3
20MR10
SAFETY NOTICE
Many electrical and mechanical parts in television
recevers have special
safety-related
characteristics.
These
characteristics
are often not
evident
from visual
inspection, nor can protection afforded by them be
necessarily
increased
byusing
replacement
components
rated for higher voltage,
wattageand etc.
Replacement parts which have these special safety
characteristics are identified in this manual; electrical
components
havingsuch features are
identified
by " "
and shaded areas in the Replacement Parts Lists and
Schematic Diagrams.
IMPORTANT SER VICE SAFETY PRECAUTION
(Continued)
1. Inspect all lead dress to make certain that leads are
not pinchedor that hardwareis not lodgedbetween
the chassis and other metal parts in the receiver.
2. Inspect all protectivedevices such as non-metallic
control knobs, insulating materials, cabinet backs,
adjustment and compartment covers or shields,
isolation resistor-capacity networks, mechanical
insulatorsand etc.
3. To
be sure that no shock hazard exists, check for
leakage currentin the following manner.
Plug the AC cord directly into a 120 volt AC outlet,
(Do not use an isolation transformer for this test).
Using two clip leads, connect a 1.5k ohm, 10 watt
resistor paralleled by a 0.15µF capacitor in series
with all exposed metal cabinet parts and a known
earth ground,such as electrical conduitor electrical
ground connected to earth ground.
Use an AC voltmeter having with 5000 ohm per volt,
or higher, sensitivity to measure the AC voltage drop
across the resistor.
For continued protection, replacement parts must be
identical
to those used in the
original
circuit.The use of
substitute
replacement
parts
which
do not have
the
same
safety characteristics as the factory recommended
replacement
parts shown in this service manual, may
create shock, fire,
X-radiation
or other hazards.
BEFORE RETURNING THE RECEIVER
(Fire Shock Hazard)
Before returning the receiver to the user, perform
the following safety checks.
Connectthe resistorconnection to all
exposed
metal
parts having a returnto the chassis (antenna, metal
cabinet, screw heads, knobs and control shafts,
escutcheon and etc.) and measure the AC voltage
drop across the resistor.
AII checks must be repeated with the AC line cord
plug connection reversed. (If necessary, a non-
polarized adapter plug must be used only for the
purposeof
completing
these check.)
Any
current
measured
must
not
exceed
0.5 milliamp.
Any measurements not within the limits outlined
above indicate of a potential shock hazard and
corrective
action
mustbe taken before
returning
the
instrument to the customer.
1.5k ohm
10W
0.15 F
TEST PR OBE
CONNECT TO
KNOWN EARTH
GROUND
TO EXPOSED
METAL PARTS
&
!
