11/11/2025 8:15 PM - Made the PCB outline in FreeCAD and created KiCAD schematic.

I begun 10 days ago when I started Reverse engineering the schematic. It seems it's a simple push button with debounce cap.
Then I went on a quick look to find the used buttons, caps and one connector. I wasn't lucky as I don't know the values of the caps. I'll ask my friend to borrow one tomorrow. I wasn't able to find any buttons that would look like it using google lens. Then I went on the connector and I was able to find a redit post talking about the connector type. I need to do thorough research on these! Like read the datasheets. lol

The I started a FreeCAD project. More on that in another Journal.

11/11/2025 8:22 PM - Made the PCB outline in FreeCAD.

After that I wanted to do do the PCB outline.
At first I didn't know which program should I use. I'm still not quite sure. So I started with a vector program called Inkscape but I wouldn't be able to iterate on the design much so I've switched to a parametric modeler FreeCAD. I used CAD software for RE before and I still find RE quite finicky and weird.
So I developed a workflow to Model in FreeCAD with the help of calipers and import it into Inkscape as SVG. And print it on my paper printer.
At least that was the final process after finding out that my Prusa MINI isn't dimensionaly correct. And finding out when you print white stuff on white paper it spits out a blank page.

These look so pretty;)

11/16/2025 - Found the Button and connector

Search for the lost button 😅

Firstly I went about finding the button used.
So I've went on LCSC and opened Tactile Switches and inserted the parameters. I choose a square, ~3.2mm with which is what I measured and not to forget the height of 0.7mm.
And I was able to find three buttons which seemed like they would work.
It doesn't have the little nub in the center.
I think it's because the two surfaces meet there and rub on each other.
If this becomes an issue I can still use the buttons from the broken board.
I'm giving my best hoped to this one.

Search for the connector

Then I went on finding the right connector.
I've seen it on phone batteries

IDing it - it's a madness

With the help of google lens I was able to find a reddit post IDing the connector.
And I saw that they are called mezzamine connectors so I typed that into LCSC. Sure enough I saw the right types.
Next I took a look at the filters and I know it's a 0.35mm pitch with 5 pins on each sides. I've double checked it with calipers and I wasn't able to see anything with my bare eyes so I used my phone in macro mode as a microscope. lol it worked surprisingly good.
This one was my first guess so I looked in the datasheet to find out more information as I may missed some. After looking in the datasheet I noticed that the shape is a lot different.
So I looked one more time to a liked connector selector and I've noticed that the A35S seems to match. I wasn't able to find the 10 Pins variant as on the connector finder. So I G. Lensed it and I was able to find PANASONIC AXF5A1012A on mouser so I've put it into LCSC and after checking the dimension everything seemed to be correct but the with and conn pin with wasn't. Ahhh here we go again.
So I have busted out my microscope from childhood to look at it closer. And ... I've thought it was better. 😅
Then I realized that I have a DSLR with super macro lens. I shot a lot of photos and that's where I left it for today.
Total madnesssssssssssssssssssss

11/17/2025 - The seach for connector continues.

After shooting a few super pretty photos I was able to focus merge them together in affinity photo V2. These turned out super awesome.

I've messaged a guy on reddit that seemed to have figured this connector type. And he didn't post final results. viz reddit post
After that I went on the hunt one more time.
I've looked on digikey and LCSC one more time with no luck.
So I've given up on this and begun writing the connector constraints or whatever its called into a MD document.
After that I have used ChatGPT along with the images. And it pointed me to a Hirose series's which didn't seem to be right.
So as a last effort I used aliexpresses lens like search on images I shot earlier and to my surprise it found it!!!!!
https://www.aliexpress.com/item/1005008694283451.html It isn't it 😭

I never been on Hirose site lets see https://www.hirose.com/en/product/series?category=Board-to-Board-Board-to-FPC_Mezzanine-Connection
Only BM20 seems like it should be right but it has 0.5mm pitch.
I have s sneaking suspicion that it may be 0.3mm pitched. Let's head to LCSC and Digikey part piskers! Maybe octoprart.
Nope
Time for a pivot.

11/18/2025 - I'm not sure if I want to continue

I've learned with this experience that reverse engineering is super hard.
Props to the original engineers as they did a great job.
It's so impressive to look inside of devices. I love the audio stage. Like the whole point is sound.
I'll probably just settle with soldering the broken sides together. 20 hours sunk into RE lol. I see it as a learning opportunity!