Star Tech Journal

Wnis Black Knight
Faulty Switches
Willianis Whirlwind I""
LED Fade Out
Evan Wessel
Mercury Amusement
Havertown, Pennsylvania
Kevin T. Lee
B&S Music Company
Rome, Georgia
PROBLEM
PROBLEM
If you're having intermittent switch problems or
worse: Check the wire bundles under the upper
playfield for cuts and nicks.
We received a service call on a three month old
Whirlwind pin game. The complaint was that the
information across the LED's was fading away.
CAUSE
SYMPTOMS
The wires hang very close to sharp metal loop
ramps on the lower playfield and may short from
vibration.
The+ I 00 volt supply and the -100 volt supply on
the power board was reading lower than normal
(about+84voltsand-86volts). The 1N4764, 100
volt zener diode was going bad in each section.
SOLUTION
Williams made this game easy to service just by
removing one screw. This will allow the upper
field to swing open for full access to the upper
playfield hardware.
CIRCUIT
The+ I 00 volts is dropped 20 volts on the master
displayboard through DI andD2 (IN4740A, 10
volt zener diodes) and fed into the anode drivers, ~
Ul3, Ul4, Ul 7 and UIS.
TEMP
Data East Time
Machine Lock-Up
Todd Tuckey
TNT Amusements
Southhampton, Pennsylvania
PROBLEM
Game locks up 2 balls, third ball doesn't eject.
CAUSE
Factory wiring error.
SOLUTION
Put game in switch test. Push the switches on
the time lock one at a time starting at bottom.
They should read I, 2 & 3. If the 2 and 3 are
reversed on your game, exchange the white/blue
and the white/green wires on the second and
third microswitches and problem is solved.
Fix
I had no I 00 volt zeners with me, so I jumped out
DI and D2. This raised the supply voltage to
these drivers enough to keep the LED's bright
until I could return with the correct parts.
SOLUTION
After replacing the 100 volt zener diodes and
removing my jumper on the master display
board, the LEDs returned to normal brightness
and the game has worked fine ever since.