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correct composite video signal. The entire
Sensitivity of the static modification feature may be
adjusted with potentiometer R56, or by changing the length
of the antenna wire, or through a combination of both of
these. Drawing number A003750, the PCB assembly drawing
included in Section VII of this manual, shows the location
of this potentiometer near the edge connector end of the
PCB. Lengthening the antenna wire increases sensitivity, so
that a lesser charge will turn off game credit. Cutting the
wire shorter decreases sensitivity, so that larger charge is
required for triggering the circuit.
If there are problems with static charges accidentally
shutting off the game, try cutting the wire shorter, in
increments of½ inch at a time. Be aware, however, that if
the antenna wire is cut too short, players may be able to get
free play sequences by inducing a static charge in the game.
The TV monitor is a self-contained
unit housed in its own chassis. A trouble's cause may be
narrowed down to the monitor -either by the substitution
method using a known-to-be-good monitor, or by verifying
presence of AC power to the monitor power supply and
presence of the
monitor can then be removed from the game cabinet. Doing
this facilitates troubleshooting steps, because all monitor
components will then be accessible.
A schematic diagram of the monitor circuitry is included
in Section VI I of this manual. After disconnecting and
removing the monitor from the game, standard TV trouble
shooting techniques arc adequate for locating causes of
trouble. Additional servicing information is available from
the monitor manufacturer (Motorola).
game docs not respond, first check the coin mechanism. If
pressing the coin rcjcctor button forces the rejector mechanism
to return the coin, then examine the coin to make sure that
it is genuine. If it is, then use a set of your own test coins
(which should include both very new and very old, worn
coins) to determine whether or not the player's coin is under
size or underweight If your test coins are also returned, this
indicates that servicing of the coin acceptor portion of the
coin mechanism is called for. Generally the cause of this
particular problem is an improperly adjusted magnet gate.
Inside the coin mechanism a magnet is used to test the
metallic composition of the coin. Highly magnetic coins, such
as those made of steel or iron, will be retained by the magnet
and can be returned by actuating the wiper operating lever.
Coins having comparatively high magnetic properties will be
slowed down by the magnet, and will drop off the end of the
rail short of the "accept" entrance and be returned. Coins
having little or no magnetic properties, such as brass or zinc
coins, will pass through the magnetic field so fast that they
will overshoot the "accept" entrance and be returned.
26
6.3.2 TV MONITOR:
6.3.3 COIN MECHANISM:
If a player inserts a coin and the
A magnetic gate adjusted with too large a gap may pass
both genuine and counterfeit coins. An adjustment with too
small a gap can lead to rejection of some or even all coins.
Over a period of time, the screw that adjusts the magnet gate
has a tendency to work loose, resulting in a gradual narrow
ing of the gate. At first, only the thickest (i.e., newest) coins
arc rejected. As time passes, more and more coins are
rejected until finally player complaints lead to the calling of
the game repairman.
If pressing the coin rejector button does not cause the
coin to be returned, and if the game still does not respond,
then check the coin mechanism to see if the coin is jammed
inside.
If you are certain that the coin is genuine, and that the
coin passes through the coin mechanism and into the cash
box, then the lack of game response is probably due to some
kind of electrical trouble. Check for signals at the electrical
contacts of the coin mechanism before moving on to the
harness and other parts of the circuitry.
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