Star Tech Journal

STAR*TECH
Journal
February 1 995
CD
SEGA PINBALL MAVERICK OPTO' s
A TECHNICAL OVERVIEW
Joe Blackwell
Eric Winston
Ted Kilpin
Sega Pinball, Inc.
Melrose Park, Illinois
We have designed out Opto's to
operate as closely to the action of
a switch as possible and even
more importantly the trouble-
shooting procedure used to diag-
nosis a problem is very similar to
that of a mechanical switch.
SwrrcH TusT:
Blocking the light beam causes the
Opto to respond like a closed
switch, the same as actuating a
mechanical switch.
TROUBLESHOOTING:
1) Enter diagnostics; Switch test.
2) Block beam; does it respond in
test? Yes=OK No=continue
3) Visually inspect transmitter; is
it glowing red? Yes=OK No=Check
2 pin connector for 5vdc.
NOTE
We use Ultra-bright visible red
light L.E.D.'s so that no special-
ized tools are required for trouble-
shooting. They also have a nar-
rower bandwidth when used as a
receiver so that ambient light has
little to no affect on them, unlike
infrared L.E.D.'s which have a
wider bandwidth.
. . .
4) Visually inspect the Receiver
Bd. for damage or loose connec-
tions. Remove the 2-pin connec-
tor with the green and white wire.
Using a jumper wire, short the two
wires together. Does the display
indicate a switch closure?
Yes suspect bad receiver or receiver/
transmitter misalignment.
No suspect open in switch matrix
wiring .
REMEMBER
The transmitter is acting as noth-
ing more than a flashlight -if it is
on, then it is working. If shorting
the Switch Drive/Return lines on
the receiver side together indi-
cates a switch closure, then, like a
bad microswitch, your Receiver
Bd. is bad or misaligned. The cost
is approximately the same as a
microswitch -only the board is
repairable.
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