Star Tech Journal

SNK/Tradewest Video
Interference Solution
Matt J. Mccullar
Forum Fair Arcade
Arlington, Texas
SUBJECT
Does your Ikari Warriors, Guerilla War or
other S.N.K./Tradewest game have a very
strong pattern of interference on the screen?
Here is a possible cause and cure.
CAUSE
Figure 1 displays the video connector for the
monitor and the pins for the incoming signal
lines. Two ground pins - 3 and 7 - are
available, but Tradewest uses only pin 3. I
have found on many occasions that the
single ground wire was installed in pin 4,
which is not connected to anything else!
GRN
DRIVE
See Figure 2; see the gap between the video
sockets? That's where pin 4 is! With no
ground reference to the monitor, the video
signals pick up all kind of Radio frequency
Interference (RFI).
SOLUTION
The cure? A sharp, pointed instrument will
pop the black ground wire out of pin 4's hole.
It then slides easily into the empty pin ~
socket and locks into place. This shoult.
eliminate the interference.
RED
DRIVE
CONNECTOR
FROM GAME
-Ji :t 1 + ~ :th Jr Ji i-1
GND
8LU
GAN
RED
HDAIZ
VERT VEJIT
VERT
VERT
HORIZ
CENTERING SIZE. HOLD DAMPING RASTEII RASTER
POI,
SHl,T
Figure 1 Input Connectors
SCREEN
Figure 2 Video Inputs