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SAFETY PRECAUTION
1. The design of this product contains special hardware
many circuits and components specially for safety
purposes.
For continued protection, no change
should be made to the original design unless autho¬
rized in writing by the manufacturer. Replacement
parts must be identical to those used in the original
circuits. Service should be performed by qualified
personnel only.
2. Alterations of the design or circuitry of receiver
should not be made. Any design alterations or
additions will void the manufacturer's warranty and
will further relieve the manufacturer of responsi¬
bility for personal injury or property damage
resulting therefrom.
3. Many electrical and mechanical parts in monitor
sets
have
special safety related characteristics.
These characteristics are often not evident from
visual inspection nor can the protection afforded
by them necessarily be obtained by using replace¬
ment components rated for higher voltage, wattage,
etc. Replacement parts which have these special
safety characteristics are identified in the part list
of Service manual. Electrical components having
such features are identified by shading on the
schematics and by
on the parts list in Service
manual. The use of a substitute replacement which
does not have the same safety characteristics as
the recommended replacement part shown in the
parts list in Service manual may create shock, fire
or other hazards.
4. If any repair has been made to the chassis it is
recommended that the power supply be checked
or adjusted (see ADJUSTMENT OF A1 POWER
SUPPLY).
5. The high voltage applied to the picture tube must
conform with that specified in Service manual.
Excessive high voltage can cause an increase in
X-ray emission arcing and possible component
damage therefore operation under excessive high
voltage conditions should be kept to a minimum
or should be prevented. If severe arcing occurs;
remove the AC power immediately and determine
the cause by visual inspection (incorrect installation
cracked
or melted high voltage harness,
poor
soldering etc). To maintain the proper minimum
level of soft X-ray emission components in the high
voltage circuitry including the picture tube must
be the exact replacements or alternative provided
by the manufacturer of the complete product.
6. Do not check high voltage by drawing an arc.
Use high voltage meter or a high voltage probe
with a VTVM. Discharge the picture tube before
attempting meter connection, by connecting a clip
lead to the ground frame and connecting the other
end of the lead through a 10Kn2W resistor to the
anode button.
7. When service is required, observe the original lead
dress. Extra precautions should be given to assure
correct lead dress in the high voltage circuit area.
Where a short circuit has occured, those compo¬
nents that indicate evidence of overheating should
be replace. Always use the manufacturer's replace¬
ment components.
8. ISOLATION CHECK
(SAFETY FOR ELECTRICAL SHOCK
HAZARD)
After re-assembling the Product, always perform
an isolation check on the exposed metal parts of
the cabinet CD' — subminiature connectors, video
phono jacks, metal cabinets, screwheads, sound
phono jack, control shafts, etc) to be sure the pro¬
duct is safe to operate without danger of electrical
shock.
1)
Dielectric Strength Test
The isolation between the AC primary circuit
and a metal parts exposed to the user parti¬
cularly any exposed metal part having a return
path to the chassis should withstand a voltage
of 1,100V AC (r.m.s.) for a period of one
second. This method of test requires a test
equipment not generally found in the service
trade.
2)
Leakage Current Check
Plug the AC line cord directly into the AC
outlet (do not use a line isolation transformer
during this check). Using a "Leakage Current
Tester" measure the leakage current from each
exposed metal part of the cabinet particularly
any exposed metal part having return path to
the chasis to a know good earth ground (water
pipe, etc). Any leakage current must not
exceed 0.7mA.
2
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