Star Tech Journal

STAR*TECH Journal
Novembar·1s86 (6)
Williams Notes: EOS Switch, Flasher
Circuits, CPU Reset & Pin Relays
Sol. B+
by Fritz Runyon/Publications
Williams Electronics Games
Chicago, Illinois
END-OF-STROKE (EDS) SWI'ICH CONNECTION
'!he Power Wiring Diagram in the manuals of
the several recent games (HIGH SPEED,
GRAND LIZARD, and OOAD KINGS) shows a
connection error. {Games are correct; only
the diagram was in error.)
The manuals show the EDS switch on the
flipper connected from a winding tap on
the flipper coil to the cathode terminal
(bar across the triangle, or banded end)
of the diode. The actual ros switch
connection is from the winding tap on the
coil to the anode terminal {triangle
base, or unhanded end) of the diode.
FLASHER CIRCUIT
An accidental omission of the flasher
lamps circuit occurred in the manuals for
HIGH SPEED and ROAD KINGS. (It did,
however, appear in the GRAND LIZARD
manual!)
The lamps are in series with the Solenoid
B+ line, which obtains its lighting
turn-on signal via the applicable solenoid
drive line. The lamp circuit connection is
between a 5 Ohm, 10w resistor and a 330
Ohm, 7w resistor.
(Incidentally, a pair of these resistor
circuits is now available on a PC board
for better reliability; its part number is
C-11233.)
~ .~~~
~.,.,.,.,.,.,.,.,.,~.,.,.,.,.,.,.,.,.,.,1
~ so , ________ 3300 ~
Solenoid
Drive
if.
L
if.
~ 10w
?'
.,.,., .,.,.,.,.,.,.,., .,.,.,.,.,.,.,.,., .,.,., ., .,.,.,.,., 7w
.,.,.,.,.,., ;/. ~
~
112-C-11233ResistorCkt. Bd.
•
189 Plasll.lamps Circuit
For your information the following table
shows the flashlamps used in various
games.
Flash-
Game
lamp#
Comet, High Speed,Grand
#63
#89
#1251
Lizard, Road Kings
Pin•Bot
Pin•Bot (Visor & Insert Bd.
Robot face)
11 CPU RESET
If a game (HIGH SPEED, GRAND LIZARD or
ROAD KING) occasionally resets during game
play, check the various solenoid coils
(flippers, drop targets, eject holes,
etc.) for a broken diode, or an open diode
circuit produced by a failed diode or a
'cold' solder joint.
SYSTF.M
Sometimes, one or more of these diodes has
broken loose (perhaps physically, but
certainly electrically) from the circuit
{and thus shows as "open"). Such an "open"
diode allows electrical "noise" to feed
back into the CPU causing it to reset.
Resolder any suspected 'cold' solder
joints, and replace any broken/faulty
diodes (1N4004, or equiv.) to prevent this
noise feedback.
~
Solenoid
Drive
163 Pwblamps Circuit
When replacing coils {from Williams or
other sources) on solenoids or flippers,
always test the diode for proper
electrical operation!