JVC TH-A25 Diagram

MB141200312

SERVICE MANUAL

DVD DIGITAL THEATER SYSTEM

TH-A25

Area suffix

J ----------------------------- U.S.A.
C -------------------------- Canada

SOUND

VOLUME

STANDBY/ON

STANDBY

DVD DIGITAL CINEMA SYSTEM TH-A25

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 Ω at 1 kHz, with no more than 10% total harmonic distortion

Subwoofer 55 W, min. RMS, driven into 3 Ω 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 kΩ
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 samp ling 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 Ω

S-VIDEO (Y):1.0 V(p-p)/75 Ω

(C):0.286 V(p-p)/75 Ω

COMPONENT
VIDEO OUT

Tuner Tuning Range FM 87.50 MHz - 108.00 MHz

Usable Sensitivity FM 8.0 dBf (0.9 µV/75 Ω)

General Readable Discs DVD VIDEO, Video CD, Super Video CD, Audio CD, CD-R/RW (Audio CD,

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)

Speaker 15 cm (5 15/16 in.) Bass-reflex, magnetically shielded
Power Handling Capacity 55 W
Impedance 3 Ω (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)

Speaker 8 cm (3 3/16 in.) Bass-reflex, magnetically shielded
Power Handling Capacity 30 W
Impedance 6 Ω (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)

Y 1.0 V(p-p)/75 Ω
PB/PR 0.7 V(p-p)/75 Ω

AM 530 kHz - 1 710 kHz

AM loop antenna 650 µV/m

Video CD, Super Video CD, MP3, JPEG), DVD-R/RW (Video format)

Subwoofer (SP-WA25)

Satellite Speakers (SP-XTHA25)

Designs & specifications are subject to change without notice.

1-2 (No.MB141)

SECTION 1

PRECAUTION

1.1 Safety Precautions

(1) This design of th is product contains special hardw are 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 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 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 ( ) on
the Parts List in the Service Manual. The use of a substitute
replacement 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 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 reassem­bling.

(5) Leakage shock hazard testing

After reassembling the product, always perform 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, 1,000Ω per volt or more sensitivity
in the following manner. Connect a 1,500Ω 10W 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.).

AC VOLTMETER
(Having 1000
ohms/volts,
or more sensitivity)

0.15 F AC TYPE

Place this
probe on

1500 10W

Good earth ground

1.2 Warning

(1) This equipment has been designed and manufactured to

meet international safety standards.

(2) It is the legal resp onsibility 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 compone nts 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 pre­forming 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)

each exposed
metal part.

(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 dio de) 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 sh eet) 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 orig inal condition. (Refer to the text.)

(2) Do not use a tester to che ck 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 electri city.)

• 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

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 to p cover in the upward direction while ex-

tending the lower sections of the top cover in the directi on
of right and left.

Top cover

AA

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.

• The following procedures are performed in the case of power

on.
(1) From the front side of the main body, push the di sk open

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 th e 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)

(2) Take out the disc tray in the direction of the arrow w hile

lifting the section b. (See Fig.5)

(3) Release the joints a in an upward direction and take out

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

on the DVD mechanism assembly, and take out

PCN1

the DVD mechanism assembly. (See Fig.6)

(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 posi­tion of the claw c. (See Fig.5)

(7) Attach the DVD top cover with the four screws C to the

DVD mechanism assembly.

Reference:

• Attaching method of the DVD mechanism assembly
refers to the section 3.1.3.

Joints a Disk open buttonTray door

, AJS1 and

DVD
top cover

C

DVD
mechanism
assembly

C

Fig.4

Claws c

DVD mechanism
assembly

Section b

Disk tray

Fig.3

D

DVD
mechanism
assembly

Tray door

Fig.5

D

AJ1

PCN1

AJS1

D

Joints a

Fig.6

1-8 (No.MB141)

3.1.3 Removing the DVD mechanism assembly
(See Fig.7)

• Prior to performing the following procedures, remove th e top

cover and tray door.
(1) From the top side of the main body, remove the four screws

D attaching the DVD mechanism assembly.

(2) Disconnect the wires from the connectors AJ1

PCN1 on the DVD mechanism assembly, and take out the

DVD mechanism assembly.

, AJS1 and

D

D

JS1

PCN1

AJS1

3.1.4 Removing the front panel assembly (See Figs.8 and 9)

• Prior to performing the following procedures, remove th e top

cover and tray door.
(1) From the top side of the main bo dy, disconnect the card

wire from the connector UW4
Fig.8)

(2) From the bottom side of the main body, remo ve 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 ta ke out the

front panel assembly. (See Fig.9)

3.1.5 Removing the tuner pack
(See Figs.8 and 10)

• Prior to performing the following procedures, remove th e top

cover.
(1) From the top side of the main bo dy, disconnect the card

wire from the connector VW4
(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)

on the function board. (See

on video board. (See Fig.8)

DVD
mechanism
assembly

E

Front panel assembly

Fig.7

Front panel assembly

Fig.8

UW4

D

F

Joint d

3.1.6 Removing the fan motor (See Figs.8 and 10)

• Prior to performing the following procedures, remove th e top
cover.
(1) From the top side of the main body, disconnect the fan

motor wire from the connector UW9
(See Fig.8)

(2) From the back side of the main body, remove two screws J

attaching the fan motor. (See Fig.10)

on the function board.

Fan motor

J H

UW9

Fan motor

Video board

Fig.9

Rear panel

Fig.10

Function
board

G

Tuner
pack

VW4

(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.
(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.

L

Rear panel

K

Power cord

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, discon nect the power

cord from the connector ACW1

(2) Disconnect the card wire from the connecto r VW4

video board.

(3) Disconnect the video board from the connector UW7

on the function board, and turn over the video board.

UW8

(4) From the reverse side of th e video board, disconnect the

card wire from the connector VW3
take out the video board.

Reference:

• Remove the tie band as required.

3.1.9 Removing the function board
(See Fig.13)

• Prior to performing the following procedures, remove the top

cover, fan motor, rear panel and video board.
(1) From the top side of the main body, disconnect the wires

from the connector PCN1
assembly.

(2) Disconnect the card wire from the connector UW4

on the function board.

UW6

(3) Remove the screw N attaching the function board.
(4) Disconnect the function board from the connector CW5

and CW7 on the main board.

CW6

on the main board.

on the

and

on the video board, and

on the DVD mechanism

and

M

Fig.11

Function board

Video board

,

VW3 VW4

Fig.12

UW4UW6 DVD mechanism

PCN1

H

UW7

UW8

ACW1

Tie band

Power cord

assembly

N

1-10 (No.MB141)

CW5

CW6

CW7

Main boardFunction board

Fig.13

3.1.10 Removing the main board

A

A

A

(See Fig.14)

• Prior to performing the following procedures, remove th e top
cover, tray door, DVD mechanism assembly, fan motor, rear
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

and ACW5 on the main board and take out the main

ACW4

board.

Reference:

• When attaching the screw P, attach the wire clamp together

with it.

• After connecting the wire to the connector ACW2

wire using the wire clamp.

3.1.11 Removing the power trans

(See Fig.14)

• Prior to performing the following procedures, remove th e top
cover, tray door, DVD mechanism assembly, fan motor, rear
panel, video board and function board.
(1) From the top side of the ma in body, disconnect the wires

from the connectors ACW2
the main board.

(2) Remove the four screws Q attaching the power trans.

, ACW3, ACW4 an d ACW5 on

, ACW3,

, bundle the

Power trans

Q

CW4

P

CW3

CW5

P

P

Q

Fig.14

Wire clamp

ACW2

(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.
(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

front board.

(3) Take out the front board from the fro nt panel assembly.

3.2.2 Removing the power SW board

(See Fig.15)

• Prior to performing the following procedures, remove the top
cover, tray door, front panel assembly and front board.
(1) Remove the screw S attaching the power SW board.
(2) Take out the power SW board from the front panel

assembly.

on the

Front board Power SW boardUCW13

Wire

R S

Fig.15

1-12 (No.MB141)

SECTION 4

ADJUSTMENT

This service manual does not describe ADJUSTMENT.

(No.MB141)1-13

5.1 MAIN

5.1.1 POWER

SECTION 5

TROUBLESHOOTING

Check for VCC(5V)

FRONT PCB

at
;pin #17,46,72,90 of UIC1

YES

Check for power-sense(5V)at FRONT PCB
;pin #77 of UIC1

YES

When power on for FRONT PCB

Check for High Voltage(5V) at"M"com

74 of UIC1

;pin#

NO

NO

Check for Input voltage

POWER PCB

at
;AIC1(7805)

YES

Replace

Check normal Voltage
at

POWER PCB

AZD1 (5.1V, 1/2W)

YES

Check pattern from VCW7
to pin#77 of UIC1

NO

AIC1

NO

Check for circuit at Sub Trans

;PBD2, PT1, AFS3(Fuse)

Replace AZD1

NO

Check resistant from GND
to pin #77 of MICOM(UIC1)
if the short(0 ohm),to replace
Micom(UIC1)

Check for connector from DSP PCB to FRONT PCB
;VCW7

1-14 (No.MB141)

YES

Check low Voltage(0V)

at

EXPAND IC (M66010)

;pin#32 of UIC500

YES

Replace Micom(UIC1)

NO

If High Voltage (5V), check for Circuit protection
Check connector wire Ass'y of power

P/T - MAIN PCB(7P,ACW3)
MAIN PCB (8P,PW3)

5.1.2 OUTPUT

Check voltage at Main PCB
; VM, VL

YES

Check Audio channel at CW5
for input:5.1 channel Audio signal

YES

NO

Check Connector PW1
Check ABD2,4

NO

Check Voltage for CW7
; 12V

Check signal for FR/FL/C/W/RL/RR
at MAIN PCB

YES

Check voltage for CW7(SPK Relay)

;High(5V)

Check Q4,Q5

NO

NO

Check circuit for AMP channel
;Out ports of FIC6, IC7, RIC5
Reference to NEXT page
; "A" position

Check circuit for Speak Relay

(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

-12V

YES

Check Voltage
for Main AMP of Main PCB
VM, VL

YES

"A"

Check DC Voltage for Speaker port

NO

Check circuit for voltage(-12V)

NO

Check ABD2,4

NO

Check circuit for DC Voltage

1-16 (No.MB141)

YES

Check the parts is normal?
;ZD6,ZD5(3.9V)

;R33,R36(27K)
R34,R37 (150 O h m)

YES

Check normal condition for Q15(C945)

;temperature-sense S/W be operated in the Power Trans

is Turn on

YES

Check electric potention for PBD 1, ABD1, PD3 at DVD Power PCB

NO

NO

Replace P/T, Q15

Check circuit for
Diode behind position

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

3

4

DVD single or

Dual layer judgement

Is Tray closed?

Y

Pick up headinit ial position.

Disc present or not

Disc present

Y

CD or DVD judgement

DVD

N

CD

Tray close operation.

about 3sec.

N

Y

Is Tray closed?

Stop Close operation.

Wait Open Command from MPEG

N

Laser Off

Monitor Display=NO DISC

CD or CDRW

judgement

Single

DVD single

initial setting

Dual

DVD Dual

initial setting

To Each disc playback

(DVD Dual) (DVD single)

CD CDRW

CD

initial setting

CDRW

initial setting

1-18 (No.MB141)

5.2.2 Play operation

Play

5

Disc Motor forced accelleration

Repeat

seveal times

Change

Disc Type

Focus Seach

Is focus servo

on?

Track servo ON

CLV servo ON

6

7

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

OK

Does Pick Up
Move to inner

direction?

Y

Does Pick Up

Move to out

direction again?

Y

Does Laser Turn

On?

N

Is pulse of 2.5

Y

+-2.5V developed

at pin3,4 of MJ4?

Check

connection

between PCB

and MECHA

N

Is pulse of 2.5

+-2.5V developed

at pin13 of SIC1

Y

N

Check

peripheral

circuit of SIC1

and DRIC1

Check BUS

line between

SIC1 and MIC1

N

Is pin5 of MJ4 =

N

"L" appeared?

Check

connection

between PCB

Y

Check line between SIC1

and MJ4

and MECHA

N

Check voltage at

pin8 of RCN1 is

about 2.5V?

N

Check BUS line between RIC1 and

SIC1,SIC1 and MIC1

Y

Replace Pick Up Head

1-20 (No.MB141)

5.2.4 Disc Presence/Absense Judgment

4

Disc Presence Judgment

Turn On Laser

Does lens move

with UP/DOWN

full stroke in focus

direction?

Y

Check PI
(pin36 of RU1)
signal and FE

(pin42 of RIC1)signal

Normal

Disc is presence

N

Is focus search

voltage developed

at pin 11 of SIC1

N

Check

Y

peripheral
circuit of DRIC1

Check BUS
line between
SIC1 and MIC1

YNo signal

No Disc OK

N

Check connection between RIC1 and RCN1.
Check BUS line RIC1and SIC1.
Check RIC1

(No.MB141)1-21

5.2.5 Disc Motor Does Not Rotate

Disc Motor Does Not Rotate

5

Is Voltage of 0V

developed at

pin15 of SIC1

Check peripheral circuit of SIC1.
Check SIC1

5.2.6 Focus Servo does not Work

Focus Servo does not Work

Are FE(pin42 of RIC1)

and PI(pin36 of RIC1)

normal?

Y

Check peripheral circuit of DRIC1

N

6

N

Check peripheral circuit of SIC1 and
RIC1

Y

Check peripheral circuit of SIC1 and
RIC1

Check peripheral circuit of DRIC1

Check Connection between PCB and
MECHA

(CD-RW)

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