Jvc RX 550 VBK Service Manual

Page 2

RX-550VBK
RX-SSOVLBK

Safety Precautions

1. The design of this product contains special hardware and

many circuits and components specially for safety pur-
poses.
For continued protection, no changes should be made to
the original design unless 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 or additions
will void the manufacturers warranty and will further
relieve the manufacturer of responsibility for personal
injury or property damage resulting therefrom.

3. Many electrical and mechanical parts in the product
have special safety-related characteristics. These charac-
teristics are often not evident from visual inspection nor
can the protection afforded by them necessarily be ob~
tained 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 the Service Manual. Electrical components
having such features are identified by snading on the
schematics and by l .5. l on the Parts List in the Service
Manual. The use of a substitute repiacement which does
not have the same safety characteristics as the recom-
mended replacement part shown in the Parts List of
the 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 sepa~
rated 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
the they have been returned to normal. after re-assembl~

ing.

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 product is safe to operate without danger of

electrical shock.

Do not use a line isolation transformer during this check.

r 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.l.

' 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 9
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 voltmeter.
Move the resistor connection to each exposed metal
part. particularly any exposed metal part having a
return path to the chassis, and measure the AC
voltage across the resistor. Now, reverse the plug in
the AC outlet and repeat each measurement. Any
voltage measured must not exceed 0.75 V ACfr.m.s.l.
This corresponds to 0.5 mA AC lr.m.s.l.

r- AC VOLTMETER
C721 lHaving 1000 ohms/volt.

or more SBnSlYlVllYJ

! o is.r ac rvpr

fl i _,,_. 7* ; Pl l o

, l i i . ace tus pro e
I l.- , L_L.~W..L __, on each exposed
U isooii tow metal part.

Good earth ground

fl

l
1 CHECK THE VULTAGE SELECTOR'S SETTING
: (Except for U.$.A.. Canada, Australia. 0.x. and Continental Europe)

lBefore inserting the power plug. please check that the voltage selector's setting corresponds with
Ithe line voltage in your area. If it doesn't be sure to reset. the voltage selector before operating

l this equip-exit.

'The voltage selector lay be located on the rear or bottom of the unit, or underneath the Platter.

lflUTlON : Before setting the voltage selector to the proper voltage, disconnect. the power plug.

l~2 [No.2976l

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