STAR*TEcH
Journal
April 1995
WILLIAMS
BIACK KNIGHT 2000
PLAVFIELD TILT TROUBLE AREAS
SYMPTOM
A Williams Black Knight 2 000 that
will tilt for no reason. Have
swapped MPU's and software
with no results. The tilts are all
unhooked and all suspect diodes
were changed.
ode on a playfield switch or
miswiring on another row in the
matrix. I have faced this symptom
several times. Douglas McCallum,
Shiawassee Technical Services, East
Lansing, Michigan.
1
Check resistor pack and drive
transistors on CPU switch strobe
circuit. Make up your own resis-
tor pack if you don't have the of-
ficial Resistor Pack.
2
Make sure there is a good connec-
tion on the drop target opto
board. If the connector is loose,
it will cause all kinds of false
switch strobes i.e. tilts, extra cred-
its etc. I had one drive me crazy
for months! Pete Rondeau, Staff
Amusements, Hanover, Pennsylvania.
SOLUTION
If game still tilts after swapping
CPU board, make sure power
supply isn't intermittent.
SoLurION
3
On all Williams' pins you first
have to check the switch drive
transistors. They are 2N5550's on
Black Knight 2 000. They usually
do not go bad however. The older
2N3904's used to though.
SoLurION
Most common way that the
playfield can tilt the game (with
tilts disconnected) is a shorted di-
,.
And lastly, I would check the coin
door switches to see if any diodes
are crushed and shorted to them-
selves or to something else.
Also, make sure to remember to
check the High Score Reset switch
on the triple button assembly, col-
lectors love to hit that bunch of
switches when pulling the cash
box out! Kerry Messana, Service Tech,
Minetto, New York.
"'I
STAR* TECH Journal nei-
ther operates, distributes
nor manufactures coin-oper-
ated equipment. It's sole
purpose for being is to com-
pile technical and informa-
tional data considered valu-
able for dissemination to its
paid subscribers. Com-
ments or suggestions per-
taining to this service are
always welcome.
...
symptoms you describe. Another
hot spot on Black Knight 2 000 is
the bottom of the upper playfield.
The stainless guides that lead to
the "Lightning Wheel" ( on lower
playfield) are notorious for cutting
into the wires tucked under the
upper playfield.
Another place to look is at the
drop target boards. Williams
made available a modification to
them. The boards that needed
modification were green. If it has
been modified, you will see parts
added on ( a diode or two). The
updated boards were blue by the
way.
Another place to check is on other
switches. A wire soldered to the
wrong side of a diode will give the
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