Jvc AXA 372 BK Service Manual

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Contents
Safety Precautions ....................... 1-2 Block Diagrams ......................... 1-11
Instruction Book ......................... 1-3 Schematic Diagams ................ Insertion
Description of ICs ........................ m Printed Circuit Boards .............. Insertion
) Disasssembly Proceduers __________________ 1.9 Parts List ..... Separate-volume Insertion

PowerAmpiifierAdjustmentProceduers .. 1-10

No. 20491
Jun. 1994

Page 2

AX-A37ZBK

-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 unless authorized in writing by the manufacturer. Replacement parts must
be identical to those used in the original circuits. Services 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 manufacture of responsibility
for personal injury 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 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 shading on the schematics and by (A) on the Parts
List in the Service Manual. The use of a substitute repalcement which does not have the
same safety characteristics as the recommended replacement parts 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 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 currnet 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,
contorl 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.

0 Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester",
measure the leakage current from each exposed metal parts 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 0.5mA 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. Connect a 1,5000 10 W
resistor paralleled by a 0.15 ,uF AC-type capacitor between an exposed metal part and a
known good earth ground.

AC VOLTMETER

Measure the AC volta e across the resistor -
with the AC voltmeter. g E giggfollgoo. . _
Move the resistor connection to each exposed 0 °_ 0' "0'9 59"""""fl
metal part, particularly any exposed metal part
having a return path to the chassis,. and 0.15/(FACTYPE
meausre the AC voltage across the resistor. -fl-
Now, reverse the plug in the AC outlet and P'afhis
repeat each measurement. Any voltage M- Eggheeggosed
measured must not exceed 0.75 VAC (r.m.s.). 1500910W metal part.
This corresponds to 0.5 mA AC (r.m.s.). Good earth ground

--Warning

1. This equipment has been 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.

3. Repairs must be made in accordance with the relevant safety standards.
4. It is essential that safety critical components are replaced by approved parts.
5. If mains voltage selector is provided, check setting for local voltage.

1-2 (No. 20491)

Page 22

_A_X-A3728K

A item Pan Number Part Name Qty Description Area
. 33 QMF51EZv2ROJiBS FUSE 1 F001 (TZLOAIZSOV) BS
A QMFSiEZ-ZRO FUSE 1 F001 (T20A1250v1 EF
A QMF51E2»ZRO FUSE 1 F001 (TZLDA/ZSOV) EN
A QMF51E2.2R0 FUSE 1 F001 (T2.0A/250V) G
A QMF51E2-4ROJ1 FUSE 1 F001 (T4.0A/250v1 U
A QMF51E2-4ROJ1 FUSE 1 F001 (T4.0A/250V) UT
39 E3075720o1 FASTENER 1
4o E407512001 BRACKET I
A 41 QMF51EZ-2R0 FUSE 1 F002 U
A QMF51E2-2R0 FUSE 1 F002 UT
42 808992-001 STAY BRACKET 1
43 E26753-003 METAL COVER 1
44 351660-004 SPECIALSCREW 4
45 E306305092 SPACER z
46 ExooBooOSNzos SPACER 1 UPPER
47 Ex0020010R10510 SPACER 2 SIDE
48 E203192002 REAR PANEL 1 BS
E208192001 REAR PANEL 1 EF
908192-001 REAR PANEL 1 EN
E203192001 REAR PANEL 1 G
908192-003 REAR PANEL 1 U
E20819Z-003 REAR PANEL 1 UT
- E300522043 RATING LABEL I UT
» 300522-043 RATING LABEL 1 UT
49 E408091001 GROUNDTERMINAL 1
50 E73273-003 SPECIALSCREW 7
A 51 QMP55307008585 POWERCORD 1 35
A QMP3900-200 POWERCORD 1 EF
A QMP3900-200 POWERCORD 1 EN
A QMP3900»200 POWERCORD 1 G
A QMP7520»200 POWERCORD 1 U
A QMP7520»200 POWER CORD 1 UT
A 52 QHS3771-1OBBS P.W.BoARD STOPPER 1 as
A QHS3771-108 CORD STOPPER 1 EF
A QHS3771-108 CORD STOPPER 1 EN
A QHS3771-108 CORD STOPPER 1 G
A QHss771-1oa CORDSTOPPER 1 U
A 01153771408 CORD STOPPER 1 UT
53 E306233-002 PROTECTSHEET 1 35
5305233002 PROTECT SHEET 1 EF
E306233-002 PROTECT SHEET 1 EN
E306233-002 PROTECT SHEET 1 U
806233-002 PROTECT SHEET 1 UT
54 E306805134 SPACER
55 5408396001 SWITCH BRACKET
56 E408446001 SHIELD PLATE
57 SBSG3008CC SCREW
58 E67000-005 CAUTION LABEL
59 E48729009 PLASTIC RIVET
. E61029-005 NUMBER LABEL 1
- QZL1007001 BEAB LABEL 1 as
. QZL1031-101 LABEL 1 EF
» E700270o1 LABEL 1 EN
- E407s19031 FTz LABEL 1 G
- E408450094 LABEL 1 Except Um
A : Safety Parts
The Marks for Designated Areas
BS the U.K. EF ContinentalEurope EN Scandinavia
G ..... Germany U Universal Type UT Taiwan

NO mark indicates all area.

274 (No. 20491)