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PC-Y777 B/E/G
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2
~|1| Safety Precautions
1. The design of this product contains special hardware and many circuits and components
specially for safety
purposes. For continued protection, no changes should be made to the original design uniess authorized 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 the product should not be made. Any design alterations of the product
should not be made. Any design alterations or additions will void the manufacturer's warranty and will further
relieve the manufacturer or responsibility for personal injury or property damage resulting therefrom.
3. Many
electrical
and
mechanical
parts in the product
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 replacement components rated for higher voltage, wattage, etc. Replacement parts which
have these special safety characteristics are identified in the Parts List of Service Manual. Electrical components
having such features are identified by (A\) on the schematic diagram and Parts List in Service Manual. The use
of a substitute replacement which does not have the same safety characteristics as the recommended replace-
ment
part shown
in the Parts List in Service Manual may create shock, fire, or other hazards.
4. The leads in the products are routed and dressed with ties, clamps, tubings, barriers and the like to be separated
from live parts, high temperature parts, moving parts and/or sharp edges for the prevention of electric shock
and fire hazard.
When
service is required, the original lead routing and dress should be observed,
and it should be confirmed
that they have been returned to normal, after re-assembling.
5. Leakage current check (Electrical shock hazard testing)
After re-assembling the product, always perform an isolation check on the exposed metal parts of the product
(antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts, etc.) to be sure the pro-
duct is safe to operate without danger of electrical shock.
Do not use a line isolation transformer during this check.
* Plug the AC line cord directly into the AC outlet. Using a 'Leakage Current Tester'', measure the leakage
current from each exposed metal part of the cabinet, particularly any exposed metal part having a return path
to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5 mA AC (r.m.s.).
® Alternate check method
Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having 1,000 ohms per volt or more
sensitivity in the following manner. Connect a 1,500 2 10 W resistor paralleled by a 0.15 uF AC-type capacitor
between an exposed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC
ET
Were
ons cea
voltmeter.
or more sensitivity.)
Move the resistor connection to each exposed metal
o
Sl
part, particularly any exposed metal part having a return
.
0.15 pF AC TYPE
path to the chassis, and measure the AC voltage across
the resistor. Now, reverse the plug in the AC outlet and
'
Blake thiscorebe
repeat each measurement. Any voltage measured must
on each etpcaad
not exceed 0.75 V AC (r.m.s.).
1500 2 10 W
metal part.
This corresponds to 0.5 mA AC (r.m.s.).
Good earth ground
—Warning
. This equipment has been designed and manufactured to meet international safety standards.
. It is the legal responsibility of the repairer to ensure that these safety standards are mainteined.
. Repairs must be made in accordance with the relevant safety standards.
. It is essential that safety critical components are replaced by approved parts.
. If mains voltage selector is provided, check setting for local voltage.
oh
WON
=
(No. 1802)
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