JVC UXJ-55-V Service manual

MB057200312

S

S

SERVICE MANUAL

MICRO COMPONENT SYSTEM

UX-J55V

COMPACT

DIGITAL VIDEO

STANDBY/ON

1

3

2

4 65

DISPLAY

CLOCK

7 98

/TIMER

10

+10

SLEEP

TREBLEUPBASS

NEXT

PREV.

CANCELSET

DOWN

CD

FM/AM AUX

/SELECT

TAPE

FM

REV.

MODE

CD

MODE

REPEAT

RANDOM

RETURN

PRGM

AHB

STILL

PRO

KARAOKE

MPX

DIGITAL

ECHO

RM-

P-UXJ55V

COMPACT

COMPACT

P-UXJ55VCA-UXJ55V

Area Suffix

DIGITAL VIDEO

DIGITAL AUDIO

US ------------- Singapore
UN ------------------ Asean

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

COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED

No.MB057

2003/12

SPECIFICATION

Amplifier Output Power 120 W (60 W + 60 W) at 6 Ω (10% THD)

Audio input sensitivity
/Impedance (at 1 kHz)

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

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

General Power requirement AC 110 V/ 127 V/ 220 V/ 230 V - 240 V , adjustable with the voltage selector, 50 Hz/60 Hz

Design and specifications are subject to change without notice.

Speaker units Woofer 12.0 cm cone × 1

Impedance 6 Ω
Dimensions (approx.) 160 mm × 285 mm × 181.5 mm (W/H/D)
Mass (approx.) 2.4 kg each

Power consumption 130 W (at operation)

Dimensions (approx.) 490 mm × 286 mm × 323.3 mm (W/H/D)
Mass (approx.) 10.3 kg

AUX 400 mV/48 kΩ

AM 9 kHz intervals 531 kHz - 1 710 kHz

Midrange 4.0 cm cone × 1
Tweeter 2.0 cm dome × 1

3.4 W (on standby)

1-2 (No.MB057)

1.1 Safety Precautions

Good earth ground

d

AC VOLTMETER

SECTION 1

PRECAUTION

(1) This design of th is 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 ( ) 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 reassem­bling.

(5) Leakage shock hazard testing

After reassembling 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.

• 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, 1,000Ω per volt or more sensitivity
in the following manner. Connect a 1,500Ω 10W resistor
paralleled by a 0.15µF AC-type capacitor between an ex­posed 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.).

(Having 1000
ohms/volts,
or more sensitivity)

0.15 F AC TYPE

Place this
probe on

1500 10W

1.2 Warning

(1) This equipment has been designed and manufactured to

meet international safety standards.

(2) It is the legal resp onsibility 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 compone nts 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 pre­forming 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)

each expose
metal part.

(No.MB057)1-3

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 dio de) 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 sh eet) 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.

(caption)
Anti-static wrist strap

1M

Conductive material
(conductive sheet) or iron palate

(3) Handling the optical pickup

• In order to maintain quality during transport and before installation, both sides o f the laser diode on the replacem ent 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.

1-4 (No.MB057)

Flexible wire

Shorting round

Shorting round

CN601 on
mechanism
board

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.

!

Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.

REPRODUCTION AND POSITION OF LABEL and PRINT

WARNING LABEL and PRINT

Caution label

(No.MB057)1-5

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

1-6 (No.MB057)

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 A on the back of the main body.
(3) Remove the two screws B on each side an d remove the

metal cover in the direction of the arrow.

Volume knob

Metal cover

A

A

A

B

Fig.2

Fig.1

Fig.3

B

(No.MB057)1-7

3.1.2 Removing the rear cover

r

(See Fig.4)

(1) Remove the two screws D attaching the rear cover.

D

Rear cove

Fig.4

1-8 (No.MB057)

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 E attaching the rear panel.

Release the two joints a on the rear side and the two joints
b on each side.

(2) Remove the two screws F attaching the fan bracket and

release the two joints d on the rear panel, and remove.

(3) Disconnect the wire from the connector CN908

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 G attaching the MIC volume board

on the inside of the rear panel.

(2) Disconnect the wire from connector CN906

board on the back of the body.

on the main

on the main

F

E

E

EE

a

Rear panel

E

F

d

d

Fan assembly

E

b

Fig.5

CN906

Main board

Mic volum board

CN908

Fig.6

G

b

Rear panel

(No.MB057)1-9

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 H on the rear side and the screw

J in the side.

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

and CN904 on the main board.

CN902

(2) Pull the joint e in the direction of the arrow and remove the

VCD mechanism assembly backward while releasing the
joint f .

J

H

Tuner board

CN1

Fig.7

,

VCD mechanism assembly

e

e

Main board

f

CN903

CN904

CN902

Fig.8

1-10 (No.MB057)

3.1.7 Removing the main board / the heat sink boar d / 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 K attaching 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
main board.

(3) Remove the band and disconnect the wire from the

connector CN951
then remove the main board / the heat sink board from the
body.

(4) Release the two joints g of the main board and disconnect

the connector CN944
from the connector CN912 and CN911 of the main board
respectively, and remove.

(5) Remove the two screws L and the two screws M attaching

the heat sink.
(6) Remove the screw N attaching the speaker board.
(7) Disconnect the vocal cancel board from conne ctor CN905

on the main board.

on the power transformer assembly, and

and CN945 of the heat sink board

and CN916,CN917 on the

,

CN930

CN907

CN931

Main board

CN932

CN901

CN900

Vocal cancel board

CN905

CN916

CN917

Band

Main board

Main board

CN911

g

CN912

Power transformer assembly

CN951

Fig.10

Vocal cancel board

CN905

H

Fig.9

CN945

CN944

Heat sink board

Speaker board

Fig.11

(No.MB057)1-11

3.1.8 Removing the power transformer assemb ly
(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 conn ector J1000 on

the power transformer assembly.

(2) Remove the four screws P .

PP

Power transformer assembly

J1000

Fig.12

1-12 (No.MB057)

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 Q on each side. Release the two

joints h on the both sides and lift the front panel assembly
to release the joint j.

(2) Disconnect the card wire from the connector CN900

, CN930, CN931 and CN932 on the main board.

CN901

Front panel assembly

,

h

Q

Fig.13

Main board

j

CN932CN931 CN930

h

CN900 CN901

Q

Fig.14

Front panel assembly

(No.MB057)1-13

3.1.10 Removing the phones board

R

(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

board.

on the main

Mian board

CN907

Phones board

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 R attaching the cassette

mechanism assembly.

Fig.15

R

Cassette mechanism assembly

Fig.16

1-14 (No.MB057)

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 T attaching the switch board.
(2) Move the switch board in the direction of the arrow to

disconnect the wire from the connector CN762
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 U attaching the LCD board

assembly.

and the

T

LCD board assembly

UU

T

Switch board

Fig.17

Switch board

CN762 CN761

Fig.18

(No.MB057)1-15

3.1.14 Removing the control panel assembly

y

(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 Y attaching the control panel

assembly.

(2) Release the three joints k and open the cassette door

while pressing the cassette door, and then remove the
control panel assembly in the direction of the arrow.

Y

Y

Fig.19

k

Cotrol panel assembl

Fig.20

1-16 (No.MB057)

3.1.15 Remiving the control board

A

(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.

Control panel assembly

Volume knob

Fig.21

Control panel assembly

Control board

'

A'

Fig.22

A'

(No.MB057)1-17

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

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

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

servo control board.

Caution:

When reassembling, unsolder the short-circuit point after
connecting the card wire to CN601

on the CD board.

on the

on the CD ser-

on the CD

VCD mechanism assembly

CN606

Board bracket

D'

D'

VCD board

CN801

m m

CD servo control board

Fig.24

VCD mechanism assembly

CN101

B' B'

B'

Fig.23

Board cover

Short round

CN601

Card wire

CD servo
control board

Fig.25

1-18 (No.MB057)

Pick up board

Fig.26

Card wire

Short round

(No.MB057)1-19

3.2 Cassette mechanism assembly

3.2.1 Removing the Play/Record & Clear head
(See Fig.1~3)

(1) While moving the tri gger arm on the rig ht 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 counterclockwis e as you turn the flywheel

R counterclockwise (See Fig.2 and 3).

(3) Disconnect the flexible wire fro m connector CN31

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.

on the

Cassette mechanism assembly

Fig.1

Head

Fly wheelR

Trigger armHead mount

Flexible wire

Fly wheel R

Fig.2

Azimuth screw

Head

for reversing

Spring

CN31

Head amplifer & mecha control board

Fig.3

1-20 (No.MB057)

3.2.2 Removing the head amplifier & mechanism control board
(See Fig.4)

(1) Turn over the cassette mechanism assembly and remove

the three screws A attaching the head amplifier & mecha­nism control board.

(2) Disconnect the flexible wire from connector CN31

head amplifier & mechanism control board.

(3) Disconnect connector CN32

anism control board from connector CN1
board.REFERENCE: If necessary, unsolder the 4-pin wire
soldered to the main motor.

3.2.3 Removing the main motor
(See Fig.4~7)

(1) Remove the two screws B .
(2) Half raise the motor and remove the capstan belt from the

motor pulley.

ATTENTION:

Be careful to keep the capstan belt from grease. When reas­sembling, refer to Fig.6 and 7 for attaching the capstan belt.

Head amplifier & mecha control board

of the head amplifier & mech-

on the reel pulse

on the

Main motor assembly

Capstan belt

Fig.5

Main motor assembly

CN31

Flexible wire

A

AA

Fig.4

CN32

4pin wire

B

Main motor assembly

Motor pulley

Capstan belt

Fig.6

Main motor assembly

Fly wheel

Capstan belt

Motor pulley

Fig.7

(No.MB057)1-21