JVC UX-S20EN User manual

SERVICE MANUAL
COPYRIGHT © 2006 Victor Company of Japan, Limited No.MB538
2006/7
MICRO COMPONENT SYSTEM
MB53820067
UX-S20EN,UX-S20EV
Lead free solder used in the board (material : Sn-Ag-Cu, melting point : 219 Centigrade)
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
CA-UXS20 SP-UXS20SP-UXS20
Ths UX-S20 is derivative model for Dixon group.

1-2 (No.MB538)
SPECIFICATION
Designs & specifications are subject to change without notice.
Amplifier Section Output Power 25 W per channel, min. RMS, driven into 4 Ωat 1 kHz with no more
than 10% total harmonic distortion. (IEC268-3)
Audio input sensitivity/Impedance (at 1 kHz) AUX: 500 mV/50 kΩ
Speakers Impedance 4 Ω- 16 Ω
Tuner FM tuning range 87.50 MHz - 108.00 MHz
AM (MW) tuning range 522 kHz - 1 629 kHz
CD player Dynamic range 85 dB
Signal-to-noise ratio 85 dB
Wow and flutter Immeasurable
Cassette deck Frequency response Normal (type I) 100 Hz - 10 000 Hz
Wow and flutter 0.35% (WRMS)
General Power requirement AC 230 V , 50 Hz
Power consumption 52 W (at operation)
1.5 W (on standby)
Dimensions (W/H/D) (approx.) 152 mm ×233 mm ×331 mm
Mass (approx.) 4.5 kg
Speaker Section Type Full range, bass-reflex type
Speakers 10 cm cone ×1
Power handling capacity 25 W
Impedance 4 Ω
Frequency range 100 Hz - 15 kHz
Dimensions (W/H/D) (approx.) 152 mm ×233 mm ×188 mm
Mass (approx.) 1.8 kg each

(No.MB538)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.MB538)
1.5 Important for laser products
1.CLASS 1 LASER PRODUCT
2.CAUTION :
(For U.S.A.) Visible and/or invisible class II laser radiation
when open. Do not stare into beam.
(Others) Visible and/or invisible class 1M laser radiation
when open. Do not view directly with optical instruments.
3.CAUTION : Visible and/or invisible laser radiation when
open and inter lock failed or defeated. Avoid direct
exposure to beam.
4.CAUTION : This laser product uses visible and/or invisible
laser radiation and is equipped with safety switches which
prevent emission of radiation when the drawer is open and
the safety interlocks have failed or are defeated. It is
dangerous to defeat the safety switches.
5.CAUTION : If safety switches malfunction, the laser is able
to function.
6.CAUTION : Use of controls, adjustments or performance of
procedures other than those specified here in may result in
hazardous radiation exposure.
REPRODUCTION AND POSITION OF LABELS and PRINT
!Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.
WARNING LABEL and PRINT

(No.MB538)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 Difference point of UX-G4 and UX-S20
(1) Main body color
(2) Main body RDS logo mark
(3) RDS indication of remote control
RDS SEARCH →PTY SEARCH
RDS MODE→PS/PTY/RT
(4) Speaker saran net
SECTION 3
DISASSEMBLY
This service manual does not describe DISASSEMBLY.
SECTION 4
ADJUSTMENT
This service manual does not describe ADJUSTMENT.
SECTION 5
TROUBLESHOOTING
This service manual does not describe TROUBLESHOOTING.

(No.MB538)
Audio/Video Systems Category 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan
Victor Company of Japan, Limited
VPT
Printed in Japan

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.MB371
2005/6
MICRO COMPONENT SYSTEM
MB37120056
UX-G3,UX-G4
Lead free solder used in the board (material : Sn-Ag-Cu, melting point : 219 Centigrade)
TABLE OF CONTENTS
1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
Area suffix
B ------------------------------ U.K.
E ---------- Continental Europe
EN ----------- Northern Europe
EV ------------- Eastern Europe
CA-UXG3 SP-UXG3SP-UXG3
CA-UXG4 SP-UXG4SP-UXG4

1-2 (No.MB371)
SPECIFICATION
Designs & specifications are subject to change without notice.
Amplifier Section Output Power 25 W per channel, min. RMS, driven into 4 Ωat 1 kHz with no more
than 10% total harmonic distortion. (IEC268-3)
Audio input sensitivity/Impedance (at 1 kHz) AUX: 500 mV/50 kΩ
Speakers Impedance 4 Ω- 16 Ω
Tuner FM tuning range 87.50 MHz - 108.00 MHz
AM (MW) tuning range 522 kHz - 1 629 kHz
CD player Dynamic range 85 dB
Signal-to-noise ratio 85 dB
Wow and flutter Immeasurable
Cassette deck Frequency response Normal (type I) 100 Hz - 10 000 Hz
Wow and flutter 0.35% (WRMS)
General Power requirement AC 230 V , 50 Hz
Power consumption 52 W (at operation)
1.5 W (on standby)
Dimensions (W/H/D) (approx.) 152 mm ×233 mm ×331 mm
Mass (approx.) 4.5 kg
Speaker Section Type Full range, bass-reflex type
Speakers 10 cm cone ×1
Power handling capacity 25 W
Impedance 4 Ω
Frequency range 100 Hz - 15 kHz
Dimensions (W/H/D) (approx.) 152 mm ×233 mm ×188 mm
Mass (approx.) 1.8 kg each

(No.MB371)1-3
SECTION 1
PRECAUTIONS
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.MB371)
1.5 Safety Precautions (U.K only)
(1) This design of this product contains special hardware and many circuits and components specially for safety purposes. For con-
tinued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replace-
ment parts must be identical to those used in the original circuits.
(2) Any unauthorised design alterations or additions will void the manufacturer's guarantee; furthermore the manufacturer cannot
accept responsibility for personal injury or property damage resulting therefrom.
(3) Essential safety critical components are identified by ( ) on the Parts List and by shading on the schematics, and must never
be replaced by parts other than those listed in the manual. Please note however that many electrical and mechanical parts in
the product have special safety related characteristics. These characteristics are often not evident from visual inspection. Parts
other than specified by the manufacturer may not have the same safety characteristics as the recommended replacement parts
shown in the Parts List of the Service Manual and 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.
1.5.1 Warning
(1) Service should be performed by qualified personnel only.
(2) This equipment has been designed and manufactured to meet international safety standards.
(3) It is the legal responsibility of the repairer to ensure that these safety standards are maintained.
(4) Repairs must be made in accordance with the relevant safety standards.
(5) It is essential that safety critical components are replaced by approved parts.
(6) 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.

(No.MB371)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

1-6 (No.MB371)
SECTION 3
DISASSEMBLY
3.1 Main body
3.1.1 Removing the front panel assembly
(See Fig.1 to 6)
(1) From the back of the body, remove the two screws A, the
two screws B and the two screws D attaching the front pan-
el assembly.
(2) Remove the six screws E on both sides of the body.
(3) Remove the screw F on the bottom of the body.
(4) Move the front panel assembly in the direction of the arrow
and remove. Disconnect connector CN402, CON801 on
the main board.
Caution:
When reassembling the front panel assembly, fit the right and
left joints a to the notch.
Fig.1
Fig.2
CD mechanism assembly
Rear cover assembly
B
D
A
Front panelh assembly
CD mechanism assembly
Rear cover assembly
E

(No.MB371)1-7
Fig.3
Fig.4
Fig.5
Fig.6
Front panelh assembly
CD mechanism assembly
Rear panel assembly
E
Front panel assembly
Rear panel assembly
F
CD mechanism assembly
Front panel assembly
Rear cover assembly
Joint a
CD mechanism assembly
Front panel assembly
Main board
Rear cover assembly
CN402
CON801

1-8 (No.MB371)
3.1.2 Removing the main board
(See Fig.7, 8)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Disconnect the wire from all connectors on the main board.
(2) Disconnect the wire from the two connectors on the cas-
sette mechanism assembly.
(3) Release the three bands attaching the wire to the main
board.
(4) Remove the two screws G from the front panel assembly.
Release the joint b.
Fig.7
Fig.8
CD mechanism assembly
CD mechanism assembly
Front panel assembly
CN203
CN481
Main board
CN303
CN602
CN301
CN401
CN603
CN103
Main board Band
CD mechanism assembly
Front panel assembl
y
Joint b
G

(No.MB371)1-9
3.1.3 Removing the CD mechanism assembly
(See Fig.9, 10)
• Prior to performing the following procedure, remove the front
panel assembly and the main board.
(1) Remove the three bands attaching the wire.
(2) Disconnect the connector from the CD door switch. Discon-
nect the wire from connector CN603 and CN606 on the CD
mechanism board.
(3) Disconnect the wire soldered on the CD mechanism board.
(4) Remove the three screws H attaching the CD mechanism
assembly.
(5) Release the joints d to remove the CD mechanism assem-
bly from the front panel assembly.
Fig.9
Fig.10
CD mechanism assembly
CD door switch
CD mechanism board
Front panel assembly
CN603 CN606
Band
Band
Band
H
H
H
CD mechanism assembly
Front panel assembly
Joint d
Joint d
CN603,CN606
band
wire

1-10 (No.MB371)
3.1.4 Removing the CD mechanism assembly
(See Fig.11 to 13)
• Prior to performing the following procedure, remove the front
panel assembly, the main board and the CD mechanism as-
sembly.
Caution:
Before disconnecting the card wire from connector CN601 on
the CD mechanism board and from CD pickup board, 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 on the CD motor
board.
(2) Remove the four screws J attaching the CD mechanism
board.
(3) Move the CD mechanism board temporarily as shown in
Fig.12.
(4) Remove the screw K attaching the wire to the CD mecha-
nism.
(5) Solder the short-circuit point on the CD pickup board.
(6) Disconnect the card wire from connector CN601 on the CD
mechanism board.
Caution:
Make sure to unsolder the short-circuit point after reconnecting
the card wire to the CD pickup board and to connector CN601
on the CD mechanism board.
Fig.11
Fig.12
Fig.13
CD mechanism assembly
CD mechanism board
CN601
Wire
J
J
CD mechanism assembly
CD motor board
CD mechanism board
wire
Cord wire
CN601
Short-circuit point
K
Short-circuit point
Card wire
Unsolder
CD pickup board

(No.MB371)1-11
3.1.5 Removing the CD mechanism
(See Fig.14)
• Prior to performing the following procedure, remove the front
panel assembly, the main board, the CD mechanism assembly
and the CD mechanism board.
(1) Remove the four screws M attaching the CD mechanism.
Fig.14
3.1.6 Removing the headphone board/ AUX board
(See Fig.15)
• Prior to performing the following procedure, remove the front
panel assembly, the main board and the CD mechanism as-
sembly.
(1) Remove the screw N attaching the headphone board.
(2) Remove the screw P attaching the AUX board.
Fig.15
CD mechanism assembly
CD mechanism
M
M
Front panel assembly
A
UX board Head phones board
PN

1-12 (No.MB371)
3.1.7 Remove the LCD board
(See Fig.16, 17)
• Prior to performing the following procedure, remove the front
panel assembly, the main board and the CD mechanism as-
sembly.
(1) From the front panel, pull out the volume knob and remove
the nut and the washer.
(2) Remove the twelve screws Q attaching the LCD board.
Fig.16
Fig.17
Front panel assembly
Washer
Volume konb
Nat
Front panel assembly
LCD board
Q
Q
QQ

(No.MB371)1-13
3.1.8 Removing the cassette mechanism assembly
(See Fig.18, 19)
• Prior to performing the following procedure, remove the front
panel assembly and the main board.
(1) Push 'PUSH OPEN' on the front panel to open the cassette
door.
(2) Remove the screw R attaching the bracket of the cassette
mechanism assembly.
(3) Remove the two screws T and the two screws U attaching
the cassette mechanism assembly.
Fig.18
Fig.19
Front panel assembly
Cassette door
PUSH OPEN
Cassette mechaanism assembly
Front panel assembly
Bracket TT
UU
R

1-14 (No.MB371)
3.1.9 Removing the heat sink/power board
(See Fig.20 to 25)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the four screws Y attaching the holder in the pow-
er unit section.
(2) Move the power unit section with the wire from the rear cov-
er temporarily. If necessary, release the band and unsolder
the wire on the power board.
(3) Remove the four screws A' and the two screws B' attaching
the holder.
(4) Remove the three bands on the wire extending from the
power board (part e). Move the holder in the direction of the
arrow to detach from the joint f.
(5) Remove the four screws D' and screw E' attaching the heat
sink.
Fig.20
Fig.21
Rear cover
YY
Y
Y
Power trnsfomer assembly
Power unit section
Rear cover
Power unit section