Daewoo CMC-518X, Service Manual

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Safety Check
Care should be taken while servicing this analog color display because of the high voltages used in the deflection
circuits. These voltages are exposed in such areas as the associated flyback and yoke circuits.
Fire & Shock Hazard
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Insert an isolation transformer between the analog color display and AC power line before servicing chassis.
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In servicing, pay attention to original lead dress especially in the high voltage circuit. If a short circuit is found,
replace all parts which have been overheated as a result of the short circuit.
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All the protective devices must be reinstalled per original design.
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Soldering must be inspected for possible cold solder points, frayed leads, damaged insulation, solder splashes or
sharp solder points. Be certain to remove all foreign materials.
Implosion Protection
Picture tube in this monitor employs integral implosion protection system, but care should be taken to avoid damage
and scratching during installation.
Use only same type replacement picture tubes.
X-Radiation
CAUTION: No modifications of any circuit should be attempted. Service work should only be performed after
you are thoroughly familiar with all of the following safety check and servicing guidelines.
IMPORTANT SAFETY NOTICE : There are special components used in analog color display, which are
important for safety. These parts are shaded on the schematic diagram
and on the replacement parts list. It is essential that these critical parts
should be replaced with manufacturer's specified parts to prevent X-
radiation, shock, fire or other hazards. Do not modify the original design
without getting a written permission from DAEWOO ELECTRONICS CO.
or this will void the original parts and labor warranty.
WARNING : The only potential source of X-Radiation is the picture tube. However when the high voltage circuitry
is operating properly, there is no possibility of an X-Radiation problem. The basic precaution which
must be exercised is to keep the high voltage at the following factory recommended level.
NOTE : It is important to use an accurate, periodically calibrated high voltage meter.
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To measure the high voltage, use a high-impedance high-voltage meter.
Connect(-) to chassis and (+) to the CRT anode button.
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Turn the Contrast & Brightness control fully counterclockwise.
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Measure the high voltage. The high voltage meter should indicate the following factory re-
commended level.
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If the upper meter indication exceeds the maximum level, immediate service is required to
prevent the possibility of premature component failure.
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To prevent X-Radiation possibility, it is essential to use the specified picture tube.
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The nominal high voltage is 25.5KV or below, and must not exceed 29KV at zero beam current
at rated voltage.
SAFETY PRECAUTIONS
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