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SERVICE MANUAL
DVD DIGITAL THEATER SYSTEM
12
2003
MB141
TH-A25
Area suffix
J ----------------------------- U.S.A.
C -------------------------- Canada
SOUND
VOLUME
DVD DIGIT CINEMA SYSTEM TH-A25
AL
STANDBY
STANDBY/ON
SOURCE
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
COPYRIGHT © 2003 VICTOR COMPANY OF JAPAN, LIMITED No.MB141
2003/12
SPECIFICATION
Center unit (XV-THA25)
Amplifier Front/Center/Rear 30 W per channel, min. RMS, driven into 6 at 1 kHz, with no more than 10% total harmonic distortion
Subwoofer 55 W, min. RMS, driven into 3 at 100 Hz, with no more than 10% total harmonic distortion
Audio Audio input sensitivity/Impedance (at 1 kHz)
Analog input AUX ("AUDIO IN") 500 mV/47 k
Signal-to-Noise Ratio 68 dB
Digital input* DIGITAL IN (OPTICAL) -24 dBm to -14.5 dBm (700 nm ±50 nm)
* Corresponding to Linear PCM, Dolby Digital, and DTS Digital Surround (with sampling frequency-32 kHz, 44.1 kHz, 48
kHz)
Video Color System NTSC
Horizontal Resolution 480 lines
Output Level VIDEO OUT (Composite) 1.0 V(p-p)/75
S-VIDEO (Y):1.0 V(p-p)/75
(C):0.286 V(p-p)/75
COMPONENT Y 1.0 V(p-p)/75
VIDEO OUT PB/PR 0.7 V(p-p)/75
Tuner Tuning Range FM 87.50 MHz - 108.00 MHz
AM 530 kHz - 1 710 kHz
Usable Sensitivity FM 8.0 dBf (0.9 µV/75 )
AM loop antenna 650 µV/m
General Readable Discs DVD VIDEO, Video CD, Super Video CD, Audio CD, CD-R/RW (Audio CD,
Video CD, Super Video CD, MP3, JPEG), DVD-R/RW (Video format)
Power Requirements AC 120 V , 60 Hz
Power Consumption 110 W (at operation) 2 W (in standby mode)
Dimensions (W × H × D) 360 mm × 65 mm × 404 mm (14 3/16 in. × 2 9/16 in. × 15 15/16 in.)
Mass 6.3 kg (13.9 lbs)
Subwoofer (SP-WA25)
Speaker 15 cm (5 15/16 in.) Bass-reflex, magnetically shielded
Power Handling Capacity 55 W
Impedance 3 (min)
Frequency Range 30 Hz to 200 Hz
Dimensions (W × H × D) 210 mm × 382 mm × 338 mm (8 5/16 in. × 15 1/16 in. × 13 5/16 in.)
Mass 6 kg (13.3 lbs)
Satellite Speakers (SP-XTHA25)
Speaker 8 cm (3 3/16 in.) Bass-reflex, magnetically shielded
Power Handling Capacity 30 W
Impedance 6 (min)
Frequency Range 80 Hz to 20 kHz
Dimensions (W × H × D) 105 mm × 114 mm × 116 mm (4 3/16 in. × 4 1/2 in. × 4 5/8 in.)
Mass 640 g (1.5 lbs)
Designs & specifications are subject to change without notice.
1-2 (No.MB141)
SECTION 1
PRECAUTION
1.1 Safety Precautions
(1) This design of this product contains special hardware and voltmeter.
many circuits and components specially for safety purpos- Move the resistor connection to each exposed metal
es. For continued protection, no changes should be made part, particularly any exposed metal part having a return
to the original design unless authorized in writing by the path to the chassis, and measure the AC voltage across
manufacturer. Replacement parts must be identical to the resistor. Now, reverse the plug in the AC outlet and
those used in the original circuits. Services should be per- repeat each measurement. Voltage measured any must
formed by qualified personnel only. not exceed 0.75 V AC (r.m.s.). This corresponds to 0.5
mA AC (r.m.s.).
(2) Alterations of the design or circuitry of the product should
AC VOLTMETER
not be made. Any design alterations of the product should (Having 1000
not be made. Any design alterations or additions will void ohms/volts,
the manufacturers warranty and will further relieve the or more sensitivity)
manufacture of responsibility for personal injury or property
damage resulting therefrom. 0.15 F AC TYPE
Place this
(3) Many electrical and mechanical parts in the products have probe on
special safety-related characteristics. These characteris- each exposed
tics are often not evident from visual inspection nor can the 1500 10W metal part.
protection afforded by them necessarily be obtained by us-
ing replacement components rated for higher voltage, watt- Good earth ground
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 1.2 Warning
are identified by shading on the schematics and by ( ) on (1) This equipment has been designed and manufactured to
the Parts List in the Service Manual. The use of a substitute meet international safety standards.
replacement which does not have the same safety charac- (2) It is the legal responsibility of the repairer to ensure that
teristics as the recommended replacement parts shown in these safety standards are maintained.
the Parts List of Service Manual may create shock, fire, or (3) Repairs must be made in accordance with the relevant
other hazards. safety standards.
(4) It is essential that safety critical components are replaced
(4) The leads in the products are routed and dressed with ties, by approved parts.
clamps, tubings, barriers and the like to be separated from (5) If mains voltage selector is provided, check setting for local
live parts, high temperature parts, moving parts and/or voltage.
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 1.3 Caution
that they have been returned to normal, after reassem- Burrs formed during molding may be left over on some parts
bling. of the chassis.
Therefore, pay attention to such burrs in the case of pre-
(5) Leakage shock hazard testing forming repair of this system.
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, 1.4 Critical parts for safety
headphone jack, control shafts, etc.) to be sure the product
is safe to operate without danger of electrical shock.Do not In regard with component parts appearing on the silk-screen
use a line isolation transformer during this check. printed side (parts side) of the PWB diagrams, the parts that are
· Plug the AC line cord directly into the AC outlet. Using a printed over with black such as the resistor ( ), diode ( )
"Leakage Current Tester", measure the leakage current and ICP ( ) or identified by the " " mark nearby are critical
from each exposed metal parts of the cabinet, particular- for safety. When replacing them, be sure to use the parts of the
ly any exposed metal part having a return path to the same type and rating as specified by the manufacturer.
chassis, to a known good earth ground. Any leakage cur- (This regulation dose not Except the J and C version)
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, 1,000 per volt or more sensitivity
in the following manner. Connect a 1,500 10W 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
(No.MB141)1-3
1.5 Preventing static electricity
1.5.1 Grounding to prevent damage by 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.
1.5.2 About the earth processing for the destruction prevention 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) 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.
(caption)
Anti-static wrist strap
Conductive material
(conductive sheet) or iron plate
1.5.3 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 pick-
up 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 tester's internal power source can easily
destroy the laser diode.
1.5.4 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) Remove solder of the short lands on the flexible wire after replacing the optical pickup. For specific details, refer to the replace-
ment 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 wire 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.
1.5.5 Attention when traverse unit is decomposed
*Please refer to "Disassembly method" in the text for the DVD pickup.
· Apply solder to the short circuit points before the flexible wire is disconnected from the connector on the DVD pickup.
(If the flexible wire is disconnected without applying solder, the DVD pickup may be destroyed by static electricity.)
· In the assembly, be sure to remove solder from the short circuit points after connecting the flexible wire.
1-4 (No.MB141)
1.6 Importance administering point on the safety
Caution: For continued protection against risk of
fire, replace only with same type T1.25A/250V for
AFS1, T5A/125V for AFS2, T160mA/250V for AFS3
and T80mA/250V for AFS4. This symbol specifies
type of fast operating fuse.
Precaution: Pour eviter risques de feux, remplacez
le fusible de surete de AFS1 comme le meme type
que T1.25A/250V, et T5A/125V pour AFS2, et
T160mA/250V pour AFS3, et T80mA/250V pour AFS4.
^
Ce sont des fusibles suretes qui functionnes rapide.
(No.MB141)1-5
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
This service manual does not describe SPECIFIC SERVICE INSTRUCTIONS.
1-6 (No.MB141)
SECTION 3
DISASSEMBLY
3.1 Main body section
3.1.1 Removing the top cover
(See Figs.1 and 2)
(1) From the both sides of the main body, remove the four
Top cover
screws A attaching the top cover. (See Fig.1)
(2) From the back side of the main body, remove the four
screws B attaching the top cover. (See Fig.2)
(3) Take out the top cover in the upward direction while ex-
tending the lower sections of the top cover in the direction
of right and left.
A A
Fig.1
B
Top cover Rear panel
Fig.2
(No.MB141)1-7
3.1.2 Removing the tray door
(See Figs.3 to 6)
· Prior to performing the following procedures, remove the top
cover. DVD
· The following procedures are performed in the case of power top cover C
on.
(1) From the front side of the main body, push the disk open C
bottom and eject the disc tray. (See Fig.3)
(2) Release the joints a in the upward direction and take out
the tray door. (See Fig.3)
NOTE:
The following procedures are performed in the case of power
off.
(1) From the top side of the main body, remove the four
screws C attaching the DVD top cover. (See Fig.4) DVD
mechanism
(2) Take out the disc tray in the direction of the arrow while assembly
lifting the section b. (See Fig.5)
(3) Release the joints a in an upward direction and take out Fig.4
the tray door. (See Fig.6)
(4) Remove the four screws D attaching the DVD mecha-
nism assembly. (See Fig.6)
(5) Disconnect the wires from the connectors AJ1, AJS1 and
PCN1 on the DVD mechanism assembly, and take out
the DVD mechanism assembly. (See Fig.6) Claws c
(6) Push in the disc tray while lifting the section b. (See
Fig.5)
Reference:
· When pushing in the disc tray, push it until the posi- DVD mechanism
tion of the claw c. (See Fig.5) assembly
(7) Attach the DVD top cover with the four screws C to the
DVD mechanism assembly.
Reference:
· Attaching method of the DVD mechanism assembly Section b
refers to the section 3.1.3.
Joints a Tray door Disk open button Disk tray
Fig.5
D D
AJ1
PCN1
Fig.3
AJS1
D
DVD Joints a
mechanism
assembly
Tray door
Fig.6
1-8 (No.MB141)
3.1.3 Removing the DVD mechanism assembly
(See Fig.7)
· Prior to performing the following procedures, remove the top
cover and tray door.
(1) From the top side of the main body, remove the four screws
D attaching the DVD mechanism assembly. D D
(2) Disconnect the wires from the connectors AJ1, AJS1 and JS1
PCN1 on the DVD mechanism assembly, and take out the
DVD mechanism assembly.
PCN1
AJS1
D
DVD
mechanism
assembly
Fig.7
3.1.4 Removing the front panel assembly (See Figs.8 and 9)
· Prior to performing the following procedures, remove the top
cover and tray door. Front panel assembly F
(1) From the top side of the main body, disconnect the card
wire from the connector UW4 on the function board. (See
Fig.8)
(2) From the bottom side of the main body, remove the four
screws E attaching the front panel assembly. (See Fig.9)
(3) From the both sides of the main body, remove the two
screws F attaching the front panel assembly. (See Fig.9)
(4) Release the joints d in forward direction and take out the
front panel assembly. (See Fig.9)
E
Joint d
Fig.8
3.1.5 Removing the tuner pack
Front panel assembly UW4
(See Figs.8 and 10)
· Prior to performing the following procedures, remove the top
cover.
(1) From the top side of the main body, disconnect the card
wire from the connector VW4 on video board. (See Fig.8)
(2) Remove the screw G attaching the tuner pack. (See Fig.8)
(3) From the back side of the main body, remove the screw H
attaching the tuner pack. (See Fig.10)
3.1.6 Removing the fan motor (See Figs.8 and 10) Function
board
· Prior to performing the following procedures, remove the top
cover. G
(1) From the top side of the main body, disconnect the fan
motor wire from the connector UW9 on the function board. Tuner
(See Fig.8) pack
(2) From the back side of the main body, remove two screws J
VW4
attaching the fan motor. (See Fig.10)
Fan motor UW9 Video board
Fig.9
J Rear panel H
Fan motor
Fig.10
(No.MB141)1-9
3.1.7 Removing the rear panel
(See Fig.11)
· Prior to performing the following procedures, remove the top
cover and fan motor. L Rear panel K Power cord
(1) From the back side of the main body, remove the power
cord from the rear panel in the direction of the arrow.
(2) Remove the screw H, two screws K, five screws L three
screws M and attaching the rear panel.
(3) Take out the rear panel.
M H
Fig.11
3.1.8 Removing the video board
(See Fig.12)
· Prior to performing the following procedures, remove the top
cover, fan motor and rear panel.
(1) From the top side of the main body, disconnect the power
cord from the connector ACW1 on the main board.
(2) Disconnect the card wire from the connector VW4 on the
video board. UW7
(3) Disconnect the video board from the connector UW7 and
UW8
UW8 on the function board, and turn over the video board.
(4) From the reverse side of the video board, disconnect the
card wire from the connector VW3 on the video board, and
take out the video board.
ACW1
Reference:
· Remove the tie band as required.
Tie band
Function board
Video board VW3 VW4 Power cord
Fig.12
3.1.9 Removing the function board
(See Fig.13)
· Prior to performing the following procedures, remove the top
UW6 UW4 PCN1 DVD mechanism
cover, fan motor, rear panel and video board. assembly
(1) From the top side of the main body, disconnect the wires
from the connector PCN1 on the DVD mechanism
assembly.
(2) Disconnect the card wire from the connector UW4 and
UW6 on the function board.
(3) Remove the screw N attaching the function board.
(4) Disconnect the function board from the connector CW5,
CW6 and CW7 on the main board. N
CW5
CW6
CW7
Function board Main board
Fig.13
1-10 (No.MB141)
3.1.10 Removing the main board
(See Fig.14)
· Prior to performing the following procedures, remove the top
cover, tray door, DVD mechanism assembly, fan motor, rear Power trans Q Wire clamp
panel, video board and function board.
(1) From the top side of the main body, remove the nine
screws P attaching the main board.
(2) Disconnect the wires from the connectors ACW2, ACW3, Q
ACW4 and ACW5 on the main board and take out the main
board.
ACW4
ACW2
Reference: P
· When attaching the screw P, attach the wire clamp together
with it. ACW3
· After connecting the wire to the connector ACW2, bundle the ACW5
wire using the wire clamp.
P
3.1.11 Removing the power trans
(See Fig.14)
· Prior to performing the following procedures, remove the top
cover, tray door, DVD mechanism assembly, fan motor, rear P
panel, video board and function board. Fig.14
(1) From the top side of the main body, disconnect the wires
from the connectors ACW2, ACW3, ACW4 and ACW5 on
the main board.
(2) Remove the four screws Q attaching the power trans.
(No.MB141)1-11
3.2 Front panel assembly section
3.2.1 Removing the front board (See Fig.15)
· Prior to performing the following procedures, remove the top
cover, tray door and front panel assembly. Front board UCW13 Wire Power SW board
(1) From the back side of the front panel assembly, remove the
five screws R attaching the FRONT board.
(2) Disconnect the wire from the connector UCW13 on the
front board.
(3) Take out the front board from the front panel assembly.
3.2.2 Removing the power SW board
(See Fig.15)
· Prior to performing the following procedures, remove the top R S
cover, tray door, front panel assembly and front board.
(1) Remove the screw S attaching the power SW board. Fig.15
(2) Take out the power SW board from the front panel
assembly.
1-12 (No.MB141)
SECTION 4
ADJUSTMENT
This service manual does not describe ADJUSTMENT.
(No.MB141)1-13
SECTION 5
TROUBLESHOOTING
5.1 MAIN
5.1.1 POWER
NO NO
Check for VCC(5V) Check for Input voltage
Check for circuit at Sub Trans
at FRONT PCB at POWER PCB
;PBD2, PT1, AFS3(Fuse)
;pin #17,46,72,90 of UIC1 ;AIC1(7805)
YES
YES
Replace AIC1
NO Check normal Voltage NO Replace AZD1
Check for power-sense(5V)at FRONT PCB at POWER PCB Check resistant from GND
;pin #77 of UIC1 AZD1 (5.1V, 1/2W) to pin #77 of MICOM(UIC1)
if the short(0 ohm),to replace
Micom(UIC1)
YES YES
Check pattern from VCW7
When power on for FRONT PCB to pin#77 of UIC1
Check for High Voltage(5V) at"M"com
;pin#74 of UIC1
NO
Replace Micom(UIC1)
YES
Check low Voltage(0V)
at EXPAND IC (M66010)
;pin#32 of UIC500
NO If High Voltage (5V), check for Circuit protection
Check connector wire Ass'y of power
YES P/T - MAIN PCB(7P,ACW3)
MAIN PCB (8P,PW3)
Check for connector from DSP PCB to FRONT PCB
;VCW7
1-14 (No.MB141)
5.1.2 OUTPUT
NO
Check voltage at Main PCB
Check Connector PW1
; VM, VL
Check ABD2,4
YES
NO
Check Audio channel at CW5 Check Voltage for CW7
for input:5.1 channel Audio signal ; 12V
YES
Check signal for FR/FL/C/W/RL/RR NO Check circuit for AMP channel
at MAIN PCB ;Out ports of FIC6, IC7, RIC5
Reference to NEXT page
; "A" position
YES
NO Check circuit for Speak Relay
Check voltage for CW7(SPK Relay)
;High(5V)
Check Q4,Q5
(No.MB141)1-15
5.1.3 Protection(When High Voltage at Protectiion port)
5.1.3.1 In this case "LOW" for, Base port of Q12(R2003 TR) at MAIN PCB
Check voltage for IC4 NO
-12V Check circuit for voltage(-12V)
YES
Check Voltage NO
for Main AMP of Main PCB Check ABD 2,4
VM, VL
YES
"A"
NO
Check DC Voltage for Speaker port Check circuit for DC Voltage
YES
Check the parts is normal?
;ZD6,ZD5(3.9V)
;R33,R36(27K)
R34,R37 (150 Ohm)
YES
Check normal condition for Q15(C945) NO
;temperature-sense S/W be operated in the Power Trans Replace P/T, Q15
is Turn on
YES
NO Check circuit for
Check electric potention for PBD 1, ABD1 , PD3 at DVD Power PCB
Diode behind position
1-16 (No.MB141)
5.1.3.2 In this case "LOW" for Base of Q13(A733) at Main PCB
Check the Turn on for channel of Q35(C945)
Check circuit for channel(Turn on)
according feedback "A"position of
previous page
5.1.3.3 Check the Connector Wire Ass'y Connectin of each PCB
;DVD MECHA - Main PCB (8P,PW3)
;POWER TRANS - Main PCB (ACW3)
(No.MB141)1-17
5.2 DVD Servo parts
5.2.1 Initial operation after power ON
POWER ON
N Tray close operation.
Is Tray closed?
about 3sec.
Y N
Y
3 Pick up head initial position. Is Tray closed?
4 Disc present or not Stop Close operation.
Wait Open Command from MPEG
N
Laser Off
Disc present
Monitor Display=NO DISC
Y
CD or DVD judgement
DVD CD
DVD single or CD or CDRW
Dual layer judgement judgement
Single Dual CD CDRW
DVD single DVD Dual CD CDRW
initial setting initial setting initial setting initial setting
To Each disc playback
(DVD Dual) (DVD single)
1-18 (No.MB141)
5.2.2 Play operation
Play
Repeat Change
5 Disc Motor forced accelleration
seveal times Disc Type
Focus Seach
Is focus servo 6
on?
Track servo ON 7
CLV servo ON 8
Automatic Adjustment
Automatic Adjustment is done once
when the disc is replaced
Read TOC
Search Picture appears
(No.MB141)1-19
5.2.3 PickUp Head Initial Position
PickUp Head Initial Position
(1) 1. Move Pick Up Head to inner direction until pin5 of MJ4="L"
(2) 2. If pin5 of MJ4="L", then move Pick Up Head to outer direction for a short time.
(3) 3. Turn On the Laser of Pick Up Head to judge that disc is present or not.
3
N Check
Does Pick Up Is pulse of 2.5 Y connection
Move to inner +-2.5V developed
between PCB
direction? at pin3,4 of MJ4?
and MECHA
N
Y Check
Is pulse of 2.5
Y peripheral
+-2.5V developed
circuit of SIC1
at pin13 of SIC1
and DRIC1
N Check BUS
line between
SIC1 and MIC1
Does Pick Up
N Is pin5 of MJ4 = N Check
Move to out
"L" appeared? connection
direction again?
between PCB
Y and MECHA
Y
Check line between SIC1
and MJ4
OK
Does Laser Turn
On?
N
Check voltage at Y
pin8 of RCN1 is Replace Pick Up Head
about 2.5V?
N
Check BUS line between RIC1 and
SIC1,SIC1 and MIC1
1-20 (No.MB141)
5.2.4 Disc Presence/Absense Judgment
4
Disc Presence Judgment
Turn On Laser
Does lens move Check
N Is focus search Y
with UP/DOWN
full stroke in focus
voltage developed peripheral
at pin 11 of SIC1 circuit of DRIC1
direction?
N Check BUS
line between
Y SIC1 and MIC1
Check PI
(pin36 of RU1) No signal Y
signal and FE No Disc OK
(pin42 of RIC1)signal
N
Check connection between RIC1 and RCN1.
Normal Check BUS line RIC1and SIC1.
Check RIC1
Disc is presence
(No.MB141)1-21
5.2.5 Disc Motor Does Not Rotate
5
Disc Motor Does Not Rotate
Is Voltage of 0V Y
developed at Check peripheral circuit of DRIC1
pin15 of SIC1
N
Check peripheral circuit of SIC1.
Check SIC1
5.2.6 Focus Servo does not Work
6
Focus Servo does not Work
Are FE(pin42 of RIC1) N Check peripheral circuit of SIC1 and
and PI(pin36 of RIC1) RIC1
normal?
Y
Check peripheral circuit of SIC1 and
RIC1 Check Connection between PCB and
MECHA
Check peripheral circuit of DRIC1 (CD-RW)
(CD) (DVD Single) (DVD Dual)
1-22 (No.MB141)
5.2.7 Tracking Servo Does Not Work
7
Tracking Servo Does not Work
Check Voltage of N
PI(pin36 of RIC1) is Disc Judgment Error
normal
Y
Is TE(pin41 of RIC1) N
Check peripheral circuit or RIC1
normal?
Y
Change PickUp or RIC1
Check peripheral circuit or RCN1 and
DRIC1
Change SIC1
Check connection between PCB
and MECHA
(CD) (CD-RW)
(DVD Single) (DVD Dual)
(No.MB141)1-23
5.2.8 CLV Servo Does Not Work
8
CLV Servo Does not Work
Y
Is XSRFIN(pin2 of SIC1) Check peripheral circuit of SIC1
normal?
N
Check peripheral circuit of DRIC1
Y
Is RF(pin21 of RCN1)
normal? Check peripheral circuit of RIC1
N
Check connection between PCB
and MECHA
1-24 (No.MB141)
5.3 DVD MPEG Parts
5.3.1 Initial operation after NO
POWER ON
WAIT
N N Check Reset Voltage at 24pin of
2 LOGO ON U13
Y
"NO DISC" DISPLAY N Check Servo parts and MPEG
(in time of absence) ATAPI Line
Y
Loading N Check Servo spindle motor
(in time of presence) parts
Y
N Check
Play Pick up Lens and Pick up Flat
Cable
Y
Audio out/ in N
3
normal
Y
OK
(No.MB141)1-25
5.3.2 Logo operation
2
Check Voltage
Check 27MHZ crystal
of REG2 2.85V
FIg.1
REG3 3.50V
Y
Check 114MHZ(pin 102
of U13)
Fig.1
Y
N Check Video signal of
Video OK
VQ1,VQ3,VQ4,VQ5,VQ6
Y
OK
5.3.3 Audio operation
3
Check Audio Digital signal N
Check NEW DSP Parts
at pin 33,36,37 of U13
Y
N
Audio out Check Main AMP parts
Y
OK
1-26 (No.MB141)
(No.MB141)1-27
VICTOR COMPANY OF JAPAN, LIMITED
AV & MULTIMEDIA COMPANY AUDIO/VIDEO SYSTEMS CATEGORY 10-1,1chome,Ohwatari-machi,Maebashi-city,371-8543,Japan
(No.MB141)
Printed in Japan
WPC
SCHEMATIC DIAGRAMS
DVD DIGITAL THEATER SYSTEM
TH-A25
CD-ROM No.SML200403
SOUND
VOLUME
DVD DIGITAL CINEMA S Y STEM TH-A25
STANDBY
STANDBY/ON
SOURCE
Area suffix
J ----------------------------- U.S.A.
C -------------------------- Canada
Since the printed circuit board of DVD was changed, the schematic diagram
and printed circuit boad which were changed are published.
Contents
Standard schematic diagrams ---------------------------------- 2-1
Printed circuit board ----------------------------------------------- 2-5
No.MB141BSCH
COPYRIGHT 2004 VICTOR COMPANY OF JAPAN, LTD. 2004/3
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.
(This regulation does not correspond to J and C version.)
< MEMO >
Standard schematic diagrams
RR1 4.7K(SD) PLL3(pin124) CLK SOURCE
SDRAM (MIC7) DECOUPLING CAPACITORS VCC33 1 CRSTAL OSC VCC33 VCC33 VCC33 VCC33
VCC33 RR2 4.7K(SD) JJ1(SD) 0 DCLK INPUT
1.2K(OPEN)
1.2K(OPEN)
1.2K(OPEN)
1.2K(OPEN)
STXD PLL2 PLL1 PLL0 MULTI Frequency
PIN 1 PIN 3 PIN 9 PIN 14 PIN 27 PIN 43 PIN 49 RS232_DET 1 SERVO MCU TWS TSD1 TSD0 DEFAULT S-CHIP DEFAULT S-CHIP
2 DEBUG
MR4
MR5
MR6
MR7
SRXD 0 0 0 4.25 4.5 114.75 121.5
A5V 3 0 0 1 reserved 5 NA 135
4 HEADER bypass bypass
0 1 0 27 NA
BC1 BC2 BC3 BC4 BC5 BC6 BC7 5 0 1 1 3.75 4 101.25 108
0.1U 0.1U 0.1U 0.1U 0.1U 0.1U 0.1U 1 0 0 4.5 4.25 121.5 114.75 MR91
EGND 1 0 1 reserved 4.75 NA 128.25
1 1 0 3.5 5.5 94.5 148.5
RS232 CONNECTOR 2.54MM 1 1 1 4 6 108 162 ML4 CIM10
EGND MC3
MC4 1000P
1000P MC5
SBAD TP32 RFGND MC6 1000P
XFLAG0 TP1 SBAD 1000P
XFLAG1 FLAG0 TP2 SBAD MR10 3.3K
2 SBAD
XFLAG2 TP3 FLAG1 FEI MR11 3.3K
2 FEI
1.2K
1.2K
1.2K
1.2K
MR12