JVC =UX-J55V User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED No.MB057
2003/12
MICRO COMPONENT SYSTEM
MB057200312 UX-J55V
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28
S
P-UXJ55VCA-UXJ55V
S
P-UXJ55V
COMPACT
DIGITAL VIDEO
COMPACT
DIGITAL AUDIO
COMPACT
DIGITALVIDEO
STANDBY/ON
DISPLAY
CLOCK
/TIMER
SLEEP
TREBLE
UP
BASS
CANCELSET
TAPE FM/AM AUX
REPEAT
KARAOKE
RANDOM
AHB
PRO
STILL
MPX
PRGM
RETURN
13
2
4 65
7 98
10 +10
RM-
DIGITAL
ECHO
NEXT
DOWN
PREV.
/SELECT
CD
FM
MODE
REV.
MODE
CD
Area Suffix
US ------------- Singapore
UN ------------------ Asean

1-2 (No.MB057)
SPECIFICATION
Design and specifications are subject to change without notice.
Amplifier Output Power 120 W (60 W + 60 W) at 6 Ω(10% THD)
Audio input sensitivity
/Impedance (at 1 kHz) AUX 400 mV/48 kΩ
Speakers/Impedance 6 Ω- 16 Ω
Tuner FM tuning range 87.50 MHz - 108.00 MHz
AM tuning range AM 10 kHz intervals 530 kHz - 1 710 kHz
AM 9 kHz intervals 531 kHz - 1 710 kHz
CD player Dynamic range 85 dB
Signal-to-noise ratio 90 dB
Wow and flutter Immeasurable
Cassette deck Frequency response Normal (type I) 60 Hz - 14 000 Hz
Wow and flutter 0.15% (WRMS)
Speaker
SP-UXJ55V Speaker units Woofer 12.0 cm cone ×1
Midrange 4.0 cm cone ×1
Tweeter 2.0 cm dome ×1
Impedance 6 Ω
Dimensions (approx.) 160 mm ×285 mm ×181.5 mm (W/H/D)
Mass (approx.) 2.4 kg each
General Power requirement AC 110 V/ 127 V/ 220 V/ 230 V - 240 V , adjustable with the voltage selector, 50 Hz/60 Hz
Power consumption 130 W (at operation)
3.4 W (on standby)
Dimensions (approx.) 490 mm ×286 mm ×323.3 mm (W/H/D)
Mass (approx.) 10.3 kg

(No.MB057)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 expose
d
metal part.
AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)
1500 10W
0.15 F AC TYPE

1-4 (No.MB057)
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 connector CN601 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
CN601 on
mechanism
board
Shorting round
Shorting round
Flexible wire

(No.MB057)1-5
1.8 Important for laser products
1.CLASS 1 LASER PRODUCT
2.DANGER : Invisible laser radiation when open and inter
lock failed or defeated. Avoid direct exposure to beam.
3.CAUTION : There are no serviceable parts inside the
Laser Unit. Do not disassemble the Laser Unit. Replace
the complete Laser Unit if it malfunctions.
4.CAUTION : The compact disc player uses 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 de
feated. 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 herein may result in
hazardous radiation exposure.
REPRODUCTION AND POSITION OF LABEL and PRINT
WARNING LABEL and PRINT
!Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.
Caution label

1-6 (No.MB057)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MB057)1-7
SECTION 3
DISASSEMBLY
3.1 Main body
3.1.1 Removing the metal cover
(See Fig.1~3)
(1) Pull out the MIC volume knob on top of the body.
(2) Remove the six screws Aon the back of the main body.
(3) Remove the two screws Bon each side and remove the
metal cover in the direction of the arrow.
Fig.1
Fig.2
Fig.3
Metal cover
Volume knob
A
A
A
B
B

1-8 (No.MB057)
3.1.2 Removing the rear cover
(See Fig.4)
(1) Remove the two screws Dattaching the rear cover.
Fig.4
D
Rear cove
r

(No.MB057)1-9
3.1.3 Removing the rear panel / fan assembly
(See Fig.5,6)
• Prior to performing the following procedure, remove the metal
cover and the rear cover.
(1) Remove the twelve screws Eattaching the rear panel.
Release the two joints aon the rear side and the two joints
bon each side.
(2) Remove the two screws Fattaching the fan bracket and
release the two joints don the rear panel, and remove.
(3) Disconnect the wire from the connector CN908 on the main
board.
Reference:
The MIC volume board comes off.
3.1.4 Removing the MIC volume board
(See Fig.6)
• Prior to performing the following procedure, remove the metal
cover, the rear cover and the rear panel.
(1) Remove the two screws Gattaching the MIC volume board
on the inside of the rear panel.
(2) Disconnect the wire from connector CN906 on the main
board on the back of the body.
Fig.5
Fig.6
Rear panel
Fan assembly
EE
E
E
E
FE
F
d
d
a
bb
Main board
Mic volum board
CN908
CN906
Rear panel
G

1-10 (No.MB057)
3.1.5 Removing the tuner board
(See Fig.7)
• Prior to performing the following procedure, remove the metal
cover.
(1) Disconnect the card wire from the connector CN1 on the
tuner board.
(2) Remove the two screws Hon the rear side and the screw
Jin the side.
Fig.7
3.1.6 Removing the VCD mechanism assembly
(See Fig.8)
• Prior to performing the following procedure, remove the metal
cover, the rear cover, the rear panel and the tuner board.
(1) Disconnect the card wire from the connector CN903,
CN902 and CN904 on the main board.
(2) Pull the joint ein the direction of the arrow and remove the
VCD mechanism assembly backward while releasing the
joint f.
Fig.8
Tuner board
CN1
H
J
CN902
CN904
CN903
VCD mechanism assembly
Main board
e
e
f

(No.MB057)1-11
3.1.7 Removing the main board / the heat sink board / the speaker board / the vocal cancel board
(See Fig.9~11)
• Prior to performing the following procedure, remove the metal
cover, the rear cover, the rear panel, and the VCD mechanism
assembly.
(1) Remove the two screws Kattaching the main board.
(2) Disconnect the card wire from the connector CN900,
CN901,CN930,CN931 and CN932, and disconnect the
wire from the connector CN907 and CN916,CN917 on the
main board.
(3) Remove the band and disconnect the wire from the
connector CN951 on the power transformer assembly, and
then remove the main board / the heat sink board from the
body.
(4) Release the two joints gof the main board and disconnect
the connector CN944 and CN945 of the heat sink board
from the connector CN912 and CN911 of the main board
respectively, and remove.
(5) Remove the two screws Land the two screws Mattaching
the heat sink.
(6) Remove the screw Nattaching the speaker board.
(7) Disconnect the vocal cancel board from connector CN905
on the main board.
Fig.9
Fig.10
Fig.11
H
g
Main board Power transformer assembly
CN951
CN930
CN916
CN900
CN901
CN917
CN931
CN907
CN932
Band
Main board
CN905
Vocal cancel board
CN944
CN945
CN912
CN911
CN905
Heat sink board
Main board
Vocal cancel board
Speaker board

1-12 (No.MB057)
3.1.8 Removing the power transformer assembly
(See Fig.12)
• Prior to performing the following procedure, remove the metal
cover, the rear cover, the rear panel, the VCD mechanism
assembly and the main board.
(1) Disconnect the power cord from the connector J1000 on
the power transformer assembly.
(2) Remove the four screws P.
Fig.12
Power transformer assembly
J1000
PP

(No.MB057)1-13
3.1.9 Removing the front panel assembly
(See Fig.13,14)
• Prior to performing the following procedure, remove the metal
cover, the rear cover, the rear panel, and the VCD mechanism
assembly.
(1) Remove the two screws Qon each side. Release the two
joints hon the both sides and lift the front panel assembly
to release the joint j.
(2) Disconnect the card wire from the connector CN900,
CN901, CN930, CN931 and CN932 on the main board.
Fig.13
Fig.14
Q
h
Front panel assembly
Q
h
j
Front panel assembly
CN932CN931 CN930
CN900 CN901
Main board

1-14 (No.MB057)
3.1.10 Removing the phones board
(See Fig.15)
• Prior to performing the following procedure, remove the metal
cover, the rear cover, the rear panel, the VCD mechanism
assembly and the front panel assembly.
(1) Disconnect the wire from the connector CN913 on the main
board.
Fig.15
3.1.11 Removing the cassette mechanism assembly
(See Fig.16)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the four screws Rattaching the cassette
mechanism assembly.
Fig.16
Phones board
Mian board
CN907
R
R
Cassette mechanism assembly

(No.MB057)1-15
3.1.12 Removing the switch board
(See Fig.17,18)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the four screws Tattaching the switch board.
(2) Move the switch board in the direction of the arrow to
disconnect the wire from the connector CN762 and the
card wire from the connector CN761.
3.1.13 Remove the LCD board assembly
(See Fig.17)
• Prior to performing the following procedure, remove the front
panel assembly.
(1) Remove the four screws Uattaching the LCD board
assembly.
Fig.17
Fig.18
T
UU
T
Switch board
LCD board assembly
Switch board
CN762 CN761

1-16 (No.MB057)
3.1.14 Removing the control panel assembly
(See Fig.19,20)
• Prior to performing the following procedure, remove the front
panel assembly, the switch board and the LCD board
assembly.
(1) Remove the three screws Yattaching the control panel
assembly.
(2) Release the three joints kand open the cassette door
while pressing the cassette door, and then remove the
control panel assembly in the direction of the arrow.
Fig.19
Fig.20
Y
Y
Cotrol panel assembl
y
k

(No.MB057)1-17
3.1.15 Remiving the control board
(See Fig.21,22)
• Prior to performing the following procedure, remove the front
panel assembly, the switch board, the LCD board assembly
and the control panel assembly.
(1) Pull out the volume knob.
(2) Remove the six screws A’ attaching the control board.
Fig.21
Fig.22
Control panel assembly
Volume knob
A'
A
'
A'
Control board
Control panel assembly

1-18 (No.MB057)
3.1.16 Removing the VCD board / CD servo control board
(See Fig.23~26)
• Prior to performing the following procedure, remove the metal
cover, the rear cover, the rear panel and the VCD mechanism
assembly.
Caution:
Before disconnecting the card wire extending from the CD
pickup, make sure to solder the short-circuit point on the CD
pickup(Fig.25 and 26). If you do not follow this instruction, the
CD pickup may be damaged.
(1) Disconnect the card wire from connector CN101 on the
VCD board on the bottom of the VCD mechanism
assembly.
(2) Remove the four screws B' attaching the board cover.
(3) Disconnect the wire from connector CN801 on the CD ser-
vo control board and the card wire from connector CN606
respectively.
(4) Remove the two screws D' attaching the CD servo control
board and the board bracket.
(5) Move the CD servo control board in the direction of the
arrow to release two joints m.
(6) Turn and move the CD servo control board in the direction
of the arrow.
(7) Solder the short-circuit point on the CD pickup.
(8) Disconnect the card wire from connector CN601 on the CD
servo control board.
Caution:
When reassembling, unsolder the short-circuit point after
connecting the card wire to CN601 on the CD board.
Fig.23
Fig.24
Fig.25
VCD mechanism assembly
Board cover
CN101
B' B'
B'
VCD mechanism assembly
Board bracket
CD servo control board
VCD board
CN801
CN606
m m
D'
D'
CD servo
control board
CN601
Card wire
Short round

(No.MB057)1-19
Fig.26
Card wire
Short round
Pick up board

1-20 (No.MB057)
3.2 Cassette mechanism assembly
3.2.1 Removing the Play/Record & Clear head
(See Fig.1~3)
(1) While moving the trigger arm on the right side of the head
mount in the direction of the arrow, turn the flywheel R
counterclockwise until the head mount comes ahead and
clicks.
(2) The head turns counterclockwise as you turn the flywheel
R counterclockwise (See Fig.2 and 3).
(3) Disconnect the flexible wire from connector CN31 on the
head amplifier & mechanism control board.
(4) Remove the spring from the back of the head.
(5) Loosen the azimuth screw for reversing attaching the head.
(6) Remove the head on the front side of the head mount.
Fig.1
Fig.2
Fig.3
Cassette mechanism assembly Fly wheelR
Trigger armHead mount
Head
Fly wheel R
Azimuth screw
for reversing
Flexible wire
Spring
CN31
Head amplifer & mecha control board
Head