JVC UXG-5 Service manual

SERVICE MANUAL

MICRO COMPONENT SYSTEM

MB43120058

UX-G5

Area suffix

A ------------------------ Australia
US ------------------------ Singapore
UP ----------------------------- Korea
UT ---------------------------- Taiwan
UW ----------- Brazil,Mexico,Peru
UY ------------------------ Argentina
UJ ---------------------- U.S.Military

CA-UXG5 SP-UXG5SP-UXG5

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18

COPYRIGHT © 2005 Victor Company of Japan, Limited

No.MB431

2005/8

SPECIFICATION

Amplifier section Output Power 100 W (50 W+50 W) at 6 Ω (10% THD)

Speakers Impedance 6 Ω - 16 Ω
Audio Input AUX 400 mV/50 kΩ

Tuner section FM tuning range 87.50 MHz - 108.00 MHz

AM tuning range 531 kHz - 1 710 kHz (at 9 kHz)

530 kHz - 1 710 kHz (at 10 kHz)

CD player section Dynamic range 85 dB

Signal-to-noise ratio 85 dB

Wow and flutter Immeasurable

Cassette deck section Frequency response: Normal (type l) 60 Hz - 14 000 Hz

Wow and flutter 0.15% (WRMS)

General Power requirement AC 110 V - 127 V / 220 V - 240 V (adjustable with the voltage selector),

50 Hz/60 Hz

Power consumption 90 W (at operation)

0.8 W (on standby)

Dimensions (approx.) 175 mm × 232 mm × 412 mm (W/H/D)

Mass (approx.) 6.6 kg

Speakers Type 2-way Bass reflex

Speaker units Woofer 10 cm cone × 1

Tweeter 4 cm cone × 1
Impedance 6 Ω
Dimensions (approx.) 144 mm × 231 mm × 201 mm (W/H/D)

Mass (approx.) 2.0 kg each

Design and specifications are subject to change without notice.

1-2 (No.MB431)

SECTION 1

PRECAUTION

1.1 Safety Precautions

(1) This design of this 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 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.).

AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)

0.15 F AC TYPE

Place this
probe on

1500 10W

Good earth ground

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 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 exposed
metal part.

(No.MB431)1-3

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

1-4 (No.MB431)

SECTION 3

DISASSEMBLY

3.1 Disassembly of Right plate left plate Top cover

Replacement of the fuses and AMP TR .THMS RES. Transistor. 7808 IC.

3.1.1 Replacing the fuses
(See Fig.1)

• Prior to performing the following procedure, remover right

plate, left plate, top cover.
(1) Replace the fuses inside.

Caution:

Be sure to use fuses with the specified

3.1.2 Replacing the AMP TR
(See Fig.2)

• Prior to performing the following procedure, remove the right

plate, left plate, top cover.
(1) Remove the four screws A from the heat sink between

AMP TR four.

(2) Remove the solder fixing the AMP TR.

FUSE

Fig.1

B

3.1.3 Replacing the THMS RES
(See Fig.2)

• Prior to performing the following procedure, remove right plate,

left plate, top cover.
(1) Remove the one screw B from heat sink.
(2) Remove the solder fixing THMS RES.

3.1.4 Replacing the 7808 IC
(See Fig.3)

(1) Remove the two screws D from heat sink.
(2) Remove the solder fixing transistor.

THMS RES

Fig.2

D

A

(TR)

Fig.3

(No.MB431)1-5

3.1.5 Removing the transformer cover

r

(See Fig.4)

(1) Remove the ten screws E from top cover.
(2) Take off transformer cover from rear plate.

E

3.1.6 Removing the Right plate
(See Fig.5)

(1) Remove the two screws F.
(2) Take off right plate from main body.

E

SPEAKERS IMPEDANCE:6 16

E

Transforme
cover

E

Fig.4

Right plate

F

3.1.7 Removing the Left plate
(See Fig.6)

(1) Remove the two screws G.
(2) Take off left plate from main body.

1-6 (No.MB431)

Fig.5

Left plate

G

Fig.6

3.1.8 Removing the TOP COVER

(See Fig.7 to 9)

(1) Remove the two screws H1 (See Fig.7, 8).
(2) Disengage the claws H2 on both side of the front cabinet

(See Fig.7, 8).

(3) Rotate top cover and let's away from main body (See

Fig.9).

Caution:

When you rotate top cover, must to slow raise, Don't to destroy
the two claws of front cabinet.

H1

H2

Top cover

Fig.7

H2

H1

Fig.8

Fig.9

(No.MB431)1-7

3.1.9 Removing the main board
(See Fig.10 to 13)

(1) Remove the two screws J1. (See Fig.10)
(2) Disconnect the FFC cable J2 from the connector CN661 on

main board. (See Fig.10)

(3) Disconnect the FFC cable J3 from the connector CN402

main board. (See Fig.11)

(4) Disconnect the FFC cable J4 from the connector CN681

main board. (See Fig.12)

(5) Remove main board from AMP board after disconnect the

connector J319

and CN601. (See Fig.13)

on

on

J1 J1

J2

Fig.10

J3

J5

Fig.11

J4

Fig.12

1-8 (No.MB431)

Fig.13

3.1.10 Removing the Power board

(See Fig.14 to 16)

(1) Remove the two screws K1 from CD MECH cover and

power board. (See Fig.14)

(2) Remove the two screws K1 from rear plate and power

board. (See Fig.14-1)

(3) Disconnect the wire K2 from the connector CN102

AMP board. (See Fig.15)

(4) Disconnect the two wire K3 from the connector CN901

. (See Fig.16)

CN902

on the

Power board

and

K1

Fig.14

k1

K3

Fig.14-1

K2

Fig.15

Fig.16

(No.MB431)1-9

3.1.11 Removing the Rear plate assembly
(See Fig.17 to 18)

(1) Disengage the claws I1 on both sides of bottom plate. (See

Fig.17)

(2) Disconnect the wire I2 from the connector CN105 on the

AMP board. (See Fig.18)

Rear plate assembly

I1

Fig.17

3.1.12 Removing the fan
(See Fig.19)

(1) Removing the four screws M2.

3.1.13 Removing the Tuner pack
(See Fig.19)

(1) Removing the two screws M1.

I2

M1

Tuner pack

M1

Fig.18

M2

M2

1-10 (No.MB431)

M2 Fan

Fig.19

M2

3.1.14 Removing the cassette machine from top cover

(See Fig.20 to 22)

(1) Disconnect the wire E1 from connector of the cassette ma-

chine. (See Fig.20)

(2) Disconnect the wire E2 from connector of the cassette ma-

chine. (See Fig.21)
(3) Remove the four screws E3 from top cover. (See Fig.22)
(4) Take out cassette machine.

TOP COVER

E1

Fig.20

E2

TOP COVER

CASSETTE
MECHA

TOP COVER

CASSETTE
MECHA

Fig.21

E3E3

Fig.22

E3E3

(No.MB431)1-11

3.1.15 Removing the key board

A

(See Fig.23)

(1) Remove the eight screws P from the front cabinet and the

key board.

Key board

3.1.16 Removing the AUX board
(See Fig.24)

(1) Remove the two screws Q from the front cabinet and the

aux board.

3.1.17 Removing the phones board
(See Fig.24)

(1) Remove the two screws R from the front cabinet and the

phones board.

P

ux board

P

Fig.23

Q

Fig.24

P

Phones board

R

1-12 (No.MB431)

3.1.18 Removing the CD MECH COVER

(See Fig.25, 26)

(1) Remove the four screws S.

CD Mech Cover

S

Fig.25

S

Fig.26

(No.MB431)1-13

3.1.19 Removing the CD MECH Assembly
(See Fig.27, 28)

(1) Remove the two screws T from the CD MECH-F and CD

MECHANISM assembly. (See Fig.27)

(2) Remove the two screws T from the CD MECH-B and CD

MECHANISM assembly. (See Fig.28)

(3) Take out CD MECHANISM assembly from the CD MECH-

F between the CD MECH-B.

CD MECH Assembly

T

Fig.27

T T

Fig.28

1-14 (No.MB431)

SECTION 4

ADJUSTMENT

4.1 Measuring instructions required for adjustment

• AM signal generator

• FM signal generator

• Inter medicate frequency sweep generator

• FM stereo signal generator

• Low-frequensy oscillator (osillation frequency 50 Hz - 20 kHz, 0 dB output with 600 Ω impedance)

• Attenuator (600 Ω impedance)

• Electoronic voltmeter

• Distortion meter

• Torque gauge (cassette for CTG-N)

• Wow & flutter meter

• Frequency counter meter

4.2 Test tape

• Playback tape

VT712 (tape speed, wow flutter)
VT724 (reference level)
VT703L (head azimuth)
VT738 (frequency responce)

• Recording tape

AC225 (type I)

• Power supply voltage

AC220V - 240V 50Hz

4.3 Measuring instruments

• Radio section

FM : 1 kHz, 22.5kHz deviation
FM stereo : 1 kHz, 67.5 kHz deviation, pilot signal 7.5 kHz
AM : 1 kHz, 30% modulation

Reference output : 0 dB (1 V) 4 Ω
Headphone output : -10 dB (0.1V) 32 Ω

4.4 Amplifier section

• Reference output : Speaker output 0 dB (1 V) / 4 Ω

Headphone output -10 dB (0.1 V) / 32 Ω

4.5 CD section

• Test disc : CTS-1000 (JVC)

TCD-731R (A-BEX)
TCD-712R (A-BEX)
TCD-785 (A-BEX)

(No.MB431)1-15