Jvc MXK 7 Service Manual

Page 1

MX- K7

JVC

SERVICE MANUAL

COMPACT COMPONENT SYSTEM

MX-K7

SP-DSK7 SP-MXK7 CA-MXK7 SP-MXK7 SP-DSK7

@iEé USE [50%

DIGITAL AUDIO Recordable ReWritabIe

Area Suffix
J ------------------- U.S.A.

Contents

Safety precautions ----------------------- 1-2 Flow of functional

Important for laser products - operation until TOC read ------- 1-20
Preventing static electricity ------------- 1-4 Maintenance of laser pickup - 1-21
Disassembly method --------------------- 1-5 Replacement of laser pickup 1-21
Adjustment method ----------------------- 1-18 Description of major ICs ----------------- 1-22

No.20958

COPYRIGHT (6 2001 VICTOR COMPANY OF JAPAN, LTD.
May. 2001

Page 2

MX-K7

-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 (/t\,) 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 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, 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 a return
path to the chassis, to a known good earth ground. Any leakage current must not exceed 0.5mA AC (r.m.s.).

. 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 1,500 Q10W resistor paralleled by a 0.1 51.1 F AC-type capacitor

between an exposed metal part and a known good earth ground. AC VOLTMETER
Measure the AC voltage across the resistor with the AC a (Having1000
voltmeter. ohms/volts,

Move the resistor connection to eachexposed metal part, c more sens'W'W)

particularly any exposed metal part having a return path to
the chassis, and meausre the AC voltage across the resistor. 0'15: AC TYPE

Now, reverse the plug in the AC outlet and repeat each -"| Placehis
measurement. Voltage measured any must not exceed 0.75 V W . ~ gaitheeigosed
AC (r.m.s.). This corresponds to 0.5 mA AC (r.m.s.). 15009 10W metal part.
Good earth ground
- Warning A CAUTION

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.

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

In regard with component parts appearing on the silk-screen printed side (parts side) of the PWB diagrams, the
parts that are printed over with black such as the resistor (-), diode (h) and ICP (Q) or identified by the (N
mark nearby are critical for safety.

When replacing them, be sure to use the parts of the same type and rating as specified by the manufacturer.
(Except the J and C version)

Page 12

MX-K7

I Removing the CD pickup (See Fig.1?) CD pickUP

- Prior to performing the following procedures, fl /
remove the top cover.

- Also remove the CD changer unit.

- Also remove the CD changer mechanism

1.Widen the section f
2.While keeping the section "f" wide open, push the

section g in the direction of the arrow to remove
the shaft, and then remove the CD pickup.

I Replacing the loading motor and belt
of the CD changer tray (See Fig.18)

- Prior to performing the following procedure,
remove the top cover.

1.Pull out the CD changer tray.

2. Remove the belt from the pulley.

3. Remove the two screws "L" retaining the CD
changer tray loading motor.

[Caution] When pushing in the CD changertray, be
sure to lower the CD changer mechanism
assembly by manually turning the UD
cam gear in the direction of the arrow.

/UD cam gear
L

Pulley \llzg:

I Replacing the CD tray rotor belt of the

CD changer, and removing the motor Belt °
(See Fig.19 and 20) O
- Prior to performing the following procedures, 0 0
remove the top cover. 0
- Also remove the CD changer unit. 0

1.Remove the two screws "M" retaining the stopper
brackets on both sides of the CD changer unit.

2. Remove the stopper brackets from both sides of CD changer
the CD changer unit. tray O O

3. Pull out the CD tray from the CD changer unit, all
the way and then lift the tray upward to remove.

4.Turn the CD tray upside down and remove the tray
rotor belt from the pulley. Fig.18

5.Turn the CD tray upside down and disconnect the
card wire from the connector CN605 on the CD
tray rotor motor assembly.

6. Remove the two screws "N" retaining the CD tray
rotor motor, and then remove the CD tray rotor
motor.

4444-
O

/ CD tray
rotor belt

Stopper bracket M ,4 Pulley
CN605 N
Fig.1 9 Fig . 20