Star Tech Journal

Issue: 1980-November - Vol 2 Issue 9

S~R-TECH _ _ _ _ _ _ _ _ _ _ 3
Atari "Missile Command" Cocktail Modification
WARNING! There may be a hazard of electrical
shock at the black posistor just above the focus
adjustment knob at the right-hand side of the
monitor chasses (as viewed from the rear). To
avoid this potential hazard, the posistor should
be relocated away from the focus control in the
existing hole as shown. Use the same screw
(screw will form its own threads).
Please take care to ensure that this
modification is implemented as soon as possible.
This affects Missile Command Cocktails from
S/N 001-449, 453-455, 462-464, 468 and 681.
RELOCATE AT THIS
POSITION
FOCUS ADJUSTMENT KNOB
Midway "Galaxian" Problems and Solutions
QUICK REFERENCE OF PROBLEMS+ SOLUTIONS
SYMPTOM
No Video
Aliens Break Up
Picture Breaks Up
Galaxip, Letters Break Up
Stars Flash or are Missing
Blows Fuses
Lines in Picture (Colored or Black)
Lines through Attackers
Bad Ram 2 on Screen
Bad Rom on Screen
Tilts Itself (Resets)
Garbage on Screen
No Sound
POSSIBLE SOLUTION
Power Supply
2101
2101
2101
74LS164
Power Supply
27LS00,93411,82S16*
27LS00,93411,82S16*
74C245**
Rom Card
Rom Card
Rom Card
1877, .1 uf Cap. (LM 377)
LOCATION
4F/5F
4F/5F
4F/5F
1A/1 B
1 N-1T
1 N-1T
9B/5J**
7F-7L
7F-7L
7F-7L
11A, C26
The table shows~
of the most common problems
and probable trouble areas.
Use this table for quick fixes
and reference to problem
areas only.
*All the same type of part
located at 1 N-1 T with heat
sinks glued on.
**7 4C245 is a Bi-Directional
bus driver. Some boards
have 2-821 6's as bus
drivers. In this case, the
problem probably lies
somewhere else.
4 _ _ _ _ _ _ _ _ _ _ SlA~TECH
Cinematronics
Monitor Service Notes and Modifications
"Rip Off" Test Pattern
There exists a test pattern in your Rip Off Game that is enabled
by switch 7 on the dip switch located in position E2 of the main
CPU board (see page 2-2 of manual).
The test pattern is for alignment purposes and should be
adjusted to fill the playfield as shown below:
DD
[I]
[I]
To control the width of the display, adjust potentiometer R209
on the monitor. R109 adjusts the height of the picture.
Adjust potentiometers R102 and R202 so that all vectors (line
segments) neatly intersect. R202 controls horizontal line
lengths. R102 adjusts the length of all vertical lines. To center
the picture, adjust the magnetic positioning tabs on the yoke
housing.
Contrast Adjustment on "Rip Off"
There may be too great an intensity difference between the fuel
cells and the ships if your Rip Off game is positioned in a low
ambient light environment. This contrast problem can be solved
by the insertion of a variable resistor in the intensity network.
Replace R1 O (5.6K) with a SK ohm potentiometer. This will
allow the fuel cells to be adjusted to an acceptable level.
DAC-80 Modification
In order to assure prolonged reliability of IC1 (LF13331) on
Cinematronics' monitors, a current limiting resistor is being
added to the outputs of the horizontal and vertical DAC's. This is
a recommended retrofit for all existing systems.
Add 1 each 820 ohm, ¼ watt resistor to underside of board
between pins 15 and 18, per following diagram. Be sure to sever
trace at the indicated location.
Horizontal DAC
IC 201
Vertical DAC
IC 101
This modification does not apply to units equipped with analog
switch substitution board.

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