Do not attempt to replicate what I demonstrate in the post below.
High risk of electric shock!
You have been warned!
This story started a long time ago. Like late 2014. I was fixing a United Singapore bingo machine. Everything was going well. The machine was ON and plugged in. Then, I touched the trip bank assembly reset arm and got a shock. Nothing dramatic but it was quite a zing.
I immediately suspected the large 120V reset coil, something like the coil's winding was shorting to the brass sleeve.
Back then I only had a crappy multimeter that didn't go into the megohm range.
Heck! It didn't even go that deep into the kiloohm range so when I measured between the winding and the brass sleeve, it measured open circuit. So based on my dodgy measurement device with a very limited range, the coil tested OK. Seemed fishy and I suspected the multimeted wasnt sensitive enough.
Fortunately, I had a spare coil, swapped it out, and no more getting zapped by the trip bank reset arm.