Troubleshooting guide

Cinematronics Vector Monitor Repair Guide v.1.0
Page 26 of 53
FACTORY SERVICE UPGRADES
The following are a list of the recommended factory service upgrades that Cinematronics sent out
to all distributors, and operators who sent in their warranty cards. It is safe to assume that not all
games had these modifications made and you should verify each one as it relates to your game.
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July, 1980
ATTN: Distributors/Operators
RE: High Speed Analog Switch (LF13331) modification
Dear Serviceperson(s):
The Analog switch in Cinematronics monitors can be damaged if the -15 volt supply line reaches
the chip before the +15 volt line. Addition of a 1N914 diode protects against this condition.
Attach the cathode (banded end) of the diode to pin 4 of the Analog Switch socket. Attach the
anode to pin 5. After soldering, clean thoroughly with proper solvent or resin remover solution.
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September 24, 1980
Attn: Distributors/ Operators
Re: DAC-80 Modification
Dear Serviceperson(s):
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, 1/4 watt resistor to underside of board between pins 15 -- and 18, per
follow& diagram; Be sure to sever trace at the indicated location.
Vertical DAC -- IC101
Horizontal DAC -- IC201
This modification does not apply to units equipped with analog switch substitution board.
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September 24, 1980
Attn: Distributors/ Operators
Re: High Voltage Section Regulators
Serviceperson(s):
On older Cinematronics’ monitors incorporating a high voltage cage and associated components, a
substitution may be made for the +18 (7818) and –18 (7918) volt regulators if unavailable.