JVC UX-G5 User manual

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.MB431
2005/8
MICRO COMPONENT SYSTEM
MB43120058
UX-G5
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
CA-UXG5 SP-UXG5SP-UXG5
Area suffix
A ------------------------ Australia
US ------------------------ Singapore
UP ----------------------------- Korea
UT ---------------------------- Taiwan
UW ----------- Brazil,Mexico,Peru
UY ------------------------ Argentina
UJ ---------------------- U.S.Military

1-2 (No.MB431)
SPECIFICATION
Design and specifications are subject to change without notice.
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

(No.MB431)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.MB431)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MB431)1-5
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
Fig.1
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 Afrom the heat sink between
AMP TR four.
(2) Remove the solder fixing the AMP TR.
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 Bfrom heat sink.
(2) Remove the solder fixing THMS RES.
Fig.2
3.1.4 Replacing the 7808 IC
(See Fig.3)
(1) Remove the two screws Dfrom heat sink.
(2) Remove the solder fixing transistor.
Fig.3
FUSE
A
B
(TR)
THMS RES
D

1-6 (No.MB431)
3.1.5 Removing the transformer cover
(See Fig.4)
(1) Remove the ten screws Efrom top cover.
(2) Take off transformer cover from rear plate.
Fig.4
3.1.6 Removing the Right plate
(See Fig.5)
(1) Remove the two screws F.
(2) Take off right plate from main body.
Fig.5
3.1.7 Removing the Left plate
(See Fig.6)
(1) Remove the two screws G.
(2) Take off left plate from main body.
Fig.6
SPEAKERS IMPEDANCE:6 16
E
E
Transforme
r
cover
E
E
F
Right plate
G
Left plate

(No.MB431)1-7
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.
Fig.7
Fig.8
Fig.9
H1 Top cover
H2
H1
H2

1-8 (No.MB431)
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 on
main board. (See Fig.11)
(4) Disconnect the FFC cable J4 from the connector CN681 on
main board. (See Fig.12)
(5) Remove main board from AMP board after disconnect the
connector J319 and CN601. (See Fig.13)
Fig.10
Fig.11
Fig.12
Fig.13
J1 J1
J2
J3
J4
J5

(No.MB431)1-9
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 on the
AMP board. (See Fig.15)
(4) Disconnect the two wire K3 from the connector CN901 and
CN902. (See Fig.16)
Fig.14
Fig.14-1
Fig.15
Fig.16
Power board
K1
k1
K2
K3

1-10 (No.MB431)
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)
Fig.17
Fig.18
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.
Fig.19
I1
Rear plate assembly
I2
M1
M2
M2 Fan M2
M2
M1
Tuner pack

(No.MB431)1-11
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.
Fig.20
Fig.21
Fig.22
TOP COVER
E1
E2
TOP COVER
CASSETTE
MECHA
E3E3
E3E3
TOP COVER
CASSETTE
MECHA

1-12 (No.MB431)
3.1.15 Removing the key board
(See Fig.23)
(1) Remove the eight screws Pfrom the front cabinet and the
key board.
Fig.23
3.1.16 Removing the AUX board
(See Fig.24)
(1) Remove the two screws Qfrom the front cabinet and the
aux board.
3.1.17 Removing the phones board
(See Fig.24)
(1) Remove the two screws Rfrom the front cabinet and the
phones board.
Fig.24
Key board
P
P
P
A
ux board
Phones board
QR

(No.MB431)1-13
3.1.18 Removing the CD MECH COVER
(See Fig.25, 26)
(1) Remove the four screws S.
Fig.25
Fig.26
CD Mech Cover
S
S

1-14 (No.MB431)
3.1.19 Removing the CD MECH Assembly
(See Fig.27, 28)
(1) Remove the two screws Tfrom the CD MECH-Fand CD
MECHANISM assembly. (See Fig.27)
(2) Remove the two screws Tfrom the CD MECH-Band CD
MECHANISM assembly. (See Fig.28)
(3) Take out CD MECHANISM assembly from the CD MECH-
Fbetween the CD MECH-B.
Fig.27
Fig.28
CD MECH Assembly
T
T T

(No.MB431)1-15
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 Ωimpedance)
• Attenuator (600 Ωimpedance)
• 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)

1-16 (No.MB431)
4.6 Cassette amplifier section
4.7 Tuner section
Item Measuring condition Check and adjustment procedure Standard value Adjusting part
Head azimuth
adjustment
Tape speed
and
wow/flutter
check and
adjustment
PB frequency
responce
check
Bias frequency
check
REC and PB
frequency
responce
adjustment
Head azimuth
adjusting screw
(to be used only
after head re-
placement)
Tape speed :
motor semifixed
resistor
check only
L203
Output level :
within +/-2dB
of maximum
output level
2940 to 3090 Hz
within 0.38%
(unweighted)
deviation between
1 kHz and 8 kHz :
0 (+3 to -6) dB.
Level difference
between REC and
PB : within 0
(+3 to 6) dB
Phase defference
L and R channels:
minimum
1.Plyback the test tape VT703.
2.Adjust the head azimuth adjusting screw
so that the phase difference between the
R and L channels is minimized at an
output level that is within +/- 2dB of the
maximum output level.
After this adjustment, lock the head
azimuth adjusting screw with screw
sealant to cover more than a half of the
screw head.
3.When the head azimuth is maladjusted,
correct it with the head azimuth adjusting
screw.
1.Plyback the test tape VT712 by the end
of position.
2.Connect a frequency counter and check
that it reads between 2940 and 3090 Hz.
If not, adjust the frequenct with the motor
semifixed resistor.
3.Check that the wow / flutter is 0.38%
(unweighted).
Playback the test tape VT738 while confir-
ming that deviation between the 1 kHz
signal and 8 kHz signal should be
0 (+3 to -6) dB.
Set the TUNER or CD function and with
TAPE to record. Check to see if the
frequency at the measuring point (R335 or
R336) is 60 kHz +/-1 kHz if not adjust T360
until the frequency counter indicates
60 kHz +/- 1 kHz.
At TUNER, set the BAND to the FM
position, and record the reference 1 kHz
signal and 8 kHz signal altemately
repeatedly. While playing back the
recorded signal differ from that of the 1 kHz
signal by within 0 (+3 to 6) dB.
Test tape : VT703
Signal output terminal :
PHONES
(with 32 ohm load)
Test tape : VT712
Signal output terminal :
PHONES
(with 32 ohm load)
Test tape : VT738
Signal output terminal :
PHONES
(with 32 ohm load)
Test tape : normal
Signal output terminal :
Casssette R/P head
Test tape : AC225
Signal input : FM 22.5
dev, 60dBu with
emphasis
Signal output terminal :
PHONES
(with 32 ohm load)
Item Measuring condition Check and adjustment procedure Standard value Adjusting part
AM IF
adjustment
AM tracking
adjustment
Tuner 114 kHz
filter the waves
adjustment
T203
T201
T204
R245
TC201
1.Set the intermediate frequency sweep
generator to AM 450 kHz.
2.Adjust the T203 from maximum and
center output.
1.Set the TUNER at 522 kHz adjust T201
until the test pin of R245 voltage at
1.55 V +/- 0.1 V.
2.Set the TUNER at 1629 kHz, check the
pin of R245 voltage at 8.4 V +/- 6V.
3.Set the TUNER ang S/G at 612 kHz,
adjust T202 for maximum output.
4.Set the TUNER and S/G at 1404 kHz,
adjust T201 for maximum output.
5.Repwat the above step 3 and 4.
1.Set the unit in standby mode. Input 114
kHz signal to IC101 pin 19.
2.Adjust the T204 for output voltage
minimum.
Signal input : Loop
antenna
Signal output : IC201
pin 18
Signal input : Loop
antenna
Signal output : PHONES
(with 32 ohm load)
Signal input : IC101
pin 19
Signal output : IC101
pin 18

(No.MB431)1-17
4.8 Location of adjusting parts
Cassette mechanism section
CASSETTE
MOTOR
Tape speed adj.
+-
Main board assembly
(BIAS FREQUENCY)
T201
(AM OSC)
T360
(AM RF)
(AM RF)
(AM IF)
(AM VT)
R245
TC201
T203
T204
(114 kHz)
T202

1-18 (No.MB431)
SECTION 5
TROUBLESHOOTING
This service manual does not describe TROUBLESHOOTING.

(No.MB431)1-19

(No.MB431)
AV & MULTIMEDIA COMPANY AUDIO/VIDEO SYSTEMS CATEGORY 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan
Victor Company of Japan, Limited
VPT
Printed in Japan