JVC UX-GD7 User manual

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.MB422
2005/8
MICRO COMPONENT SYSYTEM
MB42220058
UX-GD7
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
CA-UXGD7 SP-UXGD7SP-UXGD7
Area suffix
B ------------------------------ U.K.
E ---------- Continental Europe
EN ----------- Northern Europe
EV ------------- Eastern Europe
EE -------- Russian Federation

1-2 (No.MB422)
SPECIFICATION
Design and specifications are subject to change without notice.
Amplifier section Output power 140 W (70 W + 70 W) at 6Ω(10% THD)
Analog input AUX Sensitivity/Impedance (at 1 kHz): 400 mV/47 kΩ
USB input USB Ver.1.1
Digital output OPTICAL DIGITAL OUT -21 dBm to -15 dBm (660 nm ±30 nm)
VIDEO OUT Color system PAL
Video (composite) 1 V(p-p)/75Ω
S-video Y (luminance): 1 V(p-p)/75Ω
C (chrominance, burst): 0.3 V(p-p)/75Ω
RGB 0.7 V(p-p)/75Ω
COMPONENT (Y): 1 V(p-p)/75Ω
(PB/PR): 0.7 V(p-p)/75Ω
Speaker terminals Impedance 6Ω- 16Ω
Tuner section FM tuning range 87.50 MHz - 108.00 MHz
AM tuning range 522 kHz - 1 629 kHz
Disc player section Playable disc DVD Video/DVD Audio
CD/VCD/SVCD
CD-R/CD-RW (recorded in Audio CD/
Video CD/Super Video CD/MP3/JPEG/DivX format)
DVD-R (recorded in video/MP3/JPEG/DivX format)
DVD-RW/DVD-RAM (recorded in video/DVD-VR/MP3/JPEG/DivX
format)
Horizontal resolution 500 lines
Wow and flutter Immeasurable
General Power requirement AC 230 V , 50 Hz
Power consumption 150 W (at operation)
1.3 W (on standby)
Dimensions (approx.) 189 mm ×224 mm ×406 mm(W/H/D)
Mass (approx.) 6.5 kg
Speakers Type 2-way Bass-reflex type, Magnetically shielded
Speaker systems Woofer 12 cm cone ×1
Tweeter 4 cm cone ×1
Power handling capacity 70 W
Impedance 6Ω
Frequency range 45 Hz - 20 000 Hz
Sound pressure level 84 dB/W·m
Dimensions (approx.) 165 mm ×286 mm ×237 mm(W/H/D)
Mass (approx.) 2.8 kg each

(No.MB422)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
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.).
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.MB422)
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.MB422)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

1-6 (No.MB422)
SECTION 3
DISASSEMBLY
3.1 Disassembly of the main blocks of the set
Replacement of the fuses and the power IC.
3.1.1 Replacing the fuses
(See Fig. C)
• Prior to performing the following procedure, remove the rear
cover.
(1) Replace the fuses inside.
Caution:
Be sure to use fuses with the specified ratings.
Fig.C
3.1.2 Replacing the power IC
(See Fig. D)
• Prior to performing the following procedure, remove the rear
cover.
(1) Remove the two screws Hfrom the heat sink between the
power IC.
(2) Remove the solder fixing the power IC.
Fig.D
FUSE
(Location:F901)
Value: T1.25AL 250V
H

(No.MB422)1-7
3.2 MAIN BODY
3.2.1 Removing the Metal Side Left and the Metal Side Right
(See Fig. 1-1, Fig. 1-2 and Fig. 1-3)
(1) Unscrew the 10 screws Afrom the Rear Panel, the Top
Cover and the Chassis Main.
(2) Remove the Metal Side Left and the Metal Side Right.
Fig.1-1
Fig.1-2
Fig.1-3
A
A
A

1-8 (No.MB422)
3.2.2 Removing the Top Cover
(See Fig. 2-1, Fig. 2-2 and Fig. 2-3)
(1) Unscrew the 2 Screws Band 2 Screws C.
(2) Removing the Top Cover.
Fig.2-1
Fig.2-2
Fig.2-3
B
B
C

(No.MB422)1-9
3.2.3 Removing the Cabinet Front
(See Fig. 3-1, Fig. 3-2, Fig. 3-3 and Fig. 3-4)
(1) Unscrew the 3 Screws Dfrom the Chassis Main.
(2) Pulling out the 3 cable connectors from the Main Board unit
and the AMP Board unit then removing the Cabinet Front.
Fig.3-1
Fig.3-2
Fig.3-3
Fig.3-4
D
D
D
Connector
Connector
Connecto
r

1-10 (No.MB422)
3.2.4 Removing the Cover Heat Sink and the Fan
(See Fig.4-1, Fig.4-2 and Fig.4-3)
(1) Unscrew the 5 Screws Efrom the Chassis Main and the
Rear Panel.
(2) Pulling out the cable connector from the AMP Board then
removing the Cover Heat Sink and the Fan.
(3) Unscrew the 4 Screws Mfrom the Fan.
(4) Removing the Fan.
Fig.4-1
Fig.4-2
Fig.4-3
EE
E
E
E
CONNECTOR
M

(No.MB422)1-11
3.2.5 Removing the Rear Panel the Tuner and the Speaker Board
(See Fig.5-1, Fig.5-2 and Fig.5-3)
(1) Unscrew the 15 screws Cfrom the Main Board unit, the
Tuner, the Heat Sink, the Chassis Main and the scart
Board unit.
(2) Pulling out the 2 cable connectors from the AMP Board unit
and the Power Board unit then removing the Panel Rear,
the Tuner and the Speaker Board.
Fig.5-1
Fig.5-2
Fig.5-3
C
C
CONNECTOR
CONNECTOR

1-12 (No.MB422)
3.3 CABINET FRONTCHASSIS MAIN ASSEMBLY
3.3.1 Removing the Knob Volume, the Display Board and the USB Board
(See Fig.6-1 and Fig.6-2)
• Prior to performing the following procedure before removing
the Display Board.
(1) Pulling out the Knob Volume from the Display Board.
(2) Unscrew the 15 screws Ffrom the Cabinet Front, then tak-
ing out the Display Board and the USB Board.
Fig.6-1
Fig.6-2
KNOB VOLUME
F

(No.MB422)1-13
3.3.2 Removing the Main Board and the Power Board
(See Fig.7-1, Fig.7-2, Fig.7-3 and Fig.7-4)
(1) Pulling out the 5 cable connectors from Main Board unit
and the Power Board unit.
(2) Unscrew the 4 screws Gfrom the Mechanism Holder.
(3) Separating the Main Board and the Power Board from the
AMP Board vertically.
Fig.7-1
Fig.7-2
Fig.7-3
Fig.7-4
CONNECTOR
CONNECTOR
G
G

1-14 (No.MB422)
3.3.3 Removing the AMP Board and the Main Heat Sink
(See Fig.8-1 and Fig.8-2)
(1) Unscrew the 3 screws Gand 1 screw Cfrom the Mecha-
nism Holder, then removing the AMP Board.
(2) Unscrew the 2 screws Hthen removing the Main Heat Sink.
Fig.8-1
Fig.8-2
G
C
HH

(No.MB422)1-15
3.3.4 Removing the Mechanism Holder
(See Fig.9-1 and Fig.9-2)
(1) Unscrew the 4 screws Ifrom the Mechanism Holder.
(2) Removing the Mechanism Holder.
Fig.9-1
Fig.9-2
II
II

1-16 (No.MB422)
3.3.5 Removing the DVD Mechanism
(See Fig.10-1, Fig.10-2 and Fig.10-3)
Caution:
The DVD Mechanism may be taken out only when the Rear
Panel, the Tuner, the Speaker
Board, the Main Board, the Power Board, the AMP Board, the
Mechanism Front Holder and the Mechanism Back Holder
have been taken away.
(1) Unscrew the 4 screws Jfrom the Chassis Main.
(2) Separating the DVD Mechanism, the Mechanism Front
Holder and the Mechanism Back Holder from the Chassis
Main vertically.
(3) Unscrew the 4 screws Kfrom the Mechanism, then remov-
ing the Mechanism Front Holder and the Mechanism Back
Holder.
Fig.10-1
Fig.10-2
Fig.10-3
3.3.6 Removing the Transformer
(See Fig.11)
(1) Unscrew the 4 screws Lfrom the Chassis Main.
(2) Taking out the Bushing then removing the Silicon Steel
Sheet and the Transformer.
Fig.11
JJ
K
JJ
K
CD MECH Assembly
KK
L
LL
L

(No.MB422)1-17
SECTION 4
ADJUSTMENT
4.1 Measurement instruments required for adjustment
(1) Low frequency oscillator.
This oscillator should have a capacity to output 0dB to
600Ωat an oscillation frequency of 50Hz-20kHz.
(2) Attenuator impedance : 600Ω
(3) Electronic voltmeter
(4) Frequency counter
(5) Wow flutter meter
(6) Test tape
VT712 : For Tape speed and wow flutter (3kHz)
VT703 : For Head angle (10kHz)
(7) Blank tape
TAPE l : AC-225 TAPE II : AC-514
(8) Torque gauge : For play and back tension forward:
TW2111A, Reverse: TW2121A Fast Forward and Rewind:
TW2231A
(9) Test disc: CTS-1000(12cm),GRG-1211(8cm)
(10) Jitter meter
4.2 Measurement conditions
4.3 Radio input signal
4.4 Frequency Range
4.5 Standard measurement positions of volume and
switch
4.6 Precautions for measurement
(1) Apply 30pF and 33kΩto the IF sweeper output side and
0.082 F and 100kΩin series to the sweeper input side.
(2) The IF sweeper output level should be made as low as pos-
sible within the adjustable range.
(3) Since the IF sweeper is a fixed device, there is no need to
adjust this sweeper.
(4) Since a ceramic oscillator is used, there is no need to per-
form any MPX adjustment.
(5) Since a fixed coil is used, there is no need to adjust the FM
tracking.
(6) The input and output earth systems are separated.
In case of simultaneously measuring the voltage in both of
the input and output systems with an electronic voltmeter
for two channels, therefore, the earth should be connected
particularly.
(7) In the case of BTL connection amplifier, the minus terminal
of speaker is not for earthing. Therefore, be sure not to con-
nect any other earth terminal to this terminal. This system
is of an OTL system.
SECTION 5
TROUBLESHOOTING
This service manual does not describe TROUBLESHOOTING.
Power supply voltage :AC 230V (50Hz)
Measurement output
terminal
:Speaker out
:TP101(Measuring for TUNER/DECK/CD)
:Dummy load 6Ω
AM modulation frequency :400Hz
Modulation factor :30%
FM modulation frequency :1kHz
Frequency displacement :22.5kHz
AM 522kHz to 1629kHz
FM 87.5MHz to 108MHz
Power :Standby (Light STANDBY Indicator)
Sound Turbo ll / BASS/ TREBLE OFF
AHB PRO :OFF
Main VOL. :0 Minimum
Travers mecha set position :Disc 1

(No.MB422)
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

3-1
PARTS LIST
* All printed circuit boards and its assemblies are not available as service parts.
- Contents -
Exploded view of general assembly and parts list (Block No.M1)
Electrical parts list (Block No.01~05)
Packing materials and accessories parts list (Block No.M3)
[ UX-GD7 ]
3- 2
3- 5
3-12
Area suffix
B ------------------------------- U.K.
E ----------- Continental Europe
EN ------------ Northern Europe
EV -------------- Eastern Europe
EE --------- Russian Federation
MB422