JVC CA-UXB70 User manual

SERVICE MANUAL
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED No.MB013
2003/11
MICRO COMPONENT SYSTEM
MB013200311 UX-B70
TABLE OF CONTENTS
1PRECAUTION. . . . . ... . .. . ... . .. . ... . .. . ... . .. . ... . .. . ... . .. . ... . .. . ... . .. . ... . .. . ... . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-35
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
B -------------------------- U.K.
E ------ Continental Europe
EN --------Northern Europe
Area Suffix

1-2 (No.MB013)
SPECIFICATION
Design and specifications are subject to change without notice.
Amplifier Section-CA-UXB70
Output Power (IEC 268-3) 120 W (60 W + 60 W) at 6 Ω(10% THD)
Analog input sensitivity/Impedance (at 1 kHz) AUX/DVD:400 mV/48 kΩ
Speakers/Impedance 6 Ω- 16 Ω
Tuner FM tuning range 87.50 MHz-108.00 MHz
AM (MW) tuning range 522 kHz-1 629 kHz
CD player CD Capacity 5 CDs
Dynamic range 87 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)
General Power requirement AC 230 V , 50 Hz
Power consumption 110 W (at operation)
17 W (on standby)
1.4 W (in power save mode)
Dimensions (W/H/D) (approx.) 175 mm ×239.5 mm ×378 mm
Mass (approx.) 8 kg
Speaker Section-SP-UXB70
Type 2-way bass-reflex type
Speakers Woofer 12 cm cone ×1
Tweeter 2 cm dome ×1
Power handling capacity 60 W
Impedance 6 Ω
Frequency range 55 Hz to 20 kHz
Sound pressure level 85 dB/W·m
Dimensions (W/H/D) (approx.) 145 mm ×239.5 mm ×202 mm
Mass (approx.) 2.5 kg each

(No.MB013)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)
0.15 F AC TYPE

1-4 (No.MB013)
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.MB013)1-5
1.6 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.
1.6.1 Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as 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 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.
1.7 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.
1.8 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 CN101 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.
1M
Conductive material
(conductive sheet) or iron palate
(caption)
Anti-static wrist strap
Pickup Flexible board
Short round Card wire
CN601
Servo control board
Card wire

1-6 (No.MB013)
1.9 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.
REPRODUCTION AND POSITION OF LABEL and PRINT
WARNING LABEL and PRINT
!Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.

(No.MB013)1-7
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.

1-8 (No.MB013)
SECTION 3
DISASSEMBLY
3.1 Main body
3.1.1 Removing the metal cover
(See Fig.1 ~ 3)
(1) Remove the six screws Aon the back of the body.
(2) Remove the two screws Bon the right and left sides of the
body.
(3) Detach the rear side of the metal cover upward while pull-
ing the bottom of each side, and remove the metal cover.
Fig.1
Fig.2
Fig.3
Metal cover
AA
A
B
B

(No.MB013)1-9
3.1.2 Removing the front panel assembly
(See Fig.4 ~ 8-2)
• Prior to performing the following procedure, remove the metal
cover.
(1) Disconnect the card wire from connector CN700 on the mi-
com board on the right side of the body.
(2) Disconnect the wire from connector CN104 on the regula-
tor board on the left side of the body and release the wire
from the clamp.
(3) Remove the two screws Con top of the body.
(4) Remove the two screws Don the bottom of the body.
(5) Release the joint aon the bottom and the joint bon each
side of the body using the screwdriver. Remove the front
panel assembly toward the front.
Fig.4
Fig.5
Fig.6
Fig.7
Fig.8-1
Fig.8-2
Front panel assembly
CN700 Micom board
Clamp
Regulator board Front panel assembly
CN104
C
CFront panel assembly
Micom board
CN700
D
a
Front panel assembly
b
Front panel assembly
bFront panel assembly

1-10 (No.MB013)
3.1.3 Removing the cassette mechanism control board
(See Fig.9)
• Prior to performing the following procedure, remove the metal
cover.
(1) Disconnect the card wire from connector CN32 on the cas-
sette mecha control board.
(2) Remove the two screws Eon the left side of the body.
(3) Move the cassette mecha control board upward to release
the joint c.
(4) Disconnect the wire from connector CN31 on the inside of
the cassette mecha control board.
Fig.9
3.1.4 Removing the cassette mechanism assembly
(See Fig.10, 11)
• Prior to performing the following procedure, remove the metal
cover and the cassette mechanism control board.
(1) Disconnect the card wire from connector CN791 on the mi-
com board.
(2) Disconnect the wire from connector on the Motor board in
the rear of the cassette mechanism assembly.
(3) Remove the two screws Cand the two screws Fon top of
the body.
Move the rear side of the cassette mechanism assembly
upward and remove.
(The chassis bkt. comes off with the cassette mechanism
assembly).
Fig.10
Fig.11
CN31
E
E
c
CN32
Cassette mecha
control board
C
C
F
F
Front panel assembly
Cassette mechanism assembly
Micom board
CN791
Cassette mechanism assembly
CN750
Micom board
Motor board
connector

(No.MB013)1-11
3.1.5 Removing the tuner assembly
(See Fig.12)
• Prior to performing the following procedure, remove the metal
cover.
(1) Disconnect the card wire from the tuner assembly.
(2) Remove the two screws Gfrom the rear panel on the back
of the body.
Fig.12
3.1.6 Removing the rear cover/ rear panel
(See Fig.13 ~ 15)
• Prior to performing the following procedure, remove the metal
cover.
Reference:
The rear panel comes off with the tuner assembly. Remove the
tuner assembly if necessary.
(1) Remove the three screws Hattaching the rear cover on the
back of the body.
(2) Remove the three screws Iattaching the rear panel on the
back of the body.
(3) Release the two joints don the right and left bottom of the
rear panel.
Fig.13
Fig.14
Fig.15
G
Card wire
Tuner assembly
Rear panel
Rear panel
Rear cover
I
I
HH
H
Rear panel
d
Rear panel
d

1-12 (No.MB013)
3.1.7 Removing the micom board (See Fig.16, 17)
• Prior to performing the following procedure, remove the metal
cover and the rear panel.
(1) Disconnect the card wire from connector CN700, CN790
and CN791 on the micom board.
(2) Disconnect the wire from connector CN750 and CN760 on
the micom board.
(3) Disconnect the wire from connector on the Motor board in
the cassette mechanism assembly.
(4) Remove the three screws Jattaching the micom board on
the right side of the body.
(5) Disconnect connector CN761 and CN762 on the micom
board from the heat sink board outward.
(6) Disconnect the card wire from connector CN765 on the un-
derside of the micom board.
Fig.16
Fig.17
3.1.8 Removing the regulator board
(See Fig.18)
• Prior to performing the following procedure, remove the metal
cover and the rear panel.
(1) Remove the two screws Kon the left side of the body.
(2) Disconnect connector CN103 on the regulator board from
the heat sink board outward.
(3) Disconnect the wire from connector CN100, CN101,
CN102 and CN104 on the regulator board respectively.
Fig.18
CN765
CN700 CN791 CN790
CN750
CN760
JJ J
CN762 CN761
Micom board
Cassette mechanism assembly
CN750
Micom board
Motor board
connector
K
KCN103
CN104
CN102
CN101
CN100
Regulator board

(No.MB013)1-13
3.1.9 Removing the heat sink board
(See Fig.19, 20)
• Prior to performing the following procedure, remove the metal
cover, the rear panel and the micom board/ regulator board.
(1) Release the wire from the clamp on the heat sink board.
(2) Remove the four screws L.
(3) Move the heat sink board upward to release from the main
chassis at the two joints e.
(4) Remove the two screws Mand the two screws Nattaching
the heat sink.
Fig.19
Fig.20
L
L
L
e
e
Heat sink board
Clamp
L
M
N
Heat sink
Heat sink board

1-14 (No.MB013)
3.1.10 Removing the power transformer assembly
(See Fig. 21, 22)
• Prior to performing the following procedure, remove the metal
cover, the rear panel, the micom board/ regulator board and
heat sink board.
(1) Release the wire from the three clamps on the main chas-
sis and cut the band.
(2) Remove the four screws Oattaching thepower transformer
assembly.
Fig.21
Fig.22
3.1.11 Removing the fan
(See Fig.23)
• Prior to performing the following procedure, remove the metal
cover; the rear panel, and the micom board/ regulator board/
heat sink board.
(1) Remove the two screws Pattaching the fan.
(2) Release the wire from the clamp.
Fig.23
Clamp
Power transformer assembly Band
Power transformer assembly
OO
O
O
Fan
Clamp
P

(No.MB013)1-15
3.1.12 Removing the 5 CD changer mechanism assembly
(See Fig.24 ~ 30)
• Prior to performing the following procedure, remove the metal
cover, the cassette mechanism control board, the cassette
mechanism assembly, the front panel assembly, the rear pan-
el, and the micom board/ regulator board/ heat sink board.
(1) Release the wire extending from the power transformer
from the three clamps in the rear of the main chassis.
(2) Disconnect the card wire from the servo control board in
the CD changer mechanism assembly.
(3) Remove the four screws Qattaching the main chassis on
the right and left sides, and detach the main chassis up-
ward.
(4) Remove the two screws Rin the rear of the CD changer
mechanism assembly and remove the two screws Son the
bottom. Remove the CD changer from the bottom chassis.
(5) Remove the two screws Tattaching the CD bkt.(F).
(6) Remove the two screws Uattaching the CD bkt.(R).
Fig.24
Fig.25
Fig.26
Fig.27
Main chassis
Clamp
Main chassis
CD changer mechanism assembly
Card wire
Servo control board Q
Main chassis
CD changer mechanism assembly
Card wire
Q
CD changer mechanism assembly
RR

1-16 (No.MB013)
Fig.28
Fig.29
Fig.30
S
CD changer mechanism assembly
T
CD changer mechanism assembly
CD BKT(F)
U
CD BKT(R)
CD changer mechanism assembly

(No.MB013)1-17
3.2 Front panel assembly
• Prior to performing the following procedure, remove the metal
cover, the cassette mechanism control board, the cassette
mechanism assembly and the front panel assembly.
3.2.1 Removing the front assembly section
(See Fig.31)
(1) Remove the four screws Vattaching the front assembly
section.
Fig.31
V
V
V
V
Front assembly section
Front panel assembly

1-18 (No.MB013)
3.2.2 Removing the switch board
(See Fig.32, 33)
• Prior to performing the following procedure, remove the front
assembly section.
(1) Pull out the volume control knob on the front side of the
front assembly section.
(2) Disconnect the card wire from connector CN510 on the
switch board.
(3) Remove the six screws Wattaching the switch board.
Fig.32
Fig.33
3.2.3 Removing the LED board
(See Fig.34)
• Prior to performing the following procedure, remove the front
assembly section.
(1) Disconnect the card wire from connector CN551 and
CN552 on the LED board.
(2) Remove the six screws Xattaching the LED board.
Fig.34
Volume knob
Front assembly section
WW
Front assembly section
LED board
Switch board
CN510
XX
CN552
CN551
Front assembly section
LED board
Switch board

(No.MB013)1-19
3.2.4 Removing the FL display
(See Fig.35 ~ 37)
• Prior to performing the following procedure, remove the front
assembly section and the LED board.
(1) Remove the four screws Yattaching the lens holder. Re-
move the lens holder, the cover sheet and the LED lens re-
spectively.
(2) Pull out the FL display from the front assembly section.
Fig.35
Fig.36
Fig.37
3.2.5 Removing the headphone board
(See Fig.38)
(1) From the back of the front panel, remove the spacer setting
the wire.
(2) Remove the screw Zattaching the headphone board.
Fig.38
Y
Y
Y
Y
Front assembly section
Lens holder
Cover sheet
LED lens
FL display section
Front assembly section
Z
Spacer
Headphone board

1-20 (No.MB013)
3.3 CD changer mechanism
3.3.1 Removing the tray assembly
(See Fig.1 ~ 5)
(1) Remove the two screws Afrom the top cover and release
the two joints aon both sides of the body.
(2) Remove the top cover with the two rods attached to the top
cover and lifter assembly respectively.
(3) Remove the open det lever on the left side of the body.
(4) Push part b of the slide (R) assembly on the right side of
the body to unlock the tray assembly. Draw out the trays to-
ward the front.
Attention:
The tray can be locked if all tray assemblies are at-
tached.
(5) From top of the body, move the stopper tab c in the direc-
tion of the arrow and release. Pull out the tray assemblies
from the body.
Caution:
Remove the tray assembly from top tray 5 in order.
Attention:
When reattaching the sub tray of the tray assembly, or when
removing the CD remaining inside, refer to another section.
Fig.1
Fig.2
Fig.3
Fig.4
Fig.5
Top cover
Lifter assembly
Rod
A
a
a
A
aRod Top cover
Lifter assembly
a
Open det leve
r
b
Tray assembly
(Tray 5)
c