Jvc AX A442BK Service Manual

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AX~A44$TN
AXAMZBK

AX-A441 TN
MODEL No. AX'A4423K

Contents

Safety Precaution ................. 1-2 Bfiock Diagram .................. 1-12
instruction Book .................. 1.3 Connection Diagram .............. 1-13
Sntemai Block Diags'am of 1c: ...... mo Printed Circuit Board (E51006?) 1-14
Power Ampfifier Printed Circuit Board ............ insertion
Adjustment Procedures ........ 1-30 Schematic Diagramselock Diagram Msertion
Disagsem bly Procedures ............ 1-H Parts List ........................ insertion
No. 20234
Feb 1 991

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AX~A441TN E
AX-AMZBK i

~- Safety Precautions

l. The design of this produci contains special hardware and many circuits and components
specially for safety puroosesv For consinued protection, no changes should be made to she
original design unless authorized in writing by the manufacturer. Replacement parts must
be identical to those used in the original circuits. Services should be oerformed 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 manufacturers warranty and will further relieve the manufacture of responsibility
for personal iniury or property damage resulting therefrom,

3. Many electrical and mechanical parts in the products have special safety/«related
characteristics. These characteristics are often not evident from visual inspection. no: 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 9am List of Service Manual. Electrical components
having such 1features are identified by shading on the schematics and by i 53} or: she larts
List in the Service Manual. Yhe use of a substitute repalcement which does not have the
same safety characteristics as the recommended replacement parts shows-131': the Parts List of
Service Manual may create shock, fire. or other hazards.

4. Fhe 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 ancilor sharp
edges for the prevention of electric shock and fire hazard. When service is required, she
original lead routing and dress should be observed, and it should be confirmed that they
have been returned to normal, after res-assembling.

S. Leakage currnet check (Electrical shock hazard testing)
After res-assembling the produce, always perform ars isolation check on the exposeo metal
parts of the product {antenna terminals, knobs, metal cabinet, screw heads, headphone ack,
contorl shafts, etc.) to be sure the product is safe to operate without danger of eiectricaé
shock.
Do not use a line isolation transformer during this check.

:1

0 Plug the AC line cord directly into she AC outlet. using a -eakage Current Tester"
measure the leakage current r'rom each exposed metal parts of the cabinet, particulariiy
any exposed metal part having a return path to the chassis, to a known good earrh
ground. Any leakage current must not exceed OVSmA AC (isms).

0 Alternate check method
Plug rhe AC line cord directly into the AC outlet. use an AC voltmeter having, £008
ohms per volt or more sensitivity in the following manner. Connect a 1,5009 30 W
resistor paralleled by a 0.15 ,uF AC-type capacitor between an exposed metal part and a
known good earth ground. AC VQUMETER
Measure the AC voltage across the resistor E (Having «.936
with the AC voltmeter. ohms/volts. . .
Move the resistor connection to each exposed 0 mm mséww')

metal part, particularly any exposed metal part E
having a return path to the chassis, and 3.1sgrAc TYPE
meausre the AC voltage across the resistor. Hi .-

. ?lece shifi
Now. reverse the plug in the AC outlet and '5' 90? m
repeat each measurement. Any voltage (500920! eacnzexpised
measured must not exceed 0.7SVAC (Ln-is). mm 93
This corresponds to 0.5 mA AC (r.m.s.). 6°06 earth Ground

-~ Warning

1:. This equipment has 5oeen designed and manufactured to meet international safety standards.

2. it is the legal responsibility of the repairer to ensure that these safety standards are
maintained.

. Repairs must be made in accordance with the relevant safety standards.
. lt is essential that safety critical components are replaced by aporoved parts.
5. if mains voltage selector 5:; provided, check setting for local voltage.

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2 {No. 20234}