JVC MX-SK1 User manual

SERVICE MANUAL
COPYRIGHT © 2004 VICTOR COMPANY OF JAPAN, LIMITED No.MB207
2004/4
COMPACT COMPONENT SYSTEM
MB20720043
MX-SK1
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-30
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-34
COMPACT
DIGITAL AUDIO
COMPACT
DIGITAL VIDEO
PHONES
ACTIVE
BASS EX.
EJECTEJECT
DISC
SELECT
SELECT
M X - S K 3
COMPACT
DIGITALVIDEO
V
O
L
U
M
E
STANDBY/ON
FMMODE
AUX
SLEEP
FM/AM
VIDEOINTRO
PREV. NEXT
HIGHLIGHT
ONSCREEN
SET
ENTER
RETURN
PBC STILL KEYCONTROL
DISC
1 DISC 2 DISC 3
DISC
REPEAT PROGRAM RANDOM
PROGRAM
CANCEL
SOUND
TURBO
SOUND
MODE
ACTIVE
BASSEX.
TAPE-A
KARAOKE MPX
ECHO
FADE
MUTING
TAPE-B
VOLUME
REMOTE CONTROL
START/STOP
REC
CA-MXSK1SP-MXSK1 SP-MXSK1
EE --------- Russian Federation
Area suffix

1-2 (No.MB207)
SPECIFICATION
Design & specifications are subject to change without notice.
Amplifier section
Output Power MAIN SPEAKERS 64 W per channel min. RMS both channels driven into
6 Ωat 1 kHz with no more than 0.9% total harmonic
distortion.
Audio input sensitivity/Impedance
(Measured at 1 kHz with tape record-
ing signal 300 mV)
AUX 400 mV/50 kΩ
MIC 3 mV/10 kΩ
Tuner
FM tuning range 87.50 MHz to 108.00 MHz
AM tuning range At 9 kHz intervals 531 kHz to 1 710 kHz
At 10 kHz intervals 530 kHz to 1 710 kHz
CD player
CD capacity 3 CDs
Dynamic range 85 dB
Signal-to-noise ratio 90 dB
Wow and flutter Immeasurable
Cassette deck
Frequency response Normal (type I) 50 Hz to 14 000 Hz
Wow and flutter 0.15% (WRMS)
General
Power requirement AC 110 V / AC 127 V / AC 220 V / AC 230 V to AC 240 V (adjustable with the voltage selector)
Power consumption 50 Hz / 60 Hz
100 W (at operation)
20 W (on standby)
Dimensions (approx.) 270 mm x 306 mm x 433.5 mm (W/H/D)
Mass (approx.) 9.2 kg
Speaker Specifications
Type 3-Way 3 Speaker Bass-Reflex (Magnetically-Shielded Type)
Speakers Main woofer 15cm cone x 1
Mid Range 5.0cm cone x 1
Tweeter 2.0cm dome x 1
Power Handling Capacity 80 W
Impedance 6 Ω
Frequency Range 42 Hz to 30 000Hz
Sound Pressure Level 84 dB/W.m
Dimensions (W x H xD) 215mm x 306 mm x 243 mm
Mass 3.4 kg

(No.MB207)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.MB207)
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 CD players.
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 CD pickup unit.
• Apply solder to the short land sections before the flexible wire is disconnected from the connecto on the CD servo board. (If the
flexible wire is disconnected without applying solder, the CD 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

(No.MB207)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

1-6 (No.MB207)
SECTION 3
DISASSEMBLY
3.1 Main body
3.1.1 Removing the metal cover
(See Fig.1~3)
(1) Remove the six screws Aon the back of the main body.
(2) Remove the four screws Bon each side of the body.
(3) Remove the metal cover from the body by lifting the rear
part of the cover.
CAUTION :
Do not break the front panel tab fitted to the metal cover.
Fig.1
Fig.2
Fig.3
A
AA
B
B

(No.MB207)1-7
3.1.2 Removing the CD fitting
(See Fig.4~6)
• Prior to performing the following procedure, remove the metal
cover.
ATTENTION :
Be sure to remove the CD tray fitting before removing the
CD changer unit.
(1) Press the STANDBY button. Press the OPEN/CLOSE but-
ton to eject the CD trey.
(2) Move the CD trey fitting upward and release the joint a.
(3) Press the OPEN/ CLOSE button to insert the tray.
Fig.4
Fig.5
Fig.6
CD tray
STANDBY / ON button
OPEN / CLOSE button
CD tray fitting Joint a
Joint a
CD tray

1-8 (No.MB207)
3.1.3 Removing the CD fitting
(See Fig.5~7)
• How to eject the CD trey without turning on power.
(1) Turn the loading pulley gear marked bfrom the back of
the CD changer unit as shown in Fig.7 and draw the CD
tray toward the front.
(2) Move the CD tray fitting upward and release the joint a.
(3) Push and insert the CD tray manually.
Fig.7
3.1.4 Removing the CD changer unit
(See Fig.8 ~10)
• Prior to performing the following procedure, remove the metal
cover and the CD fitting.
(1) Disconnect the wire from connector CN13 on the main
board.
(2) On the right side of the body, disconnect the card wire from
connector CN651 on the CD board in the bottom of the CD
changer unit.
(3) Remove the four screws Dattaching the CD changer unit
on both sides of the body.
(4) Remove the three screws Eon the back of the body.
(5) Move the CD changer unit in the direction of the arrow with
pulling the rear panel and the front panel assembly out-
ward.
Fig.8
Fig.9
Fig.10
Marked b
Loading pulley gear
D
Front panel assembly
Main borad
(CN13)
Rear panel
CN651
CD changer unit
D
Front panel assembly
Main borad
(CN13)
Rear panel
CN651
CD changer unit
E
E
Rear panel

(No.MB207)1-9
3.1.5 Removing the CD board
(See Fig.11~13)
• Prior to performing the following procedure, remove the metal
cover and the CD changer unit.
Caution :
Before disconnecting the card wire extending from the CD
pickup, make sure to solder the short-circuit point on the CD
pickup(Fig.12 and 13). If you do not follow this instruction,
the CD pickup may be damaged.
(1) Remove the four screws Fattaching the CD board on the
bottom of the CD changer unit.
(2) Turn and move the CD board as shown in Fig.12.
(3) Disconnect the wire from the CD mechanism board.
(4) Solder the short-circuit point on the CD pickup section.
(5) Disconnect the card wire from CN601 on the CD board.
Caution :
When reassembling, unsolder the short-circuit point after con-
necting the card wire to CN601 on the CD board.
Fig.11
Fig.12
Fig.13
CD board
CD mechanism board
CD changer unit
FF
CD mechanisum board
CD board (CN601)
Short round
(Short-circuit)
Pick up Card wire
Short round
(short-circuit)

1-10 (No.MB207)
3.1.6 Removing the front panel assembly
(See Fig.14~16)
• Prior to performing the following procedure, remove the metal
cover and the CD changer unit.
(1) Disconnect the card wire from the connector CN315,
CN316 and CN870 on the main board.
(2) Disconnect the wire from connector CN702 on the speaker
board and remove the band attaching the wire to the main
board.
(3) Disconnect the wire from the connector CN214 on power
transformer board.
(4) Remove the two screws Gattaching the front panel as-
sembly on the bottom of the body.
(5) Remove the two joints dand eon the lower part of the
sides using a screwdriver, and remove the front panel as-
sembly toward the front.
Fig.14
Fig.15
Fig.16
Main board
CN870
Speaker board
CN702
Front panel assembly
CN315
Band
d
CN316
Power transformer board
CN214
Front panel assembly
e
G
Front panel assembly

(No.MB207)1-11
3.1.7 Removing the tuner pack assembly
(See Fig.17~18)
• Prior to performing the following procedure, remove the metal
cover and the CD changer unit.
(1) Disconnect the card wire from the connector CN1 on the
tuner pack assembly on the right side of the body.
(2) Remove the two screws Hon the rear panel on the back
of the body.
Fig.17
Fig.18
Tuner pack
(CN1)
AUX & surround board
Rear panel
HRear panel

1-12 (No.MB207)
3.1.8 Removing the AUX & surround board
(See Fig.19, 20)
• Prior to performing the following procedure, remove the metal
cover and the CD changer unit.
(1) Disconnect the card wire from the connector CN411,
CN711 on the on the AUX & surround board on the right
side of the body.
(2) Remove the screw Jon the rear panel on the back of the
body.
Fig.19
Fig.20
Tuner pack
AUX & surroud board
(CN411)
Rear panel
J
Rear panel

(No.MB207)1-13
3.1.9 Removing the rear panel
(See Fig.21~25)
• Prior to performing the following procedure, remove the metal
cover and the CD changer unit.
(1) Disconnect the wire from the connector CN1 on the tuner
pack assembly on the right side of the body.
(2) Disconnect the wire from the connector CN411, CN711 on
the AUX surround board.
(3) Remove the screw K attaching the rear cover on the back
of the body.
(4) Remove the two screws Lattaching the speaker board,
and the two screws Mattaching the power transformer
board on the back of the body.
(5) Remove the four screws Nattaching the heat sink on the
back of the body.
(6) Remove the screw Pattaching the rear cover on the back
of the body.
(7) Release the two joints f and gon the bottom of the rear
panel using the screw driver, then detach the rear panel
backward.
Reference: The rear panel comes off with the tuner pack
assembly and the AUX surround board.
Fig.21
Fig.22
Fig.23
Fig.24
Fig.25
Tuner pack
(CN1)
AUX & surroud board
(CN411)
Rear panel
KRear panel
Rear cover
N
NP
Rear panel
Heat sink M
L
f
Rear panel
f
Rear panel

1-14 (No.MB207)
3.1.10 Removing the main board / speaker board
(See Fig. 26~29)
• Prior to performing the following procedure, remove the metal
cover and the CD changer unit, the rear panel.
(1) Disconnect the card wire from the connector CN315,
CN316 and CN870 on the main board.
(2) Disconnect the wires from connector CN202 and CN702
on the speaker board. Remove the band attaching the wire
to the main board.
(3) Remove the screw Qattaching the main board and the
screw Rattaching the speaker board.
(4) Move the speaker board in the direction of the arrow to re-
lease from the base chassis at the joint hand the two
joints j.
Reference:
The speaker board comes off with the main board and
the heat sink.
(5) Remove the screw Tand the three screws Uattaching the
heat sink. The heat sink comes off with the heat sink brack-
et.
(6) Detach the main board from connector CN701 on the
speaker board.
Fig.26
Fig.27
Fig.28
Fig.29
Main board
CN316
CN315
CN870
CN702
CN202
Band
Speaker board
Main board
Q
hR
Band
Speaker board
Heat sink
Main board
R
j
j
Speaker board
Heat sink
Main board
Speaker board
Heat sink
T
U
U
CN701

(No.MB207)1-15
3.1.11 Removing the power transformer assembly
(See Fig.30~32)
• Prior to performing the following procedure, remove the metal
cover, and the CD changer unit, the rear panel, the speaker
board.
(1) Disconnect the wire from connector CN21 on the power
transformer board.
(2) Remove the screw A' attaching the power transformer
board on the left side of the body.
(3) Remove the four screws B' attaching the power transform-
er board.
(4) Push the cord stopper upward and remove.
(5) Disconnect the power cord from connector CN250 on the
power transformer board and remove the band.
(6) Remove the power transformer assembly upward.
Fig.30
Fig.31
Fig.32
B'
CN250
CN214
Power transfomer board
Power transfomer assembly
B'
A'
CN214
Power transfomer board
CN250
Power cord stopper
Power cord stopper
Power cord

1-16 (No.MB207)
3.2 Front panel assembly
• Prior to performing the following procedure, remove the metal cover, the CD changer unit and the front panel assembly.
3.2.1 Removing cassette mechanism assembly
(See Fig.33,34)
(1) Remove the eight screws D' attaching the cassette mech-
anism assembly.
3.2.2 Removing the LCD board
(See Fig.34)
(1) Disconnect the card wire from the connector CN880 on the
LCD board.
(2) Remove the nine screws E' attaching the LCD board.
Fig.33
Fig.34
D'D'
D'D'
Cassett mechanism assembly
Front panel assembly
E'
E'
E'
Cassett mechanism assembly
CN880
Swithc board
LCD board

(No.MB207)1-17
3.2.3 Removing the switch board
(See Fig.35,36)
• Prior to performing the following procedure, remove the LCD
board.
(1) Pull out the MIC level knob from the front of the front panel
assembly.
(2) Remove the two screws D' attaching the two wires on the
bottom of the front panel assembly.
(3) Remove the ninteen screws F' attaching the switch board.
(4) Unsolder the wire on the switch board at FW800 point.
Fig.35
Fig.36
Front panel assembly
MIC level knob
F'
F'
D'
F'
F'
D'
Cassette mechanism assembly
Swithc board
Volume board
FW800

1-18 (No.MB207)
3.2.4 Removing the volume board
(See Fig.37,38)
• Prior to performing the following procedure, remove the LCD
board and the switch board.
(1) Pull out the volume knob from the front of the front panel
assembly.
(2) Remove the nut from the front panel assembly.
(3) Release the volume board from the tab and remove.
Fig.37
Fig.38
Front panel assembly
Nut
Volume knob
Volume board
Tab
Tab

(No.MB207)1-19
3.3 CD changer unit
• Prior to performing the following procedure, remove the CD changer unit.
3.3.1 Removing the CD tray
(See Fig.39~45)
(1) Turn the loading pulley gear on the under side of the CD
changer unit in the direction of the arrow and draw the CD
tray toward the front until it stops.
(2) Disconnect the card wire from connector CW2 of the motor
board on the upper side of the CD changer unit.
(3) Push down the two tray stoppers and pull out the CD tray.
Reference:
When reassembling, set each gear as shown in Fig.42 and in-
sert the CD trays as shown in Fig.43.
Fig.39
Fig.40
Fig.41
Fig.42
CD tray
Loading
pulley gear
CLOSE OPEN
CD tray
Tray stoppe
r
Tray stopper
Motor board
CW2
CD Tray

1-20 (No.MB207)
Fig.43
Fig.44
Fig.45
CD tray
Tab
Sensor board
Tray motor
CD tray
mn
Connecto
r
Spacer
m
n