Classic Mode

Star Tech Journal

Issue: 1986-November - Vol 8 Issue 9

STAR*TECH Journal
article, but perhaps they will now realize
,-., that they should adopt this nodification
so Betson and/or their customers won't
have to deal with these problems.
I'll never understand why manufacturers
sometimes resist obvious product
irrprovements. Crorrpton, by the way, has
always had II\Y respect as an excellent
manufacturer of rederrption equipment.
I hope that operators will continue to
rronitor this column as I will be
discussing several irrportant nodifications
for cranes, rotories, and other rederrption
equipment. If anyone has a specific type
of application or comnents, we at
Alpha-Qrega Amusements & Sales are
interested in hearing from you. Contact us
directly at 201/287-4990.
*
November 1986 (5)
Back By Popular Demand:
THE VIDEO PROBE
By Atari Field Service Departnent
Milpitas, California
'Ihe video probe is an extremely si.nple,
but invaluable piece of test equipment.
'Ihe probe can be assembled in a few
minutes from cofflIX)nents which are
probably already in your lab. If you do
not have all the parts, you can usually
find them at your local electronic
supplier.
The probe is constructed from a 24" length
of 20 NIK:, (American Wire Gauge)
rubber-coated wire, a 4.7K 1/4 watt carbon
resistor, Paoona or hook-type clip and one
test probe.
'IO .ASS9IBLE 'l'BE P103E:
1. Strip 3/16" off both ends of the wire.
Solder one end to the Porrona or hook-type
clip and the other to one side of the
resistor.
2. Unscrew the plastic body of the test
probe from the point. Thread the resistor
and wire through the hole in the plastic
body. Solder the end of the resistor to
the metal point of the probe.
'IO mE THE VIDm PROOE.
1. Blank the screen by renoving the red,
green and blue inductors (usually Ll, L2,
L3) from the video PCB.
2. Attach the video probe to one of the
red, green or blue test point and touch
the probe to a convenient source of the
suspected signal, while watching the
rronitor for that signal's display.
The video probe displays signals used in
the development of other signals, where
the developmental signals are not
otherwise visible on the rronitor screen.
The probe sirrply picks up the desired
signal and couples it to the video line
going to one of the color guns on the
rronitor, where it is directly displayed on
the CRT.
The video probe is especially useful in
troubleshooting bad or distorted video. By
coupling the video up to the rronitor, we
can trace bad video signals back to its
source.
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!

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