19L-M100, CL19M10
19L-M100S, 20ML10
IMPORTANT SERVICE SAFETY PRECAUTION
e Service work should be performed only by qualified service technicians who are thoroughly
familiar with all safety checks and the servicing guidelines which follow:
WARNINGX-RADIATION AND HIGH VOLTAGE LIMITS
1. For continued safety, no modification of any circuit1. Be sure all service personnel are aware of the
should be attempted.procedures and instructions covering X-radiation.
2. Disconnect AC power before servicing.The only potential source of X-ray in current solid
3. Semiconductor heat sinks are potential shockstate TV receivers is the picture tube. However, the
hazards when the chassis is operating.picture tube does not emit measurable X-Ray
4. The chassis in this receiver has two ground systemsradiation, if the high voltage is as specified in the
which are separated by insulating material. The non-"High Voltage Check" instructions.
isolated (hot) ground system is for the B+ voltageIt is only when high voltage is excessive that X-
regulator circuit and the horizontal output circuit. radiation is capable of penetrating the shell of theThe
isolated ground system is for the low B+ DC voltagespicture tube including the lead in the glass material.
and the secondary circuit of the high voltageThe important precaution is to keep the high voltage
transformer.below the maximum level specified.
To prevent electrical shock use an isolation2. It is essential that servicemen have available at all
transformer between the line cord and powertimes an accurate high voltage meter.
receptacle, when servicing this chassis.The calibration of this meter should be checked
periodically.
CAUTION : FOR CONTINUED3. High voltage should always be kept at the rated value
PROTECTION AGAINST A-no higher. Operation at higher voltages may cause
RISK OF FIRE, REPLACEa failure of the picture tube or high voltage circuitry
ONLY WITH SAME TYPE 4A-and;also, under certain conditions, may produce
4A 125V
125V FUSE.radiation in exceeding of desirable levels.
4. When the high voltage regulator is operating properly
there is no possibility of an X-radiation problem.
SERVICING OF HIGH VOLTAGE SYSTEM
Every time a color chassis is serviced, the brightness
AND PICTURE TUBE
should be tested while monitoring the high voltage
with a meter to be certain that the high voltage does
When servicing the high voltage system,
not exceed the specified value and that it is regulating
remove the static charge by connecting a
correctly.
10k ohm resistor in series with an insulated
5. Do not use a picture tube other than that specified
wire (such as a test probe) between the pic-or make unrecommended circuit modifications to the
ture tube ground and the anode lead. (AChigh voltage circuitry.
6. When troubleshooting and taking test measurements
line cord should be disconnected from AC
on a receiver with excessive high voltage, avoid being
outlet.)
unnecessarily close to the receiver.
1. Picture tube in this receiver employs integralDo not operate the receiver longer than is necessary
implosion protection.to locate the cause of excessive voltage.
2. Replace with tube of the same type number for
continued safety.
3. Do not lift picture tube by the neck.
4. Handle the picture tube only when wearing
shatterproof goggles and after discharging the high
voltage anode completely.
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ACEC
