JVC MX-KC4 User manual

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.MB350
2005/4
COMPACT COMPONENT SYSTEM
MB35020054MX-KC4
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27
FM MODE
FM /AM
AUX
SLEEP
STANDBY/ON
CD 1 CD 2 CD 3
SOUND
MODE
RHYTHM AX FADE
MUTING
VOLUME
PROGRAM/RANDOM REPEAT
TAPE
A
CD
TAPE
B
REMOTE CONTROL
CA-MXKC4SP-MXKC4 SP-MXKC4
Area suffix
J ---------------------------- U.S.A.
C ------------------------- Canada

1-2 (No.MB350)
SPECIFICATION
Design and specifications are subject to change without notice.
Amplifier Output Power 180 W per channel, min. RMS, driven into 6 Ωat
1kHz, with no more than 10% total harmonic distortion
Input Sensitivity/Impedance (1 kHz) AUX IN:400 mV/50 kΩ
Speaker terminals 6 - 16 Ω
Phones 32 Ω- 1 kΩ
15 mW/ch output into 32 Ω
Cassette Deck Section Frequency Response : Type l (NORMAL) 63 Hz - 12 500 Hz
Wow And Flutter 0.15% (WRMS)
CD Player CD Capacity 3 CDs
Dynamic Range 85 dB
Signal-To-Noise Ratio 85 dB
Wow And Flutter Unmeasurable
Tuner FM Tuner 87.5 MHz - 108.0 MHz
AM Tuner 530 kHz - 1 710 kHz
Unit Dimensions 270 mm ×306 mm ×456 mm (W/H/D)
(10-11/16" ×12-1/16" ×18")
Mass Approx. 8.6 kg (19.0 lbs)
Speaker Specifications (each unit)
SP-MXKC4 Type 3-way bass-reflex type
Speaker Unit Woofer: 16 cm (6-5/16") cone ×1
Mid: 5cm (2") cone ×1
Tweeter: 2 cm (13/16") dome ×1
Power Handling Capacity 180 W
Impedance 6 Ω
Frequency Range 45 Hz - 22 000 Hz
Sound pressure level 87 dB/W·m
Dimensions 266 mm ×333 mm ×241 mm (W/H/D)
(10-1/2" ×13-1/8" ×9-1/2")
Mass Approx. 3.9 kg (8.6 lbs)
Power Specifications Power Requirements AC 120 V , 60 Hz
Power Consumption 150 W (power on mode)
22 W (in Standby mode)

(No.MB350)1-3
SECTION 1
PRECAUTION
1.1 Safety Precautions
(1) This design of this product contains special hardware and
many circuits and components specially for safety purpos-
es. 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 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 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 characteris-
tics are often not evident from visual inspection nor can the
protection afforded by them necessarily be obtained by us-
ing replacement components rated for higher voltage, watt-
age, etc. Replacement parts which have these special
safety characteristics are identified in the Parts List of Ser-
vice Manual. Electrical components having such features
are identified by shading on the schematics and by ( ) on
the Parts List in the Service Manual. The use of a substitute
replacement which does not have the same safety charac-
teristics 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 reassem-
bling.
(5) Leakage shock hazard testing
After reassembling the product, always perform an isola-
tion check on the exposed metal parts of the product (an-
tenna 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.
• 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, particular-
ly any exposed metal part having a return path to the
chassis, to a known good earth ground. Any leakage cur-
rent 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, 1,000Ωper volt or more sensitivity
in the following manner. Connect a 1,500Ω10W resistor
paralleled by a 0.15µF AC-type capacitor between an ex-
posed metal part and a known good earth ground.
Measure the AC voltage across the resistor with the AC
voltmeter.
Move the resistor connection to each exposed metal
part, particularly any exposed metal part having a return
path to the chassis, and measure the AC voltage across
the resistor. Now, reverse the plug in the AC outlet and
repeat each measurement. Voltage measured any must
not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5
mA AC (r.m.s.).
1.2 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.
1.3 Caution
Burrs formed during molding may be left over on some parts
of the chassis.
Therefore, pay attention to such burrs in the case of pre-
forming repair of this system.
1.4 Critical parts for safety
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 ( )
and ICP ( ) or identified by the " " 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.
(This regulation dose not Except the J and C version)
Good earth ground
Place this
probe on
each exposed
metal part.
AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
1500 10W
0.15 F AC TYPE

1-4 (No.MB350)
1.5 Preventing static electricity
Electrostatic discharge (ESD), which occurs when static electricity stored in the body, fabric, etc. is discharged, can destroy the laser
diode in the traverse unit (optical pickup). Take care to prevent this when performing repairs.
1.5.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as laser products.
Be careful to use proper grounding in the area where repairs are being performed.
(1) Ground the workbench
Ground the workbench by laying conductive material (such as a conductive sheet) or an iron plate over it before placing the
traverse unit (optical pickup) on it.
(2) Ground yourself
Use an anti-static wrist strap to release any static electricity built up in your body.
(3) Handling the optical pickup
• In order to maintain quality during transport and before installation, both sides of the laser diode on the replacement optical
pickup are shorted. After replacement, return the shorted parts to their original condition.
(Refer to the text.)
• Do not use a tester to check the condition of the laser diode in the optical pickup. The tester's internal power source can easily
destroy the laser diode.
1.6 Handling the traverse unit (optical pickup)
(1) Do not subject the traverse unit (optical pickup) to strong shocks, as it is a sensitive, complex unit.
(2) Cut off the shorted part of the flexible cable using nippers, etc. after replacing the optical pickup. For specific details, refer to the
replacement procedure in the text. Remove the anti-static pin when replacing the traverse unit. Be careful not to take too long a
time when attaching it to the connector.
(3) Handle the flexible cable carefully as it may break when subjected to strong force.
(4) I t is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.
1.7 Attention when traverse unit is decomposed
*Please refer to "Disassembly method" in the text for the pickup unit.
• Apply solder to the short land sections before the flexible wire is disconnected from the connecto on the servo board. (If the flexible
wire is disconnected without applying solder, the pickup may be destroyed by static electricity.)
• In the assembly, be sure to remove solder from the short land sections after connecting the flexible wire.
1M
Conductive material
(conductive sheet) or iron palate
(caption)
Anti-static wrist strap
Soldering
Flexible cable
CD changer
unit

(No.MB350)1-5
1.8 Importance administering point on the safety
Caution: For continued protection against risk of
fire, replace only with same type 3.5A/125V for
F901 and 1.6A/250V for F902. This symbol
specifies type of fast operating fuse.
Precaution: Pour eviter risques de feux, remplacez
le fusible de surete de F901 comme le meme type
que 3.5A/125V et F902 que 1.6A/250V .
Ce sont des fusibles suretes qui functionnes rapide.
^

1-6 (No.MB350)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe PRECAUTION.

(No.MB350)1-7
SECTION 3
DISASSEMBLY
3.1 Main body
3.1.1 Removing the metal cover/ rear cover
(See Fig.1 to 5)
(1) Remove the four screws Aon the back of the body.
(2) Remove the six screws Bon the back of the body.
(3) Remove the four screws Cand the two screws Don both
sides of the body.
(4) Move the metal covers in the direction of the arrow with
pulling them sideways, and release two joints aand six
joints b.
Fig.1
Fig.2
A
Rear cover
A
B
BB
Metal cover

1-8 (No.MB350)
Fig.3
Fig.4
Fig.5
C
D
Front panel assembly Metal cover
C
D
Front panel assembly
Metal cover
b
a
b
Metal cover

(No.MB350)1-9
3.1.2 Removing the CD fitting
(See Fig.6 to 8)
• Prior to performing the following procedure, remove the metal
cover/ rear cover.
Caution:
For protecting the CD fitting from damage, remove it before de-
taching the CD changer mechanism unit.
(1) Push STANDBY/ON key to turn on the power.
(2) Push CD tray eject key.
(3) Move the CD fitting in the direction of the arrow to release
two joints dof the CD tray.
(4) Push STANDBY/ON key to close the tray.
3.1.3 Removing the CD fitting
(See Fig.7 to 9)
[How to eject the CD tray without turning on the power]
• Prior to performing the following procedure, remove the metal
cover/ rear cover.
(1) Turn the loading pulley gear on the bottom of the CD
changer mechanism unit (part e) as shown in the figure to
move the CD tray frontward.
(2) Move the CD fitting in the direction of the arrow to release
two joints d.
(3) Push and close the CD tray. Fig.6
Fig.7
CD tray eject key
STANDBY / ON key
CD fitting
CD changer mechanism unit
Front panel assembly
d
d
CD fitting
CD tray

1-10 (No.MB350)
Fig.8
Fig.9
CD tray
CD tray eject key
STANDBY / ON key
CD changer mechanism unit
Front panel assembly
e
Main board
CD changer mechanism unit
Loading pullygear

(No.MB350)1-11
3.1.4 Removing the CD changer mechanism unit
(See Fig.10 to 14)
• Prior to performing the following procedure, remove the metal
cover/ rear cover and the CD fitting.
(1) From the bottom of the CD changer mechanism unit, dis-
connect the wire from connector CN401, CN402 and
CN205 on the main board.
(2) Disconnect the card wire from connector CN403, CN201
and CN601 on the main board.
(3) From the back of the body, remove the four screws Eat-
taching the CD changer mechanism unit.
(4) From the back of the body, remove the four screws Fat-
taching the CD changer mechanism unit.
(5) Pulling the rear panel backward, move the CD changer
mechanism unit in the direction of the arrow and remove.
Fig.10
Fig.11
CN402
Main board
CN401
CN205
CD changer mechanism unit
CN403
CN201
CN601
Main board
CD changer mechanism unit
Rear panel

1-12 (No.MB350)
Fig.12
Fig.13
Fig.14
E
E
Rear panel
F
CD changer mechanism unit
Front panel assembly Rear panel
F
CD changer mechanism unit
Front panel assembly
Rear panel

(No.MB350)1-13
3.1.5 Removing the power board
(See Fig.15 to 19)
• Prior to performing the following procedure, remove the metal
cover/ rear cover, the CD fitting and the CD changer mecha-
nism unit.
(1) Disconnect the wire from connector CN903 and CN202 on
the power board.
(2) Disconnect the card wire from connector CW601 on the
power board.
(3) From the back of the body, remove the four screws Gand
the three screws Hattaching the power board.
(4) Release the two tabs ffrom the notch of the rear panel.
Move the power board in the direction of the arrow and re-
move frontward.
(5) From the bottom of the power board, remove the four
screws Jattaching the heat sink.
(6) Remove the two screws Kattaching the heat sink.
Fig.15
Fig.16
CN903 CN202
CW601
Rear panel Power board
G
G
H
Rear panel

1-14 (No.MB350)
Fig.17
Fig.18
Fig.19
Raer panel
f
Heat sink Power board
J
J
Heat sink
Power board
K
Heat sink
Power board

(No.MB350)1-15
3.1.6 Removing the transformer board
(See Fig.20 to 23)
• Prior to performing the following procedure, remove the metal
cover/ rear cover, the CD fitting and the CD changer mecha-
nism unit.
(1) Disconnect the wire from connector CN903 and CN202 on
the power board.
(2) From the back of the body, remove the four screws Lat-
taching the rear panel.
(3) Remove the cord clamp in the direction of the arrow.
(4) From the base chassis, remove the four screws Mattach-
ing the transformer.
(5) If necessary, unsolder the power cord and the wire extend-
ing from the power transformer assembly.
Fig.20
Fig.21
Fig.22
Fig.23
CN903 CN202
Rear panel Power board
L
Rear panel
Transformer board
Cord clamp
Base chassis
MM
Transformer
Transformer board

1-16 (No.MB350)
3.1.7 Removing the front panel assembly
(See Fig.24 to 27)
• Prior to performing the following procedure, remove the metal
cover, the CD fitting and the CD changer mechanism unit.
(1) Disconnect the wire from connector CN202 on the power
board.
(2) Disconnect the earth wire connected to the main base
chassis.
(3) From the bottom of the body, remove the screw Nattaching
the front panel assembly.
(4) From each side of the body, remove the two screws Pat-
taching the front panel assembly.
(5) Release joints gon each side of the body using a screw-
driver. Remove the front panel assembly frontward.
Fig.24
Fig.25
Fig.26
Fig.27
CN202
Rear panel Power board
Front panel assembly
Earth wire
N
PP
g
Front panel assembly
Side panel (L) Side panel (R)

(No.MB350)1-17
3.1.8 Removing the LCD board, CD tray eject switch board, REC select switch board and Operation board
(See Fig.28 , 29)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Pull out the volume knob on the front panel assembly.
(2) Remove the twenty-six screws Qattaching the LCD board,
CD tray eject switch board, REC select switch board and
Operation board.
Fig.28
Fig.29
3.1.9 Removing the cassette mechanism assembly
(See Fig.30)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the six screws Rattaching the cassette mecha-
nism assembly.
Fig.30
Volume knob
Front panel assembly
Q
Q
Q
Q
Q
Q
Q
CD tray eject
switch board LCD board REC select
switch board
Operation board
R
R
Cassette mechanism assembly
RR

1-18 (No.MB350)
3.1.10 Removing the main board
(See Fig.31 to 33)
• Prior to performing the following procedure, remove the metal
cover/ rear cover, the CD fitting and the CD changer mecha-
nism unit.
Caution:
Before disconnecting the card wire from connector CN701 on
the main board and the CD pickup board, make sure to solder
the short-circuit point on the CD pickup board. If you do not fol-
low this instruction, the pickup may be damaged.
(1) Disconnect the wire from connector CW3 on the motor
board under the main board.
(2) From the bottom of the CD changer mechanism unit, re-
move the four screws Tattaching the main board.
(3) Move the main board as shown in Fig.32 and disconnect
the wire from the connector on the CD mechanism board.
(4) Solder the short-circuit point on the CD pickup board and
disconnect the card wire from the CD pickup board.
Caution:
When reattaching the main board, make sure to connect the
card wire to connector CN701 on the main board and the CD
pickup board before unsoldering the short-circuit point. Fig.31
Fig.32
Fig.33
TT
CN701 CD pick up
board CD mechanism
assembly
Main board
Motor board
CW3
Main board
Motor board
CW3 Short-circuit point
CD changer
mechanism unit
CD mechanism
assembly
CD pickup board
Short-circuit point
Card wire

(No.MB350)1-19
3.1.11 Removing the CD changer mechanism assembly
(See Fig.34 to 35)
• Also remove the CD changer unit.
(1) Turn the CD changer mechanism cover base and remove
the screws dconnecting the unit to the CD changer mech-
anism assembly.
(2) Removing four screws eretaining the CD mechanism hold-
er assembly.
Caution:
When replacing the CD changer mechanism assembly, be
sure not to mistake the positions of the silver color and copper
color spring.
Fig.34
Fig.35
d
CD changer
unit
e ( Green color )
e ( Red color )
e ( Green color )
e ( Red color )
CD changer
mechanism
assembly

1-20 (No.MB350)
3.1.12 Removing the CD pickup
(See Fig.36)
• Prior to performing the following procedures, 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 fwide open, push the section g
in the direction of the arrow to remove the shaft, and then
remove the CD pickup.
Fig.36
3.1.13 Replacing the loading motor and rotor belt of the CD changer
(See Fig .37)
• Prior to performing the following procedures, remove the top
cover.
• Also open the CD changer tray.
(1) Remove the two screws Lretaining the CD changer tray
loading motor.
(2) Remove the two screws Mretaining the gear plate and take
it out, after remove the rotor belt from the pulley.
Fig.37
3.1.14 Replacing the CD turn table and removing the motor
(See Fig.38 )
• Prior to performing the following procedures, remove the top
cover.
• Also remove the CD changer unit.
(1) Remove the one screws retaining the CD (Turn table).
(2) Remove the two screws retaining the stopper brackets on
both sides of the CD changer unit.
(3) Remove the stopper brackets from both sides of the CD
changer unit.
(4) Pull out the CD tray from the CD changer unit, all the way
and lift the tray to remove.
(5) Remove the gear and after push out the tray motor locker
and pull out the tray motor from the CD tray.
Fig.38
g
f
CD pickup
Shaft
M
L
Motor locker
Turn table motor
Obligue gea
r