Star Tech Journal

)
AtariTempest Low
High Voltage
RandyTeny
Alpine Amusement
Connersville, Indiana
Beckman
DM25XL
Multimeter
EASY
ro UsE,
LARGE DISPLAY,
Low Cosr!
SYMPTOM
Wells Gardner 19K6101 picture too large.
•
CAUSE
Video B+ and high voltage low.
SOLUTION
This one had me baffled for a while! I checked (in
H.V. power supply) C90 I, C905, C902, Q900,
Q901, Q902, Q903, R903, R904, R905, R906,
R907, 2D901 and 2D902. All checked fine!
So I started changing parts (thinking a cap or
transistor was breaking down or leaky under
load). I change all the caps, no help: all the
transistors, no help. I even changed the resis-
tors, no help.
SOLUTION
As it turned out, ZD 902 was regulating but at
about 110v instead of 150v. Replaced 2D902,
everything's fme. I had to replace IC90 I (555
timer) and T900 (flyback) right off the bat so they
were known good. Next time I'll take two minutes
instead of two hours!
• 29 RANGES
BUILT-IN 20 MHZ LOGIC
20 MFD
• RESISTANCE MEASUREMENT To 2000
MEGOHM • 10 AMP RANGE Ac AND De
• CAPACITANCE MEASUREMENT To
• TRANSISTOR GAIN MEASUREMENT
$89
Sendqheckormon~yorderto:.BTAR*TECH Journal,
PO Bof1065, Merchantville NJ 0810~.NJ add 7%.
COD Ok. CaJI 609/662~1080 offax 609/662-0537.
(All orders add $8 s/hiThank you!)
BECKMAN
CAPT6
DIGITAL TEST METER
JAMMA Test Card
VERSATILE CAPACITANCE
DESIGNED FOR THE GAMES TECHNICIAN
• 24
&
PARTS TESTER
USER RANGES
• TEST CAPACITORS TO
/ The $44 Insurance Policy
PROBE
• RESISTANCE
&
20,000
• DIODES • TRANSISTORS
Check out the entire game wiring system
• LEDs • BATTERIES
before
you plug in that $1000 game board!
609/662-1080
Ordelprepaid (add $4.50 s/h) or COD
$TAR*TECH Journal
PO Box 1065, Merchantville, NJ OB 109
MFD
CONTINUITY
$95
Send Orders to:
STAR*TECH Journal
PO Box 1065, Merchantville, NJ 08109.
Add $8 s/h. NJ add 7%. 609/662-1080