1.PRODUCT SAFETY SERVICING GUIDELINES FOR COLOR TELEVISION RECEIVERS
CAUTION : Do not attempt to modify this product in any way.GRAPHIC SYMBOLS :
Unau-thorized modifications will not only void the warranty, butThe lightning flash with arrowhead symbol,
may lead to your being liable for any resulting property damagewithin an equilateral triangle, is intended to
or user injury. Service work should be performed only after youalert the service personnel to the presence of
are thoroughly familiar with all of the following safety checksuninsulated dangerous voltage that may be
and servicing guide-lines. To do otherwise, increases the risk ofof sufficiency magnitude to constitute a riskof
potential hazards and injury to the user.electric shock.
SAFETY CHECKS
After the original service problem has been corrected, a checkThe exclamation point within an equilateral
should be made of the following:triangle is intended to alert the service perso-
nnel to the presence of important safety
SUBJECT : FIRE & SHOCK HAZARDinformation in service literature.
1. Be sure that all components are positioned in such a way as
to avoid possibility of adjacent component shorts.Fuse symbol is printed on pcb adjacent to the
This is especially important on those chassis which arefuse, with RISK OF FIRE REPLACE FUSE
transported to and from the repair shop.AS MARKED . The symbol is explained in the
2. Never release a repair unless all protective devices such asservice manual with the following wording or
insulators, barriers, covers, shields, strain relief, and otherequivalent.
hardware have been reinstalled per original design.
3. Soldering must be inspected to discover possible cold solderCAUTION :FOR CONTINUED PROTECTION AGAINST
joints, frayed leads, damaged insulation (including A.C. cord),FIRE HAZARD, REPLACE ONLY WITH SAME TYPE (6.3A,
solder splashes or sharp solder points. Be certain to remove125V) and
all loose foreign particials. ATTENTION: AFIN D ASSU UNE PROTECTION
4. Check for physical evidence of damage or deterioration toPERMANENTE CONTRE LES RISQUES D INCENDIE,
parts and components, and replace if necessary followREMPLACER UNIQUE-MENT PAR UN FUSIBLE DE MEME
original layout, lead length and dress.TYPE ET DE 6.3A, 125V .
5. No leads or components should touch a receiving tube or a
resistor rated at 1 watt or more. Lead tension aroundSUBJECT : X-RADIATION
protruding metal surfaces must be avoided.
6. All critical components such as fuses, flameproof resistors,1.Be sure procedures and instructions to all service
capacitors, etc. must be replaced with exact factory types.personnel cover the subject of X-rays in current T.V.
Do not use replacement components other than thosereceivers is the picture tube. However, this tube does not
specified or make unrecommended circuit modifications.emit X-rays when the high voltage is at the factory
7. After re-assembly of the set always perform an A.C. leakagespecified level. The proper value is given in the appli-
test on all exposed metallic parts of the cabinet, (the channelcable schematic. Operation at higher voltages may cause
selector knob, antenna terminals, handle and screws) to bea failure of the picture tube or high voltage supply and,
sure the set is safe to operate without danger of electricalunder certain circumstances, may produce radiation in
shock. Do not use a line isolation transformer during this test. excess of desirable levels.
Use an A.C. voltmeter, having 5000 ohms per volt or more2.Only factory specified C.R.T. anode connectors must be
sensitivity, in the following manner : connect a 1500 ohm 10used. Degaussing shields also serve as X-ray shield in
watt resistor, paralleled by a 15 mfd. 150V A.C. typecolor sets. Always re-install them.
capacitor between a known good earth ground (9water pipe,3.It is essential that the serviceman has available an
conduit, etc.) and the exposed metallic parts, one at a time.accurate and reliable high voltage meter. The calibration of
Measure the A.C. voltage across the combination of 1500the meter should be checked periodically against a
ohm resistor and 0.15 MFD capacitor. Reverse the A.C. plugreference standard. Such as the one available at your
and repeat A.C. voltage measurements for each exposeddistributor.
metallic part. Voltage measured must not exceed 0.75 volts4.When the high voltage circuitry is operating properly there
R.M.S. This corresponds to 0.5 milliamp A.C. Any valueis no possibility of an X-radiation problem. Every time a
exceeding this limit constitutes a potential shock hazard andcolor chassis is serviced, the brightness should be run up
must be corrected immediately.and down while monitoring the high voltage with a meter to
be certain that the high voltage does not exceed the
specified value and that it is regulating correctly. We
AC VOLT METER
suggest that you and your service organization review test
procedures so that voltage regulation is always checked
as a standard servicing procedure. And that the high
voltage reading be recorded on each customer s invoice.
5.When troubleshooting and making test measurements in a
receiver with a problem of excessive high voltage, avoid
being unnecessarily close to the picture tube and the high
0.15 ?Fvoltage compartment. Do not operate the chassis longer
Good earth groundthan is necessary to locate the cause of excessive voltage.
such as a water
1500 OHMPlace thes probe6.Refer to HV, B+ and Shutdown adjustment procedures
pipe, conduit, etc.
on each exposed
10 WATTdescribed in the appropriate schematic and
metallic part
diagrams(where used).
FIG 1
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ACEC
