october 1994
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KoRTEK
WELLS GARDNER
WMS STAR
TREK:
MONITOR
PARTS SOURCE
NG
HORIZONTAL
RANGE CAP
PROXIMITY Moo
Rich Risius
Moss Distributing
Des Moines, Iowa
Sid Craun
State Sales & Service
Baltimore, Maryland
John Liikala C.E.E.T.
Canadian Amusement Games
Burnaby, British Columbia
PROBLEM
PROXIMITY SENSOR
PROBLEM
I am having trouble finding some-
one who knows anything about
Kortek monitors. I have one that
has a ripple or hum bar that runs
vertical and pulses the screen.
I've separated the power supply
out of the circuit and put a load
on it, and with a 'scope on the
load I still have the ripple. I've
replaced the zener diodes, tran-
sistors, and all the capacitors in
the power supply but none of that
has helped. Also can't adjust B+.
A condition exist when the eddy
sensor (switch matrix# 16 &17)
is closed, any opto switch on the
same related switch row might
change state. (If closed, it will
read open and vice-versa). This
problem is fixed by cutting a
trace and adding a IN4148 diode
on the proximity sensor board.
To expand the horizontal range
on Wells Gardner K7000 series.
SOLUTION
Marc Mandeltort
Marco Specialties
West Columbia, South Carolina
Sounds like you need a "Get
Well" kit. Zanen Electronics has
get well kits for the Kortek moni-
tors as well as tech help on same.
SOLUTION
If you are adjusting the horizon-
tal frequency on this monitor, try-
ing to eliminate that one side that
has a tear in it, and over-adjust-
ing causes the picture to lose the
horizontal sync, try the following
capacitor change:
PROCEDURE
• Cut the trace going to the
collector of Q3 on the com-
ponent side of the board.
• Install the diode between
pin 4 of connector Jl and the
collector of Q3. The cathode
of the diode goes to Q3. This
is done on the solder side of
the board.
!!I
·~
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CHANGE
FROM
1 mfd/25 W volts
1
I
I
TO
10 mfd/35 W volts.
@
J:t:Jlllws.tisR122a:+1aaw]·· · •
.rv1FG PHONE
&
C22
FAX
See page 2 7 For updated rnanuFacturer
Customer Service phone & Fa.x nurnbers.
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