I've fix it!
I suffered from the not working release button also. What I've done was soldering the pads of the release button. The button is placed on flex ribbon, which may be a problem because soldered pads may break after many pushes.
I will describe what I've done exactly in case You want to try this fix by yourself.
I've reheated three pads of the release button that are marked as 2. Those are easy to access. I've tried to solder the pads that are marked as 3, but those are hard to reach because the other switch is to close. Nevertheless, the pad most to the right from the group marked as 2 seams to be the problem (pad marked as 4).
My camera is working now 🙂
As a side note: Before I’ve fixed the problem, I've tried to shut a photo with the camera case disassembled. When I pressed the release button, I could not trigger my camera, same way as all S100 owners in this discussion. Nevertheless, when I was pressing the trigger button and I pressed the flex ribbon in a place close to the button and marked as 1, then a picture was captured. I’ve done this few times, and it has always triggered my camera. I assume that pressing the ribbon distorted the broken solder in some way and the proper connection was back. I’ve probed the pads of the release button with camera switched on. When the second stage of the button was pressed and released then the pad marked as 4 was switching between hi and 0V states. Therefore, I assume it is the faulty pad.
Good luck anybody that still uses their S100. I am going on my vacation next week and I hope to capture it with my fixed camera!
