Star Tech Journal

Wells Gardner 19K 7901 Cold-Solder Area~
Frank 'The Crank" Seninsky
Alpha-Omega Amusements & Sales
Edison, New Jersey
In addition to the very well done article WG
19K 7901 Intermittent Fix, (J an'89
STAR'4-TECH Journal), there is an additional
area on the Wells Gardner monitors where
cold-solder problems have been the cause of
much downtime.
PROBLEM
Cold solder joints on Rl05, (thermistor,
located on the bottom left comer of the
K7000 Color Monitor Schematic Diagram),
will cause arcing to the monitor chassis just
the same as when the linearity coil (L2) has
a cold solder connection. The arcing will
bum a hole in the PCB and shut down the
monitor.
SOLUTION
I suggest you first check the solder connec-
tions on Rl 05 and resolder. If you're too late,
then first repair all the burnt traces, replace
Rl 05, and check D23 and D24 (which have
also been sometimes found bad). Your
monitor should then be ready to go.
RE: WILLIAMS BUMPERS
I have additional info to report on my article,
For further information, call or write myself
or Morris DeCandia, Senior Engineer, at
Alpha-Omega Amusements & Sales, 6 Sut-
ton Place, Edison, NJ 0881 7. 201 /287-
4990.
Sharp 19" Monitor
Retrace Lines
Ritchie Khodadadi
Atari Games Corporation
Milpitas, California
PROBLEM
Poor picture with retrace lines and no con-
trol over the screen adjustment.
SOLUTION
Replace R602 with a wire wound resistor.
Value= 10 ohms@ l/2w.
WUliams High Speed Jet Bumper Problem,
(Dec'88 STAR*TECH Journal). Chuck
Bleich, Manager of Engineering Department
for Pinball, of Williams called me after read-
ing my article on High Speed. He let me
know, (inaniceway-he'sagreatguy!), that
Williams did correct the omission of the
protection diodes on the schematic and they
were on the schematics of Williams' next
games; Road Kings and MUlionaire.
Murphy's Law #1012