JVC THA-35 Service manual
SERVICE MANUAL
DVD DIGITAL CINEMA SYSTEM
TH-A35
TH-A35
STANDBY
ANDBY/ON
ST
Contents
Safety precautions --------------------------- 1- 2
Preventing static electricity ----------------- 1- 3
Important for laser products ---------------- 1- 4
DIGITAL
COMPACT
DIGITAL¥EX
SUPER VIDEO
PRO LOGIC
SURROUND
VOLUME
PHONES
DSPSORROUND
SOURCE
Area Suffix
J ........................ U.S.A.
C ........................ Canada
Disassembly method ------------------------ 1- 5
Description of major ICs -------------------- 1- 15
Wiring connection ---------------------------- 1- 20
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LTD.
No. 22020
Jun. 2003
TH-A35
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 manufacturer's 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 (
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 ser vice 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.
5. Leakage currnet check (Electrical shock hazard testing)
After re-assembling the product, always perfor m 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, 1,000 ohms per volt or
more sensitivity in the following manner. Connect a 1,500 10W resistor paralleled by a 0.15 F ACtype 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 meausre
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.).
) on the Parts List in the Service Manual. The use of a substitute replacement
AC VOLTMETER
(Having 1000
ohms/v
or more sensitivity)
0.15 F AC TYPE
1500 10W
olts,
Place this
probe on
each exposed
metal part.
Good earth ground
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.
!
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.
1-2
TH-A35
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.
1.1. Grounding to prevent damage by static electricity
Static electricity in the work area can destroy the optical pickup (laser diode) in devices such as DVD players.
Be careful to use proper grounding in the area where repairs are being performed.
1.1.1. Ground the workbench
1. 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.
1.1.2. Ground yourself
1. Use an anti-static wrist strap to release any static electricity built up in your body.
(caption)
Anti-static wrist strap
1M
Conductive material
(conductive sheet) or iron plate
1.1.3. Handling the optical pickup
1. 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.)
2. Do not use a tester to check the condition of the laser diode in the optical pickup. The testers internal power
source can easily destroy the laser diode.
1.2. 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. It is not possible to adjust the semi-fixed resistor that adjusts the laser power. Do not turn it.
1-3
TH-A35
Important for laser products
1. CLASS 1 LASER PRODUCT
2. CAUTION : Visible and invisible laser radiation when
open and interlock 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
defeated. It is dangerous to defeat the safety switches.
VARNING : Osynlig laserstrålning är denna del är öppnad
och spårren är urkopplad. Betrakta ej strålen.
VARO : Avattaessa ja suojalukitus ohitettaessa olet
alttiina näkymättömälle lasersäteilylle. Älä
katso säteeseen.
REPRODUCTION AND POSITION OF LABELS
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.
!
CAUTION
Please use enough caution not
to see the beam directly or touch
it in case of an adjustment or
operation check.
ADVARSEL : Usynlig laserstråling ved åbning, når
sikkerhedsafbrydere er ude af funktion.
Undgå udsættelse for stråling.
ADVARSEL : Usynlig laserstråling ved åpning, når
sikkerhetsbryteren er avslott. Unngå
utsettelse for stråling.
CLASS 1 LABEL
CLASS 1
LASER PRODUCT
CLASS 1
LASER PRODUCT
WARNING LABEL
1-4
TH-A35
Disassembly method
Commence disassembly of this set by removing the main units and then proceed to the components and
assemblies inside the units.
< MAIN BODY >
Removing the cabinet top
Removing the tray Door
Removing the cabinet front
Removing the TUNER and panel rear
< CHAS, MAIN ASSEMBLY >
Removing the MPEG BOARD
Removing the MAIN BOARD
Removing FAN
Removing the Thermal - Regifer
Removing the VCD mechanism base assembly
Removing PWB, AMP
Removing Power , fruformer
2. PIN CONFIGURATION
< Front panel ASSEMBLY >
Removing the FRONT PWB & LED PWB
1-5
TH-A35
< MAIN BODY >
Removing the cabinet top
(See Fig.1)
1. Unscrew the 6 serew A
2. Lift the cabinet top by holding the two sides of it,
while moving it upward and backward.
Removing the Tray Door
(See Fig.2)
1. Eject the disc tr ay.
(Rotate the screw B counter - clockwise if no supply)
2. Lift up the tr ay door in the indicated direction
Rear cover
Top cover
Fig.1
CLASS 1
LASER PRODUCT
Right coverLeft cover
1-6
B
Fig.2
Removing the cabinet front
(See Fig.3)
[Caution] You must ensure the TRAY door isn't it's place
before you remove the panel front from body.
1. Unscrew the serew 2 C & 2 D.
2. Pull the panel front toward yourself while pressing 5
stoppers to disengage.
STOPPER
TH-A35
D
D
STOPPER
C
STOPPER
STOPPER
STOPPER
C
Removing the TUNER and panel rear
(See Fig.4)
1. Unserew the screw H form mpeg board unit and unit
and main board unit.
2. Unserw the screw K form body.
3. Take the supply cord out of panel rear.
4. Remove teh panel rear with tuner .
< CHAS, MAIN ASSEMBLY >
Removing the MPEG BOARD
(See Fig.5)
[Caution] Mpeg board may be taken out only when the
panel rear and Tunet have been taken away.
Fig.3
K
Fig.4
H
CLASS 1
LASER PRODUCT
1. Pull the cable connetor mpeg board.
2. Unscrew the screw M.
3.Separate the mpeg board from main board
vertically.
M
Fig.5
1-7
TH-A35
Removing the MAIN Board
( See Fig.6 & 7 )
[Caution] Main board may be taken out when the
mpeg board has been taken away.
1. Force the PCB spacer Q to exit the holes of main
board.
2. Unscrew the screw P.
3.Unscrew the screw R then you can remove the main
board with heat sink.
4.Untie or open connecters to power transformer,
PWB,AMP, DVD - mech.
P
Q
Fig. 6
Fig. 7
Removing FAN
(See Fig.8)
1.Unscreew 3 screws R with HOLDER, pull
out connector from PWB, main.
2.Unscrew 2 screws S from HLDR.
Removing the Thermal - Regifer
(See Fig.9)
1.Unscreew the screws though power IC and
thermal- HOLDER.
2.Pull wire of thermal - register from PWB main.
R
PULL
S
Fig. 8
1-8
Fig. 9
Removing the CD mechanism base
assembly
(See Fig.10)
Prior to performing the following procedure, remove
the cabinet front assembly.
1. Disconnect the harnesses from connector CN191
and CN192 on the main board and release them
from the cord stopper respectively.
2. Remove the four screws M attaching the
transformer assembly.
Removing PWB,AMP
(See Fig.11)
TH-A35
Fig. 10
1. Unscrew 4 screws L.
2. Pull out connecter from PWB, AMP.
Removing Power, frusformer
1. Unscrew 4 screws N
2. Untie wire connecter to PWB, MAIN.
(See Fig.11)
Fig. 11
1-9
TH-A35
<Front panel assembly>
Removing the front PWB & Led, PWB
(See Fig.12-13)
Prior to performing the following procedure, remove
the front panel assembly.
1. Remove the seven screws X and 3 screws
attaching the front panel board inside the front
panel assembly.
2. Push out KNOB, VOLUME through PWB, FR.
Fig. 12
Fig. 13
1-10
Description of major ICs
STK402-950 ( U701 ) : 5 channels AF power amplifier.
1. Pin layput
¥~«‹„ˇ4200
(unit:mm)
78.0
70.0
8.5
TH-A35
3.6
124
2.0
(12.0)
23x2.0=46.0
2. Block diagram
32.0
16.5
21.0
27.34.0
0.5
0.4
2.9
5.5
1-11
TH-A35
WM8770 ( U1 ) : 8-channel code c & volume control
1.
2. PIN CONFIGURATION
1-12
UPD78F0034A ( IC 401 ) : CPU
1.Block Diagram
TH-A35
1-13
TH-A35
2.Outline of Function
1-14
Description of major ICs
UPD 16315 ( IC904 ): VFD control ler / driver
1. BLOCK DIAGRAM
TH-A35
1-15
TH-A35
AK4112 ( U17 ) : Digital audio receiver
1. BLOCK DIAGRAM
2. Pin Layout ( AK4112BVF )
1-16
M29W160DB ( U12 ) : 16M Flash memory
.Pim layout
TH-A35
A15
A14
A13
A12
A11
A10 DQ14
A19
NC
RP
NC
NC
RB
A18
A17
1
A9
A8
W
12
M29W160DT
M29W160DB
13
A7
A6
A5
A4
A3
A2
24 25
A1
AI03844
48
37
36
A16
BYTE
V
SS
DQ15A±1
DQ7
DQ6
DQ13
DQ5
DQ12
DQ4
V
CC
DQ11
DQ3
DQ10
DQ2
DQ9
DQ1
DQ8
DQ0
G
V
SS
E
A0
1-17
TH-A35
2a3020 ( IC 701 ): DC - DC Regulator
2
SYNC
VIN
8
7
EN
Internal
Regulators
Shutdown
Comparator
0.7V
2.30/2.53V
Oscillator
40 / 400 KHz
Lockout
Comparator
Compensation
CLK
1uA
Slope
Current
Sense
Amp llfler
Current
Comparator
1.5V
1
SV
Q
S
R
Q
(
M2
10 ohm
SB
3
Vsw
4
GND
Frequency
Foldback
Comparator
LX171/LX1711 ( IC603 ) :
0.7V
1.22V
Error Am plifier
FB
5
gm = 630uM/Volt
Class-D mono power amplifier controller
VDD
25
IS-
CLOCK
RPWM
CPWM
EAOUT
EAIN
INAMPOUT
INP U T -
27
28
5
SYNC
OSC
CLK
6
14
13
9
ERROR AMP
8
PVDD
+
-
CURRENT SENSE
220m
COMP
6
SLEEP
10
VREF
UVLO
&
REFERE
V
NCE
5V
Reference
5V
Reference
FAULT
TIMER
OUTPUT
DRIVERS
1
V25
4
18
CN
PVDD
24
CP
26
P+
23
N+
22
&
21
N-
P-
20
CLK
SRQ
LOGIC
Q
1-18
INP U T +
MUT
7
INPUT AM
E
11
MUTE
P
MUX
TE
MU
FEEDBACK AMP
15
17
16
FAOUT
FBK-
FBK+
IR2110 ( IC603,604 ): Low and nigh side driver
Functional Block Diagram
V
DD
LEVEL
SHIFT
HIN
SD
LIN
V
RSQ
S
Q
R
SS
V
DD/VCC
LEVEL
SHIFT
V
DD/VCC
LEVEL
SHIFT
PULSE
GEN
TH-A35
V
UV
HV
DETECT
PULSE
FILTER
DETECT
DELAY
UV
Q
R
R
S
B
HO
V
S
V
CC
LO
COM
MC 14053B ( U21 ): digitally - controlled analog swith
Pin layout
YI
Y0
Z1
Z
Z0
INH
V
EE
V
SS
V
Y
X
X1
X0
A
B
C
DD
1-19
TH-A35
Wiring connection
1-20
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