Star Tech Journal

~Bally/Midway Ram-
page Rolling Video
Video Monitor
Capacitor Types
Matt J. Mccullar
Forum Fair Arcade
Arlington, Texas
Bruce Jellison
Automatic Vending & Games
Bangor, Maine
PROBLEM
PROBLEM
Recently I was working on a Rampage whose
picture continually rolled either up or down,
depending on where the vertical hold pot
was set. Adjusting the pot would slow down
the rolling, but not stop it. For some reason
the monitor would not lock onto the picture
and hold it steady.
Regarding James Beck's article on Monitor
Width Size Change in the January issue of
STARnECH JoumaL If the original cap is
replaced with a general replacement type
such as a polyester, it will usually fail in a
short time due to dielectric heating
SOLUTION
The replacement must be an equivelent
polypropylene type designed for high a-c
current and low dissipation factor. I got my
replacements direct from Wells Gardner.
They have a minimum order policy so you
must order several.
SOLUTION
My first thought was a bad vertical hold pot,
but eventually I looked down at the com-
~'puter assembly and noticed that its video
output connector was seated cock-eyed in
its socket. I pushed it back in and the
monitor zoomed in and locked on the picture
perfectly! Apparently the loose socket was
still making contact with the color signals,
but the vertical sync signal on the very end
of the connector no longer reached the pin.
Since this has happened on more than a
couple occasions, anytime I find a monitor
with a rolling picture I check the video cable
from the computer to the monitor.
000
NOTE
Sprague makes a 'type 715P Orange Drop
thatis suitable. I have found few distributors
that stock this series however, so it is
usually a special order. By the way I have
only found the .15 value in former Williams
Moon Patrols.
Rowe Hot Line
Phonos, MBAs
Please make the following correction
in last month's Journal concerning
the Rowe Hot Line. The Hot Line
printed in the Journal is for products
built in Rowe Grand Rapids only and
includes the coin-operated phono-
graph and the bill changers. All other
tech assistance specifically on vend-
ing should be called into Whippany.