Product safety servicing guidelines for color
A.C. VOLTMETER
television receivers
CAUTION :Do not attempt to modify this product in any
way. Unauthorized modifications will not only void the
warranty, but may lead to your being liable for any
resulting property damage or user injury.
Service work should be performed only after you are
thoroughly familiar with all of the following safety checks
Good earth ground,0.15?F
and servicing guidelines. To do otherwise, increases theYY
risk of potential hazards and injury to the user.such as the water1500 OHMPlace this probe
pipe, conduit, etc.
on each exposed
10WATTmetal part.
SAFETY CHECKS
After the original service problem has been corrected, a
check should be made of the following:GRAPHIC SYMBOLS :
The lightning flash with arrowhead symbol,
SUBJECT : FIRE & SHOCK HAZARDwithin an equilateral triangle, is intended to
1. Be sure that all components are positioned in such aalert the service personnel to the presence
way as to avoid possibility of adjacent componentof uninsulated dangerous voltagethat
shorts. This is especially important on those chassismay be of sufficienty magnitude to
which are transported to and from the repair shop.constitute a risk of electric shock.
2. Never release a repair unless all protective devicesThe exclamation point within an equilateral
such as insulators, barriers, covers, shields, straintriangle is intended to alert the service
reliefs, and other hardware have been reinstalled per
personnel to the presence of important
original design.
safety information in service literature.
3. Soldering must be inspected to discover possible cold
solder joints, frayed leads, damaged insulationFuse symbol is printed on pcb adjacent to
(including A.C. cord), solder splashes or sharp solderthe fuse, with RISK OF FIRE REPLACE
points. Be certain to remove all loose foreign particals.FUSE AS MARKED . The symbol is
explained in the service manual with the
4. Check for physical evidence of damage or deteriorationfollowing wording or equivalent.
to parts and components, and replace if necessaryCAUTION : FOR CONTINUED PROTECTION AGAINST
follow original layout, lead length and dress.FIRE HAZARD, REPLACE ONLY WITH SAME TYPE 4A,
5. No leads or components should touch a receiving tube125V FUSE and ATTENTION: AFIN DASSU UNE
PROTECTION PERMANENTE CONTRE LES RISQUES
or a resistor rated at 1 watt or more. Lead tension
around protruding metal surfaces must be avoided.D INCENDIE, REMPLACER UNIQUEMENT PAR UN
FUSIBLE DE MEME TYPE ET DE 4A, 125V.
6. All critical components such as fuses, flameproof
resistors, capacitors, etc. must be replaced with exact
SUBJECT : X-RADIATION
factory types. Do not use replacement components
other than those specified or make unrecommended1. Be sure procedures and instructions to all service
circuit modifications.personnel cover the subject of X-rays in current T.V.
receivers is the picture tube. However, this tube does
7. After re-assembly of the set always perform an A.C.not emit X-rays when the high voltage is at the factory
leakage test on all exposed metallic parts of thespecified level. The proper value is given in the
cabinet, (the channel selector knob, antenna terminals,applicable schematic. Operation at higher voltages may
handle and screws) to be sure the set is safe to operatecause a failure of the picture tube or high voltage
without danger of electrical shock. Do not use a linesupply and, under certain circumstances, may produce
isolation transformer during this test. Use an A.C.radiation in excess of desirable levels.
voltmeter, having 5000 ohms per volt or more
sensitivity, in the following manner : connect a 15002. Only factory specified C.R.T. anode connectors must
be used. Degaussing shields also serve as X-ray shield
ohm 10 watt resistor, paralleled by a 15 mfd. 150V A.C.
in color sets. Always re-install them.
type capacitor between a known good earth ground
(9water pipe, conduit, etc.) and the exposed metallic3. It is essential that the serviceman has available an
parts, one at a time. Measure the A.C. voltage acrossaccurate and reliable high voltage meter. The
the combination of 1500 ohm resistor and 0.15 MFDcalibration of the meter should be checked perio -
capacitor. Reverse the A.C. plug and repeat A.C.dically against a reference standard. Such as the one
voltage measurements for each exposed metallic part.available at your distributor.
Voltage measured must not exceed 0.75 volts R.M.S.
This corresponds to 0.5 milliamp A.C. Any value4. When the high voltage circuitry is operating properly
there is no possibility of an X-radiation problem. Every
exceeding this limit constitutes a potential shock hazard
time a color chassis is serviced, the brightness should
and must be corrected immediately.
be run up and down while monitoring the high voltage
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ACEC
