Star Tech Journal

STAR*TEcH
Journal
SF"' on
CD-ROM
Every tech tip, game mod, test
procedure, Mfg change, update,
upgrade, precaution, etc.
for virtually all coin-op games
produced from
1979 - 1995
Every page (over 5,000!) of
STAR* TECH Journal
Now available on Disc!
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April 1996
CD
WILLIAMS
UNIQUE
lAcK•Bor a CONGO
T'SHOOTING
Loss OF BATTERY
PROCEDURE:
VOLTAGE
UsEA VCR!
Williams Parts & Service
Williams Games
Chicago, Illinoise
Rod Onotera
Game Service
Winnipeg, Manitoba, Canada
GAMES
SYMPTOM
jack•Bot and Congo sample games
manufactured before 12-15-95.
I had what I thought was and in-
termittent problem with a ma-
chine that would seem to go into
a slam mode but I wondered if
there could be a specific combi-
nation of events that caused the
problem.
PROBLEM
Premature loss of battery voltage
on the WPC-95 CPU Board.
IDENTIFICATION
The CPU boards affected have
the bare board part number of
5764-14533-08 (screened on back
side of board). The circuit boards
should have been modified in
house, but in case any were
missed, please perform the mod.
RESOURCEFUL
AVAILABILITY
SOLUTION
Contact your distributor or Will-
iams Games Field Service for
details on this modification kit.
I was able to determine that when
the right flipper was energized, a
target switch was closed and
when another target was hit ( clos-
ing another switch), the switch
matrix would erroneously read a
slam because of a bad diode on
one switch. I was able to
reproducethe "intermittent"
problem and correct it.
I couldn't follow the ball as it
moved too fast, so I caught the
problem on video by taping play
with a camcorder mounted on a
tripod and playing the tape in
slow motion.
ULY:Olt-1:l
Journal
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