Make sure you look into that--probably not static shock, probably a good line level voltage shock due to something screwed up in the cabinet.
Take a voltage meter and meter the coin door to the wall outlet ground or neutral pin with the meter on AC. You should get 0 volts. If you get anything above that then you possibly have a power cord that is wired backwards, or the ground pin is cut off an you have it plugged in upside down. Or your wiring in your house has hot/neutral reversed. I've seen this exact problem on other Bally/Midway cabs. In one case it was the cab, and the other it was the wiring to the outlet.
If you don't have one of those instant plug testers for your outlet, just take your AC tester and make sure it's connected correctly there in the wall.
The small slot is the HOT and the longer one is NEUTRAL. The round of course is GROUND.
You should have 0 volts AC between Ground and Neutral. If you see voltage here you either have a bad ground or if you see 120 V then you have a swapped hot/neutral.
You should have 120V +/- 10 Volts between HOT and either ground or neutral.