Several years ago an acquaintance gave me a steampunk toy pistol. I noticed that there was a trigger that moved and the front barrel rotated but didn’t think much of it. It looked like it was supposed to do something, but I didn’t pay that much attention and it sat on my bookcase for over a decade.
A couple of days ago I saw something I had never noticed before – it had “3V” molded into the plastic. This was a battery-operated toy which did something! A couple of turns with a screwdriver revealed the hidden battery compartment with two AA batteries.
Step 1: Determining What Wasn't Working
The most obvious solution is usually the best – could it be dead batteries? Nope, the batteries were fine.
I unscrewed the remaining screws and took the toy apart. Besides the primary circuit board with the LEDs and buzzer there was a smaller board with a built-in membrane switch mounted next to the trigger. I pressed the switch and was happy to hear the sound effects and see the lights – problem almost solved.
Step 2: Solving the Problem
It turns out the plastic trigger wasn’t hitting the switch hard enough. I thought about gluing a tiny piece of plastic to the end of the trigger to extend it but that would be fairly tricky since it had to fit into a very small space. Then I recognized that all I needed was some kind of spacer between the trigger and switch. I couldn’t find a piece of plastic which would fit but then inspiration struck – how about a piece of cardboard cut to size?
Yup – a tiny piece of cardboard placed over the switch did the trick. The plastic trigger presses the cardboard and it provides enough pressure to activate the switch. A piece of tape keeps the cardboard in place and ensures it won’t slip.