13VT-L100/150
13VT-CL10
IMPORTANT SERVICE SAFETY PRECAUTION
Service work should be performed only by qualified service technicians who are thoroughly
familiar with all safety checks and servicing guidelines which follow:
WARNINGX-RADIATION AND HIGH VOLTAGE LIMITS
1. For continued safety, no modification of an1.y circuitBe sure all service personnel are aware of the
should be attempted.procedures and instructions covering X-radiation. The
2. Disconnect AC power before servicing.only potential source of X-ray in current solid state TV
3. Semiconductor heat sinks are potential shock hazardsreceivers is the picture tube. However, the picture tube
when the chassis is operating.does not emit measurable X-Ray radiation if the high
4. The chassis in this receiver has two ground systemsvoltage is as specified in the "High Voltage Check"
which are separated by insulation material. The non-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.Theradiation is capable of penetrating the shell of the
isolated ground system is for the low B+ DC voltagespicture tube including the lead in glass material. The
and the secondary circuit of the high voltageimportant precaution is to keep the high voltage below
transformer.the maximum level specified.
To prevent electrical shock use an isolation2. It is essential that servicepersonel have available at
transformer between the line cord and powerall times 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 a
RISKOF FIRE, REPLACEfailure of the picture tube or high voltage circuitry
ONLY WITH SAME TYPE 4A-and;also, under certain conditions, may produce
125V FUSE.radiation that exceeds specifications.4A 125V
4. When the high voltage regulator is operating properly
SERVICING OF HIGH VOLTAGE SYSTEM AND
there is no possibility of an X-radiation problem. Every
PICTURE TUBEtime a color chassis is serviced, the brightness
should be tested while monitoring the high voltage
When servicing the high voltage system, re-with a meter to be certain that the high voltage does
move the static charge by connecting a 10knot exceed the specified value and that it is regulating
ohm resistor in series with an insulated wirecorrectly.
(such as a test probe) between the picture5. Do not use a picture tube other than that specified or
tube ground and the anode lead. (AC linemake unrecommended circuit modifications to the high
voltage circuitry.
cord should be disconnected from AC out-6. When trouble shooting and taking test measurements
let.)
on a receiver with excessive high voltage, avoid being
1. Note that the picture tube in this receiver employsunnecessarily close to the receiver.
integral implosion protection.Do not operate the receiver longer than is necessary
2. Replace with tube of the same type number forto locate the cause of excessive voltage.
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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