Star Tech Journal
Issue: 1994-September - Vol 16 Issue 7 - Page 7
WILLIAMS OPTICAL SWITCHES:
RELIABILITY
& TESTING
Evan Wessel
Mercury Amusements
Havertown, Pennsylvania
SERVICEABLE?
Most operators are
having difficulty
identifying and re-
pairing these cir-
cuits which are of-
ten intermittent.
Reliability can be
improved by stron-
ger component
lead
strength
which can hold up
to vibration. This is
especially true in
under playfield
ball troughs.
Kerry Messana
Service Technician
Syracuse, New
York
DON'S
VI DE 0
CORNER
Video Card
Games
CONCERNS
I'm sorry to say that the wide-
spread use of optical switches in
newer Williams pinball games is
causing reliability
problems.
1'._"'rAR TECH JOURNAL
read open. It is sometimes tough
to block a set of optics especially
on a game like Star Trek: TNG.
"Most opera-
tors are having
difficulty
identifying and
repairing these
circuits which
are often
The flashlight
aimed at the re-
ceiver can check
out the photo
transistor, if the
sender is suspect.
Also, if you take
a voltage reading
across the sender
you should read
about 1.2 to 1.5
volts De.
• If it reads
around 12v it is
open (I have seen
a few of these).
• If you read zero
across it, the cur-
rent limiting re-
sistor is open.
OBSERVATION
Yes, I too have
TESTING 0PTOS
seen a lot of fail-
There are a couple
ures with these as
intermittent."
sneaky ways to
well as a lot of
check out these
CPU controlled
optics. You can
lights blown on
check the optic set out by short- Star Trek: TNG -especially the
ing the sender leads together.
top lanes.
This should cause the "switch" to
8 Line
Machines
Don Powell
DoN's V10Eo REPAIR
Shelbyville, Tennessee
ELECTROSPORT
POKER
DECODER
RAM CLEAR
SYMPTOMS
Blue video lines and no
game functions at all.
#1
7H Decoder bad.
Replace.
SOLUTION
#2
Clear Ram.
To completely clear Rams
( turn game off) short Pin
18 of 9C to ground.
Reset menu.
SOLUTION
Future scanning projects are planned by the International Arcade Museum Library (IAML).