Jvc XLM 403 BK Service Manual

Page 1

XL-M4OSBK

JVG ,
SERV CE MANUAL

MODEL NoXL-M403 BK

(XL-M403BK)
l lfiOMl-ACT
DIGITAL AUDIO
Contents
Safety Precaution -------------------- Operation check by each switch ------------------------- 1-36
Importnat for Laser Products Flow of Functional Operation
Instruction Book ................... Until TOC is Read ........................................ 1-37
Description of Major LSls ---------------------------------- 1-21 Trouble shooting --------------- 1-38
Internal Block Diagram of Others Ids" Schematic Diagram .. mlnsertion
Internal Connections for the FL Display Tube ''''' 1»28 Block Diagrams --------------------- "insertion
Disassembly Procedures- Printed Circuit Boardm Insertion
Adjustment Procedures» Connection Diagrams~ mlnsertion
Maintenance of Laser Pickup ------------------------------ 1-33 Exploded View of Assemblies and
Replacement of Laser Pickup ----- Application points for Grease mlnsertion
Initial Operation of Mechanism u Parts List --------------------------- Separate-Volume Insertion
No. 20161

Mar. 1 990

Page 2

XL-M403BK

-Safety Precautions

l. 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. Service should be per-
formed 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 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 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 pans 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 sub-
stitute 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 separated from

live parts, high temperature parts, moving parts and/or sharp edges for the preventionof 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.

Leakage current check (Electrical shock hazard testing)

After reassembling 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 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 sensi-
tivity in the following manner. Connect a 1,500 O 10W resistor paralleled by a 0.15 uF AC-type capacitor be-
tween an exposed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC VOLTMETER
AC voltmeter. @ (Having 1000 ohmsivolt.

, '- , or more sensitivity.)

Move the resistor connection to each exposed metal

part, particularly any exposed metal part having a Lj-
return path to the chassis, and measure the AC volt~ 5: ac "PE
age across the resistor. Now, reverse the plug in the Place this probe
AC outlet and repeat each measurement. Any voltage ' 4w on each exposed
measured must not exceed 0.75 VAC (r.m.s.). This 1 isoon tow metal part.
corresponds to 0.5 mA AC (r.m.s.).

9

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 settinglfor local voltage.

l-Z(Nm20|61)