JVC UX-G70A User manual

SERVICE MANUAL
COPYRIGHT © 2006 Victor Company of Japan, Limited No.MB551
2006/7
MICRO COMPONENT SYSTEM
MB55120067
UX-G70A,UX-G70UJ,UX-G70UN
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-35
CA-UXG70 SP-UXG70SP-UXG70

1-2 (No.MB551)
SPECIFICATION
Design and specifications are subject to change without notice.
Amplifier section
(CA-UXG70)
Output Power for A and UN versions 160 W (80 W+80 W) at 6 Ω(10% THD)
For UJ version 120 W per channel, min. RMS, driven into 6 Ωat 1kHz with no more than
10% total harmonic distortion.
Audio Input LINE IN 500 mV/49 kΩ(at "L.IN LVL1")
250 mV/49 kΩ(at "L.IN LVL2")
125 mV/49 kΩ(at "L.IN LVL3")
GAME IN 500 mV/49 kΩ(for UJ version)
MIC 1.6 mV/10 kΩ(for UN version)
Audio OutputLINE OUT 1.0 Vrms (3 kΩ) (at "L.OUT LVL1")
500 mVrms (1.5 kΩ) (at "L.OUT LVL2")
SUBWOOFER OUT 260 mVrms/3.9 kΩ
HEADPHONES OUT 17 mW/32 Ω
Digital output DVD OPTICAL DIGITAL OUT -21 dBm to -15 dBm (660 nm ±30 nm)
USB input USB AUDIO
Video output Color system NTSC or PAL(interlaced/progressive)
VIDEO (composite) 1 V(p-p)/75 Ω
S-VIDEO Y (luminance) : 1 V(p-p)/75 Ω
C (chrominance, burst) : NTSC : 0.286 V(p-p)/75 Ω
C (chrominance, burst) : PAL : 0.3 V(p-p)/75 Ω
COMPONENT (Y) : 1 V(p-p)/75 Ω
(PB/PR) : 0.7 V(p-p)/75 Ω
Speaker impedance 6 Ω- 16 Ω
Headphone impedance 16 Ω- 1 k Ω
Tuner section FM tuning range 87.5 MHz - 108.0 MHz
AM (MW) tuning range 531 kHz - 1 710 kHz (at 9 kHz intervals)
530 kHz - 1 710 kHz (at 10 kHz intervals)
Tape section Frequency response 60 Hz - 14 000 Hz
Wow and flutter 0.15 % (WRMS)
Disc player section Playable disc DVD Video/DVD Audio/CD/VCD/SVCD
CD-R/CD-RW (CD/SVCD/VCD/MP3/WMA/JPEG/MPEG-1/MPEG-2/ASF/
DivX format)
DVD-R/-RW (DVD-VR/DVD Video/MP3/WMA/JPEG/MPEG-1/MPEG-2/
ASF/DivX format)
+R/+RW(DVD Video format)
DVD-ROM (DVD Video format)
Dynamic range 80 dB
Horizontal resolution 500 lines
Wow and flutter Immeasurable
General Power requirement AC 240 V , 50 Hz for Australia
AC 110 V/AC 127 V/AC 220 V/ AC 230 V-240 V (adjustable with the voltage
selector), 50 Hz/60 Hz
Power consumption For A and UN versions 95 W (at operation)
18 W (at standby)
3.9 W (at standby display OFF mode)
For UJ version 90 W (at operation)
14 W (at standby)
1.0 W (at standby display OFF mode)
Dimensions (approx.) 175 mm ×250 mm ×411 mm (W/H/D)
Mass (approx.) 7.9 kg
Speakers
(SP-UXG70)
Speaker units Tweeter 1.5 cm dome ×1
Squawker 4 cm cone ×1
Woofer 13.5 cm cone ×1
Impedance 6 Ω
Dimensions (approx.) 166 mm ×250 mm ×232 mm (W/H/D)
Mass (approx.) 2.8 kg each

(No.MB551)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.MB551)
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 laser products.
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 pickup unit.
• Apply solder to the short land sections before the card wire is disconnected from the connecto on the servo board. (If the card wire
is disconnected without applying solder, the pickup may be destroyed by static electricity.)
• In the assembly, be sure to remove solder from the short land sections after connecting the card wire.
1M
Conductive material
(conductive sheet) or iron palate
(caption)
Anti-static wrist strap
Card wire
DVD pickup
DVD changer mechanism assembly
Connector
Short land section

(No.MB551)1-5
1.8 Important for laser products
1.CLASS 1 LASER PRODUCT
2.CAUTION :
(For U.S.A.) Visible and/or invisible class II laser radiation
when open. Do not stare into beam.
(Others) Visible and/or invisible class 1M laser radiation
when open. Do not view directly with optical instruments.
3.CAUTION : Visible and/or invisible laser radiation when
open and inter lock failed or defeated. Avoid direct
exposure to beam.
4.CAUTION : This laser product uses visible and/or 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 defeated. 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 here in may result in
hazardous radiation exposure.
REPRODUCTION AND POSITION OF LABELS and PRINT
!Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.
WARNING LABEL and PRINT

1-6 (No.MB551)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

(No.MB551)1-7
SECTION 3
DISASSEMBLY
3.1 Main Body
3.1.1 Removing the side panel
(See Fig.1, 2)
(1) Remove the six screws Aattaching the side panel. (See
Fig.1)
(2) Remove the four screws Battaching the side panel. (See
Fig.2)
3.1.2 Removing the top cover
(See Fig.1, 3, 4)
(1) Remove the one screw Cattaching the top cover. (See
Fig.1)
(2) Remove the two screws Dattaching the top cover. (See
Fig.3)
(3) Disconnect the card wires from the connectors CN710,
CN707 of the main board. (See Fig.4)
Fig.1
Fig.2
Fig.3
Fig.4
A
A
CG
B
B
D
CN707CN710

1-8 (No.MB551)
3.1.3 Removing the front panel
(See Fig.5 to 7)
(1) Disconnect the card wire from the connector CN359 of the
power amplifier board. (See Fig.5)
(2) Disconnect the card wire from the connector CN706 of the
main board. (See Fig.5)
(3) Disconnect the connector wire from the connector CN713
of the main board. (See Fig.5)
(4) Remove the two screws Eand two screws Fattaching the
front panel. (See Fig.6)
(5) Disengage the hook a. (See Fig.6)
(6) Disengage the two hooks band then remove the front pan-
el. (See Fig.7)
Fig.5
Fig.6
Fig.7
3.1.4 Removing the rear cover
(See Fig.1)
(1) Remove the two screws Gattaching the rear cover.
CN713 CN359 CN706
E
F
a
b

(No.MB551)1-9
3.1.5 Removing the video board
(See Fig.8, 9)
(1) Disconnect the card wires from the connectors CN401,
CN402 of the video board. (See Fig.8)
(2) Remove the three screws Hattaching the video board.
(See Fig.9)
3.1.6 Removing the tuner
(See Fig.9, 10)
(1) Disconnect the card wire from the connector CN712 on the
main board. (See Fig.10)
(2) Remove the two screws Jattaching the tuner. (See Fig.9)
3.1.7 Removing the fan
(See Fig.9, 10)
(1) Disconnect the connector wire from the connector CN708
of the main board. (See Fig.10)
(2) Remove the two screws Kattaching the fan. (See Fig.9) Fig.8
Fig.9
Fig.10
CN401
CN402
J
K
H
CN712
CN708

1-10 (No.MB551)
3.1.8 Removing the rear panel
(See Fig.11, 12)
(1) Remove the ten screws Lattaching the rear panel. (See
Fig.11)
(2) Disengage the two hooks cand then remove the rear pan-
el. (See Fig.12)
Fig.11
Fig.12
L
L
L
L
c

(No.MB551)1-11
3.1.9 Removing the power supply board
(See Fig. 13)
(1) Disconnect the connector wires from the connectors
CN903, CN904 and CN905, CN906 of the power supply
board.
(2) Remove the one screw Mattaching the power supply
board.
(3) Disconnect the connector CN901 connecting the power
amplifier board and then removing the power supply board.
Fig.13
3.1.10 Removing the main board
(See Fig. 14)
(1) Disconnect the card wire from the connector CN703,
CN704 of the main board.
(2) Remove the one screw Nattaching the main board.
(3) Disconnect the connectors CN701 and CN702 of the main
board connecting the power amplifier board.
Fig.14
3.1.11 Removing the amplifier board
(See Fig. 15)
(1) Disconnect the amplifier board from the connector CN353
and CN354 of the power amplifier board.
Fig.15
M
CN901
CN903
CN904
CN905
CN906
CN703 CN702
CN701
N
CN704
CN353CN354

1-12 (No.MB551)
3.1.12 Removing the power amplifier board
(See Fig. 16)
(1) Disconnect the connector wire from the connector CN361
of the power amplifier board.
(2) Remove the four screws Pattaching the power amplifier
board.
(3) Disconnect the card wire from the connector CN356 of the
power amplifier board.
Fig.16
3.1.13 Removing the power transformer
(See Fig. 17)
(1) Remove the four screws Qattaching the power transform-
er.
Fig.17
P
P
CN356
CN361
Q
Q

(No.MB551)1-13
3.1.14 Removing the DVD changer mechanism assembly
(See Fig. 18, 19)
(1) Remove the four screws Rattaching the DVD mechanism
assembly. (See Fig.18)
(2) Remove the two screws Sand two screws Tattaching the
DVD changer mechanism assembly. (See Fig.19)
Fig.18
Fig.19
R
R
T
S

1-14 (No.MB551)
3.1.15 Removing the jack board
(See Fig. 20)
(1) Remove the three screws Uattaching the jack board.
3.1.16 Removing the FL board
(See Fig. 20)
(1) Remove the four screws Vattaching the FL board.
(2) Disconnect the card wire from the connector CN100 of the
FL board.
Fig.20
3.1.17 Removing the switch board
(See Fig. 21)
(1) Remove the volume knob.
(2) Remove the twelve screws Wattaching the switch board.
Fig.21
U
V
V
V
CN100
W
W
W
W

(No.MB551)1-15
3.1.18 Removing the cassette mechanism assembly
(See Fig. 22)
(1) Remove the four screws Xattaching the cassette mecha-
nism assembly.
(2) Remove the one screws Yattaching the earth wire.
3.1.19 Removing the MIC board
(See Fig. 22)
(1) Remove the MIC volume knob.
(2) Remove the two screws Zattaching the MIC board.
Fig.22
Y
X
X
X Z

1-16 (No.MB551)
3.2 DVD changer mechanism assembly section
Remove the DVD changer mechanism assembly from the main body. (See "Removing the DVD changer mechanism assembly".)
3.2.1 Removing the tray assemblies
(See Figs.1 to 5)
(1) From the top side of the main body, remove the two screws
Afrom the top cover and release the two joints aon the
both sides of the DVD changer mechanism assembly. (See
Figs.1 and 2.)
(2) Remove the two rods from the top cover and remove the
top cover from the lifter assembly. (See Figs.1 and 2.)
(3) Remove the open det. lever on the left side of the DVD
changer mechanism assembly. (See Fig.3.)
(4) From the right side of the DVD changer mechanism as-
sembly, draw out the tray assemblies toward the front while
pushing the part bof the side (R) assembly. (See Figs.4
and 5.)
Note:
The tray can be locked if all tray assemblies are at-
tached.
(5) From the topside of the DVD changer mechanism assem-
bly, move the stopper tabs cin the direction of the arrow
and release them. Pull out the tray assemblies from the
DVD changer mechanism assembly. (See Fig. 5.)
Note:
Remove the tray assembly from top tray 5 in order.
Reference:
When reattaching the tray assembly, or when removing the
disc remaining inside, refer to another section "3.3.15 Taking
out the disc in the play mode". Fig.1
Fig.2
Top cover
Lifter assembly
Rods
A
a
a
A
a
Rods Top cover
Lifter assembly
a

(No.MB551)1-17
Fig.3
Fig.4
Fig.5
Open det. leve
r
b
Tray assemblies Side(R) assembly
c
Tray assembly

1-18 (No.MB551)
3.2.2 Removing the DVD servo board
(See Figs.6 to 8)
Caution:
Solder the short land sections don the DVD pickup before dis-
connecting the card wire extending from the DVD pickup. If
you do not follow this instruction, the DVD pickup may be dam-
aged.
(1) From the topside of the DVD changer mechanism assem-
bly, solder the short land sections don the DVD pick up.
(See Fig.6.)
(2) From the bottom side of the DVD changer mechanism as-
sembly, disconnect the card wire from the connectors
(CN201, CN451) on the DVD servo board. (See Fig.7.)
Reference:
When connecting the card wire to the connector CN451,
pass it through the sections eon the DVD traverse
mechanism assembly. (See Fig.7.)
(3) Disconnect the wires from the connectors (CN452, CN453)
on the DVD servo board. (See Fig.7.)
(4) Remove the two screws Battaching the DVD servo board.
(See Fig.7.)
(5) From the reverse side of the DVD servo board, release the
lock of the connector CN101 in the direction of the arrow
and disconnect the card wire. (See Fig.8.)
Caution:
Unsolder the solders from the short land sections dafter reas-
sembling. (See Fig.6.)
3.2.3 Removing the switch board
(See Fig.7)
(1) From the bottom side of the DVD changer mechanism as-
sembly, remove the screw Cattaching the switch board on
the DVD changer mechanism assembly.
(2) Disconnect the wires from the connectors (CN452, CN453)
on the DVD servo board.
(3) Release the wires from the section fand remove the switch
board.
(4) Release the wires from the sections gand remove the
switch board.
Reference:
When reassembling, pass the wires through the sections (f, g)
as before.
Fig.6
Fig.7
Fig.8
DVD pickup
DVD changer mechanism assembly
d
C
DVD changer mechanism assembly
B
B
CN201
eCN453
CN451
Switch board
DVD traverse mechanism assembly
DVD servo board
f
g
CN452
DVD servo board CN101
Lock

(No.MB551)1-19
3.2.4 Removing the motor board
(See Figs.9 and 10)
(1) From the top side of the DVD changer mechanism assem-
bly, remove the two belts from the motor pulleys. (See
Fig.9.)
Note:
Take care not to attach grease on the belt.
(2) Remove the two screws Dattaching the motors to the load-
er assembly. (See Fig.9.)
(3) From the bottom side of the DVD changer mechanism as-
sembly, remove the two screws E. (See Fig.10.)
(4) Disconnect the connector CN2 on the motor board from the
tray switch board and remove the motor board. (See
Fig.10.)
(5) Disconnect the card wire from the connector CN1 on the
forward side of the motor board. (See Fig.10.)
Note:
When connecting the card wire, let the card wire through the
slots hof the motor board. (See Fig.10.)
Reference:
You need not to remove the tray assemblies, and in such case,
move it.
3.2.5 Removing the motor
(See Fig. 10)
• Remove the motor board.
(1) From the reverse side of the motor board, unsolder the four
soldered sections ion the motor board.
(2) From the forward side of the motor board, remove the mo-
tors.
Fig.9
Fig.10
Motor Motor
Motor pulleys Loader assembly
Belt
Belt
D
D
E
h
CN2
Motors
i
CN1
E
Motor board
DVD changer mechanism assembly
Tray switch
board
Motors
Motor board

1-20 (No.MB551)
3.2.6 Removing the DVD traverse mechanism assembly
(See Fig.11)
• Remove the tray assemblies and DVD servo board.
(1) From the bottom side of the DVD changer mechanism as-
sembly, remove the three screws Fattaching the DVD
traverse mechanism assembly.
(2) Remove the wires from the section j.
(3) Take out the DVD traverse mechanism assembly from the
DVD changer mechanism assembly.
Fig.11
F
F
j
F
DVD changer mechanism assembly
DVD traverse mechanism assembly