I
IJWells Gardner 4600
Black Level Control
David Dickson
Louque Vending Company Inc.
Perry. Florida
PROBLEM
Over the past few months I have had many
of these monitors come into the shop with
the same problem. The monitor will be oper-
ating, but no picture.
•
SOLUTION
Replace the black level control. It is VR201,
a 1.5k ohm
potentiometer located on
the interface board. I have had a hard time
finding an exact replacement for this pot, so
I have been usingWico #36-0011. This is a
lk ohm pot, but it works fine in this circuit.
NOTE
On some monitors the black level control will
be mounted on the front of the board, and on
some it will be mounted on the back. If you
will install the new pot on the back of the
board it will make it easier to adjust the
brightness in the future.
Atari 720° Joystick
Control Update
Al Vernon
Field Service Tech
Atari Games Corporation
Milpitas. California
PROBLEM
Players motion object does not respond to
the joystick.
SOLUTION
Ifby changing the optical coupler P.C.B. on
the joystick controller does not correct the
problem - replace the leta at Loe 7F on the
C.P.U. board. Atari part #137304-2002.
NOTE
In some cases a bad leta will cause a lock-up
condition or a 6502 communication error
(failure) in the self test. If you suspect a bad
leta, remove it from its socket and reboot.
The game should then come up and pass the
self test.
For more information, please call Atari
Games at 408/ 434-3950.
Nintendo Sanyo Monitor Capacitor Failure
Sam Cross
Godwin Distributing Company
North Little Rock, Arkansas
.
MONITOR TYPE
Nintendo Sanyo Monitor 20-EZV (R-C)
SYMPTOM
A new capacitor to replace: In addition to
C407, a 10 microfarad at 160vdc capacitor
with radial leads baking open and causing
vertical foldover on one side of the screen,
another capacitor is going bad, causing bad
picture brightness.
SOLUTION
This capacitor is C4 72, a 100 microfarad at
160vdc capacitor with radial leads. It is
located near the flyback transformer. Re-
place to restore good picture quality.