It's been a couple of years ago, and I didn't have a digital camera then. As I recall, the mechanism was a little gunked up from years of crud going into the switch. When you push the button, I think there was a little disk underneath that had the switch contacts. This disk rotated slightly and closed the circuit. That's all I can recall. but it wasn't hard to fix, as I remember. Just be very careful when disassembling so you know exactly how the parts go together.