Jvc AX 550BK Service Manual

Page 1

AX-550BK

JVB
SERVICE MANUAL

Contents

Safety Precautions.
Front Panel .
Operation.
Specifications
Block Diagram .. ..
Removal Procedures ................................................... 1A

Adjustment Procedures

Schematic Diagram... Insertion
Connection Diagram Insertion
Parts List ................ Separate Volume Insertion

Internal Block Diagrams of iCs ................................... 1»9

No. 2973
Feb 1987

Page 2

AX-5SOBK

Safety Precautions

1. The design of this product contains special hardward

and many circuits and components specially for safety
purposes.
For continued protection, no changes should be made
to the original design unless authorized in writing by
the manufacturer, Replacement pans 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 addi-
tions will void the manufacturer's warranty and will
further relieve the manufacturer of responsibility for
personal injury or property damage resulting thereform.

3. Many electrical and mechanical pans in the product
have special safety-related characteristics. These char~
acteristics 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 indentified
in the Parts List of Service Manual. Electrical compon-
ents having such features are identified by shading on
the schematics and by (A) on the Parts List in the Ser-
vice 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 of 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 separat-
ed from live parts, high temperature parts, moving parts
and/or sharp edges or 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 iso-

lation check on the exposed metal pars of the product

(antenna terminals, knobs, metal cabinet, screw heads,

headphone iack, 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.

0 Plug the AC line cord directly into the AC outlet. Us-
ing 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.).

0 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. Use an AC line
cord directly into the AC outlet. Connect a 1,500 .(2
10 W resistor paralleld by a 0.15 F ACtype capaci-
tor 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 re-
turn 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 AC (rtm.s.). This
corresponds to 0.5 mA AC (r.m.s.).

AC VOLTMETER
(HAVING 10009/V,
OR MORE SENSITIVITY)
O 0
0.15m: AC-TYPE
-i I-
PLACE THIS PROBE
VW 4 ON EACH EXPOSED
1500!.) 10W METAL PART
GOODEARTH GROUND

CHECK THE VOLTAGE SELECTOR'S SETTING

(Except for U.S.A., Canada, Australia, U.K. and Continental Europe.)

Before inserting the power plug, please check that the voltage selectors setting corresponds with the line voltage in
your area. If it doesnt, be sure to reset the voltage selector before this equipment.

The voltage selector may be located on the rear or bottom of the unit, or underneath the platter.

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

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