Fuji Exceed only fires balls if I'm touching metal?!?

[AchillesPDX]

Hi people, I just snagged this (my first machine) off Craigslist today and I can only get it to launch balls if I'm touching the metal ring around the handle AND I briefly touch another bare metal piece in the back.

I assume the metal ring around the handle is some kind of capacitance test to make sure something with flesh is holding the handle down, but I can't for the life of me figure out why it needs to be "jump started" by briefly touching something else as well.

Any insight would be great. This is my first experience with Pachinko, so maybe I'm just missing something obvious - please be gentle