking it apart the button is gone. It is completely gone, we have searched everywhere.

If I only had the button I would be able to fix it, but now I can’t really figure out how it worked. (And I don't even know how the button looked, if it was a switch or push button).

So the problem is that we can’t start the bike. I really don’t need a button for it (we only plug it in when we’re using it). So I thought I should be able to just solder a wire where the button was to close the cuircuit.
The problem is that there are five ”pads” (not sure if that’s the correct word).
And I don’t know which of these that should be connected.

I have tried to do some testing with a multimeter to see how stuff are connected. But I can’t find that any of these five pads has a connection to where the power supply comes in.
As I said, I'm really not good at this. But I upload some images of the pcb here and hope perhaps someone might give me a few hints.
Thanks!

Bellow are some images.



This is the back of the display where the on/off button was, when looking down you see these five pads labeled "ENCODE".


An overview


Here you see the "ENCODE" part above which the button was located.


A closer look

 

Welcome to AAC!

I am going to guess that the ENCODE pads have nothing to do with the ON/OFF switch. Is there a pair of wires hanging loose? I would suspect that the switch is a “soft” power switch. Power does not go to the switch.

Have you tried contacting the manufacturer or visited a retailer to examine a floor model?
Is there any information in the User Manual?

 

Agree with @MrChips. Those pads show no evidence that anything was ever soldered to them.

What are the wires that go off the picture connected to?

 

Hi,
It is possible that the missing plastic part had the copper contact links on its inner face, which made the correct contacts when pressed?
E

 

Hi overtune.
Is this video any help?
E

 

The bike in the video is not an “exercise bike” as stated in the OP.

 

Hi Bob,
I used the exercise bike (Master B20 for the search.
Guess we will have to see if the TS finds a solution.
E

 

It appears to be this exercise cycle.

https://www.masterfitness.se/sv/motionscykel-master-b20-2kauEY4

 

Wow! What a helpfull and welcoming place! Big thanks to everyone that has provided answers!

Yes, I think @MrChips is correct that it is a soft on/off switch. But there are no loose wires.
Could it perhaps be as @ericgibbs suggests that the switch had some coppar plates and when the where pushed against some of the pads on the pcb the chip started?

@BobTPH the two wires going off to the sides are for the heart rate monitors in the handlebars.

It is not the bicycle in the video posted but the one @MrChips linked to here:

https://www.masterfitness.se/sv/motionscykel-master-b20-2kauEY4

I have taked to the manufacturer. They didn’t have any on/off buttons as spare parts (but they did search their warehouse for some broken display to send me but without success).
They only provide the full display unit as spare part. I could always buy that, but it feels a bit unneedfully when it’s only the button thats missing/broken.
(But if I end up buing a new display unit I will for sure take it a part to look at how the button looks ).

The manual for the bicycle only goes through all parts of the bicycle, nothing regarding how the display unit looks.

But thanks for all your input!

 

The manufacturer went to the trouble of gluing all those cables. It seems unlikely that they would use a switch that just sat on top of PCB pads.

Ask the manufacturer what switch was used and how it is connected to the board.

 

Hi overtune,
As you are in contact with the manufacturer, ask them to post you a photo of the inner face of a plastic push button, used on that model of the bike. [the button part you have lost].
This should give you a clue on how the power switch operates.

E