arcade

If an original cabinet and game then the DIP switches on the main circuit board are what you are after. A search engine search for the game, plus the word 'manual' should help you. In MAME it's one of the 'F' buttons on the top row of your keyboard, but i'm not sure which..'F5' or something. I know that such games as Defender initially start up with the Factory Settings screen and you have to press'F3' to reset it for play. After that first time the game is playable every time.

You can try taping a piece of string to a quarter and then pulling it back up again.