If this is a dedicated MK3, use the row of switches on the coin door to enter
test mode and use the joystick to move up and down in the menu and the buttons to select.
If there are no test mode buttons, set DIP switch #8 on the game board and it
will put you into test.
When finished, turn DIP switch #8 back off.
Also, if you adjust the settings and they dont stay after turning the game off and back on, your battery on the board could be bad (game will say CMOS SETTINGS or something similar on bootup if the battery is bad)