Jvc XMEX 90 Service Manual

Page 1

XM-EX90

JVB
SERV CE MANUAL

XM-EX90

--- Canada

E ------ Continental Europe
J ------------------------ U.S.A.
- Eastern Europe
Northern Europe
........... Hong Kong
-------- China

US -- Singapore
UT -- Taiwan
-- Other Areas
Contents
Safety Precautions ------------------------------ 1-2 Description of Major ICs ----------------------- 2-15
Importance Admistering point on the safety ----- 1-3 Block Diagrams -------------------------------- 2-16
Important for Laser Products ------------ - 1-4 Schematic Diagrams -------------------------- 2-21
Instructions -------------- . 1-5~34 Printed Circuit Boards . 2-24
Location of Main Part 2-1 Parts List --------------------------------------- 3-1
Removal of Main parts ----------------- - 2-3
Main Adjustment --------------------------------- 2-7
Flow of Functional Operation
Until TOC read -------- 2-9
COPYRIGHT © 1995 VlCTOR COMPANY OF JAPAN, LTD. 0-20709

Jul. 1998

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XM-EX90

t

-Safety Precautions

1. This 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 manufacturers
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 (Q) on the Parts List in the Service Manual. The use of a
substitute replacement 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 five 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, 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.

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 areturn 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 1,500910W resistor paralleled by
a 0.151.: F AC-type capacitor between an exposed

metal part and a known good eanh ground. ?£¥SQL:QA§)TER
Measure the AC voltage across the resistor with the ohms/volts,

AC voltmeter. or more sensitivity)
Move the resistor connection to each exposed metal

part, particularly any exposed metal part having a 0.15MF AC TYPE

return path to the chaSSIs, and measure the AC _"_ Place this
voltage across the resrstor. Now reverse the plug in probe on

the AC outlet and repeat each measurement voltage " M ' each exposed
measured any must not exceed 0.75 V AC (r.m.s.). 15009 10W metal part.

This corresponds to 0.5 mA AC (r.m.s.).
Good earth ground

-Warnan
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.

A CAU'HON Burrs formed during molding may be left over on some parts afthe chassis. Therefore,
pay attention to such burrs in the case of preforming repair of this system.

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PARTS LEST

[ XM-EXQO ]

1.Those parts can not to sent as a rule that has not printed or be displayed l-J
on the parts list.

2. The printed circuit board will be not sent as a rule.

3. Parts are safety assurance parts. When replacing those parts, make sure
to use to specified one.

4. All printed circuit boards and its assemblies are not available as service parts.

Area Suffix
B ------------------------- U.Ki
C ----------------- Canada
E ------ Continental Europe
J ---------------- U.S.A.
EE ------ Eastern Europe
EN -------- Northern Europe
UB ~- -------- Hong Kong
UF -- - China
US ~- Singapore
UT -- ------- Taiwan
U ----------------- Other Areas
- Contents -
General Exploded View and Parts List ....................................................... 3- 2
MD Mechanism Assy and Parts List --------------------------------------------------------- 3- 4
Electrical Parts List
Main P.C.B. ------------------------------------------------------------------------- 3- 6
Front PCB. --------------------------------------------------------------------------------- 3- 8
MD Servo Control P.C.B. -------------------------------------------------------------- 3- 9
Loading Circuit P.C.B. ------------------------------------------------------------------------- 3:1 1
Switch Circuit P.C.B. ------------------------------------------------------------------------ 3-11
Packing And Accessories List ------------------------------------------------------ 3-1 2

XM-EXQO

3-1