How They Work - Opening the Shutter Panel
OK, assuming the shutter panel is closed, it should immediately open when you initiate a machine cycle unless:
- you are playing for extra balls
- your game has a stop-n-shop score booster feature.
The shutter motor cam switch 5A is connected along the green line when the shutter panel is closed. If the shutter panel is already open, the 50V gets directed down to the timer cams and mixer latch coils to perform the spin cycle. The green line circuit gets the shutter motor started on it's way to opening.
The shutter motor turns 180 degrees every time it gets powered, which is handled as always by a carry-over cam/switch (shown in orange).
The purpose of the purple circuit through the shuffle relay is
described below. It's interesting in that the shuffle relay actually
stays closed long enough for the shutter panel to go through
a complete 360 degree close/open/close cycle.
Primarily, shutter cam switches 3 and 6 pulse the reset coils on the various stepper units in the game. Most of these reset coils are shown on the schematic in the lower right corner. In addition to these reset coils, the timer unit reset coil and the trip bank reset coils (or motor) are controlled by shutter switches.
Or put another way, when the shutter panel opens, most of the
game is reset. Except, of course, in this game and a few
others that have the
hold feature or
other bonus game features.
Since the hold feature allows dropping some balls from the
playfield so they can be reshot, we can't allow the game to reset
while the shutter panel is moving to drop the selected balls.
That's why the shuffle relay is showing up all over the
place. While the game is doing the hold function, the shuffle
relay switches open so the reset coils don't get powered.
Besides pulsing reset coils, switches on the shutter motor
unit are used here and there to make sure the game doesn't
do daft things during reset. For example, the 50V to the
payout circuits is cut off unless the shutter is closed.