JVC KDG-120-R, KDG-123, KDG-125, KDG-124, KDG-126 Service manual

MA233200512

SERVICE MANUAL

CD RECEIVER

KD-G120,KD-G120R,KD-G123,

KD-G124,KD-G125,KD-G126,

KD-G161,KD-G162

KD-G120RKD-G120

KD-G123 KD-G124

KD-G125 KD-G126

KD-G126

KD-G161 KD-G162

KD-G161

Lead free solder used in the board (material : Sn-Ag-Cu, melting point : 219 Centigrade)

KD-G125

KD-G162

KD-G120,KD-G120R

J ------------- Northern America

KD-G123,KG-G124

UI ---------------------------- India

KD-G125,KD-G126

UT ------------------------- Taiwan
UH ---------------------- Thailand
UN --------------------- Indonesia
U -------------------- Other Areas

KD-G161,KD-G162

E ------------- Southern Europe
EX ------------ Northern Europe
EY ------------- Eastern Europe
EU ------------------------- Turkey

Area suffix

Area suffix

Area suffix

Area suffix

TABLE OF CONTENTS

1 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14

COPYRIGHT © 2005 Victor Company of Japan, Limited

No.MA233

2005/12

SPECIFICATION

KD-G120R/KD-G120

AUDIO AMPLIFIER SECTION

Power Output 17 W RMS × 4 Channels at 4 Ω and [< or =] 1% THD+N
Signal to Noise Ratio 80 dBA (reference: 1 W into 4 Ω)
Load Impedance 4 Ω (4 Ω to 8 Ω allowance)

Tone Control Range Bass ±10 dB at 100 Hz

Treble ±10 dB at 10 kHz

Frequency Response 40 Hz to 20 000 Hz

Line-Out Level/Impedance 2.0 V/20 kΩ load (full scale)
Output Impedance 1 kΩ
Subwoofer-Out Level/Impedance 2.0 V/20 kΩ load (full scale)

TUNER SECTION

Frequency Range FM 87.5 MHz to 107.9 MHz (with channel interval set to 100 kHz or 200 kHz)

AM 530 kHz to 1 710 kHz (with channel interval set to 10 kHz)

FM Tuner Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω)

50 dB Quieting Sensitivity 16.3 dBf (1.8 µV/75 Ω)

Alternate Channel Selectivity (400 kHz) 65 dB

Frequency Response 40 Hz to 15 000 Hz

Stereo Separation 35 dB

Capture Ratio 1.5 dB

AM Tuner Sensitivity 20 µV

Selectivity 35 dB

Type Compact disc player

Signal Detection System Non-contact optical pickup (semiconductor laser)

Number of channels 2 channels (stereo)

Frequency Response 5 Hz to 20 000 Hz

Dynamic Range 96 dB

Signal-to-Noise Ratio 98 dB

Wow and Flutter Less than measurable limit

Power Requirement Operating Voltage DC 14.4 V (11 V to 16 V allowance)

Grounding System Negative ground

Allowable Operating Temperature 0°C to +40°C (32°F to 104°F)
Dimensions (W × H × D) Installation Size (approx.) 182 mm × 52 mm × 150 mm (7-3/16" × 2-1/16" × 5-15/16")

Panel Size (approx.) 188 mm × 58 mm × 11 mm (7-7/16" × 2-5/16" × 7/16")

Mass (approx.) 1.2 kg (2.6 lbs) (excluding accessories)

87.5 MHz to 108.0 MHz (with channel interval set to 50 kHz)

531 kHz to 1 602 kHz (with channel interval set to 9 kHz)

CD PLAYER SECTION

GENERAL

Design and specifications are subject to change without notice.

1-2 (No.MA233)

KD-G124/KD-G123

AUDIO AMPLIFIER SECTION

Maximum Power Output Front 50 W per channel

Rear 50 W per channel

Continuous Power Output
(RMS)

Load Impedance 4 Ω (4 Ω to 8 Ω allowance)

Tone Control Range Bass ±10 dB at 100 Hz

Frequency Response 40 Hz to 20 000 Hz

Signal to Noise Ratio 70 dB

Line-Out Level/Impedance 2.0 V/20 kΩ load (full scale)
Output Impedance 1 kΩ
Subwoofer-Out Level/Impedance 2.0 V/20 kΩ load (full scale)

Frequency Range FM 87.5 MHz to 108.0 MHz

FM Tuner Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω)

AM Tuner Sensitivity 20 µV

Type Compact disc player

Signal Detection System Non-contact optical pickup (semiconductor laser)

Number of channels 2 channels (stereo)

Frequency Response 5 Hz to 20 000 Hz

Dynamic Range 96 dB

Signal-to-Noise Ratio 98 dB

Wow and Flutter Wow and Flutter: Less than measurable limit

Power Requirement Operating Voltage DC 14.4 V (11 V to 16 V allowance)

Grounding System Negative ground

Allowable Operating Temperature 0°C to +40°C
Dimensions (W × H × D) Installation Size (approx.) 182 mm × 52 mm × 150 mm

Mass (approx.) 1.2 kg (excluding accessories)

Front 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total har-

monic distortion.

Rear 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total har-

monic distortion.

Treble ±10 dB at 10 kHz

TUNER SECTION

AM 531 kHz to 1 602 kHz

50 dB Quieting Sensitivity 16.3 dBf (1.8 µV/75 Ω)

Alternate Channel Selectivity (400 kHz) 65 dB

Frequency Response 40 Hz to 15 000 Hz

Stereo Separation 35 dB

Capture Ratio 1.5 dB

Selectivity 35 dB

CD PLAYER SECTION

GENERAL

Panel Size (approx.) 188 mm × 58 mm × 11 mm

Design and specifications are subject to change without notice.

(No.MA233)1-3

KD-G126/KD-G125

AUDIO AMPLIFIER SECTION

Maximum Power Output Front 50 W per channel

Rear 50 W per channel

Continuous Power Output
(RMS)

Load Impedance 4 Ω (4 Ω to 8 Ω allowance)

Tone Control Range Bass ±10 dB at 100 Hz

Frequency Response 40 Hz to 20 000 Hz

Signal to Noise Ratio 70 dB

Line-Out Level/Impedance 2.0 V/20 kΩ load (full scale)
Output Impedance 1 kΩ
Subwoofer-Out Level/Impedance 2.0 V/20 kΩ load (full scale)

Frequency Range FM 87.5 MHz to 108.0 MHz

FM Tuner Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω)

AM Tuner Sensitivity 20 µV

Type Compact disc player

Signal Detection System Non-contact optical pickup (semiconductor laser)

Number of channels 2 channels (stereo)

Frequency Response 5 Hz to 20 000 Hz

Dynamic Range 96 dB

Signal-to-Noise Ratio 98 dB

Wow and Flutter Less than measurable limit

Power Requirement Operating Voltage DC 14.4 V (11 V to 16 V allowance)

Grounding System Negative ground

Allowable Operating Temperature 0°C to +40°C
Dimensions (W × H × D) Installation Size (approx.) 182 mm × 52 mm × 150 mm

Mass (approx.) 1.2 kg (excluding accessories)

Front 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total har-

monic distortion.

Rear 19 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total har-

monic distortion.

Treble ±10 dB at 10 kHz

TUNER SECTION

AM 531 kHz to 1 602 kHz

50 dB Quieting Sensitivity 16.3 dBf (1.8 µV/75 Ω)

Alternate Channel Selectivity (400 kHz) 65 dB

Frequency Response 40 Hz to 15 000 Hz

Stereo Separation 35 dB

Capture Ratio 1.5 dB

Selectivity 35 dB

CD PLAYER SECTION

GENERAL

Panel Size (approx.) 188 mm × 58 mm × 11 mm

Design and specifications are subject to change without notice.

1-4 (No.MA233)

KD-G162/KD-G161

AUDIO AMPLIFIER SECTION

Maximum Power Output Front 45 W per channel

Rear 45 W per channel

Continuous Power Output
(RMS)

Load Impedance 4 Ω (4 Ω to 8 Ω allowance)

Tone Control Range Bass ±10 dB at 100 Hz

Frequency Response 40 Hz to 20 000 Hz

Signal-to-Noise Ratio 70 dB

Line-Out Level/Impedance 2.0 V/20 kΩ load (full scale)
Output Impedance 1 kΩ

Frequency Range FM 87.5 MHz to 108.0 MHz

FM Tuner Usable Sensitivity 11.3 dBf (1.0 µV/75 Ω)

MW Tuner Sensitivity 20 µV

LW Tuner Sensitivity 50 µV

Type Compact disc player

Signal Detection System Non-contact optical pickup (semiconductor laser)

Number of Channels 2 channels (stereo)

Frequency Response 5 Hz to 20 000 Hz

Dynamic Range 96 dB

Signal-to-Noise Ratio 98 dB

Wow and Flutter Less than measurable limit

Power Requirement Operating Voltage DC 14.4 V (11 V to 16 V allowance)

Grounding System Negative ground

Allowable Operating Temperature 0°C to +40°C
Dimensions (W × H × D) Installation Size (approx.) 182 mm × 52 mm × 150 mm

Mass (approx.) 1.2 kg (excluding accessories)

Front 17 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total har-

monic distortion.

Rear 17 W per channel into 4 Ω, 40 Hz to 20 000 Hz at no more than 0.8% total har-

monic distortion.

Treble ±10 dB at 10 kHz

TUNER SECTION

AM (MW) 522 kHz to 1 620 kHz

(LW) 144 kHz to 279 kHz

50 dB Quieting Sensitivity 16.3 dBf (1.8 µV/75 Ω)

Alternate Channel Selectivity (400 kHz) 65 dB

Frequency Response 40 Hz to 15 000 Hz

Stereo Separation 30 dB

Capture Ratio 1.5 dB

Selectivity 35 dB

CD PLAYER SECTION

GENERAL

Panel Size (approx.) 188 mm × 58 mm × 11 mm

Design and specifications are subject to change without notice.

(No.MA233)1-5

1.1 Safety Precautions

SECTION 1

PRECAUTIONS

!

!

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.

Please use enough caution not to see the beam directly or touch it in case of an
adjustment or operation check.

1-6 (No.MA233)

1.2 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.

1.2.1 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.

(caption)
Anti-static wrist strap

1M

Conductive material
(conductive sheet) or iron plate

(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.

1.3 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.

1.4 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 before the flexible wire is disconnected from the connector on the CD pickup unit.
(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 after connecting the flexible wire.

Pickup

Wires

Push switch

Base board

Frame

Flexible wire

Connector

CD mechanism
assembly

Pickup

(No.MA233)1-7

1.5 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 CD,MD and DVD 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.

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.

Please use enough caution not to
see the beam directly or touch it
in case of an adjustment or operation
check.

REPRODUCTION AND POSITION OF LABELS

WARNING LABEL

CAUTION : Visible and Invisible

CLASS 1
LASER PRODUCT

laser radiation when open and
interlock failed or defeated.
AVOID DIRECT EXPOSURE TO
BEAM. (e)

ADVARSEL : Synlig og usynlig
laserstråling når maskinen er
åben eller interlocken fejeler.
Undgå direkte eksponering til
stråling. (d)

VARNING : Synlig och
osynling laserstrålning när
den öppnas och spärren är
urkopplad. Betrakta ej
strålen. (s)

VARO : Avattaessa ja suojalukitus
ohitettuna tai viallisena olet alttiina
näkyvälle ja näkymättömälle
lasersäteilylle. Vältä säteen
kohdistumista suoraan itseesi. (f)

1-8 (No.MA233)

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 CD mechanism

For the CD mechanism, please refer mechanism manual TN2007-1001 (No. MY003).

(No.MA233)1-9

SECTION 3

DISASSEMBLY

3.1 Main body section

3.1.1 Removing the front panel assembly
(See Fig.1)

(1) Push the detach button in the lower right part of the front

panel assembly and remove the front panel assembly.

3.1.2 Removing the bottom cover
(See Fig.2)

(1) Turn the main body up side down.
(2) Insert a screwdriver under the joints to release the two

joints a on the left side, two joints b on the right side and
joint c on the back side of the main body, then remove the
bottom cover from the main body.

Note:

When releasing the joints using a screwdriver, do not damage
the main board.

Joint a

Front panel assembly

Fig.1

Bottom cover

Detach button

Joint

b

3.1.3 Removing the front chassis assembly
(See Fig.3)

• Remove the front panel assembly and bottom cover.

(1) Remove the two screws A on the both sides of the main

body.

(2) Release the two joints d and two joints e on the both sides

of the main body, then remove the front chassis assembly
toward the front.

Joint a

Joint c

Fig.2

Joint d Joint e

A

Joint d

Front chassis assembly

Fig.3

Joint e

Joint b

1-10 (No.MA233)

3.1.4 Removing the side panel

(See Fig.4)

Reference:

Remove the front panel assembly as required.
(1) Remove the screw B and two screws C attaching the side

panel on the left side of the main body.

(2) Remove the side panel from the main body.

3.1.5 Removing the rear bracket

(See Fig.5)

• Remove the bottom cover.

(1) Remove the three screws D, three screws E and two

screws F attaching the rear bracket on the back side of the
main body.

(2) Remove the rear bracket.

3.1.6 Removing the main board

(See Figs.5 and 6)

• Remove the front panel assembly, bottom cover and side pan-

el.

Reference:

Remove the front chassis assembly as required.
(1) Remove the three screws D attaching the rear bracket on

the back side of the main body. (See Fig.5.)

(2) Remove the two screws G attaching the main board. (See

Fig.6.)

(3) Disconnect the connector CN501

the main body and take out the main board with the rear
bracket. (See Fig.6.)

Reference:

Remove the rear bracket from the main body as required. (See
"3.1.5 Removing the rear bracket".)

on the main board from

C

B

Side panel

Fig.4

Rear bracket

EF

F

C

E

DD

Fig.5

CN501

G

Main board

G

Rear bracket

Fig.6

(No.MA233)1-11

3.1.7 Removing the CD mechanism assembly
(See Fig. 7)

• Remove the front panel assembly, bottom cover, side panel,

rear bracket and main board.

Reference:

Remove the front chassis assembly as required.

(1) Remove the three screws H attaching the CD mechanism

assembly on the top chassis.

(2) Take out the CD mechanism assembly.

H

3.1.8 Removing the switch board
(See Figs.8 to 10)

• Remove the front panel assembly.

(1) Remove the four screws J on the back side of the front pan-

el assembly. (See Fig.8.)
(2) Release the joints f and remove the rear cover. (See Fig.9.)
(3) Release the joint g and take out the switch board from the

front panel assembly. (See Fig.10.)

CD mechanism assembly

J

J

Rear cover

Top chassis

H

Fig.7

J

Fig.8

Joints f

1-12 (No.MA233)

Joints f Joints f

Switch board

Joints f

Fig.9

Front panel assembly

Joint g

Fig.10

SECTION 4

ADJUSTMENT

4.1 Adjustment method

 Test instruments required for adjustment

(1) Digital oscilloscope (100MHz)
(2) Electric voltmeter
(3) Digital tester
(4) Tracking offset meter
(5) Test Disc JVC :CTS-1000
(6) Extension cable for check

EXTSH002-22P × 1

 Standard volume position

Balance and Bass &Treble volume : lndication"0"
Loudness : OFF

 How to connect the extension cable for adjusting

Caution:

Be sure to attach the heat sink and rear bracket onto the power amplifier IC and regulator IC respectively, before supply the power.
If voltage is applied without attaching these parts, the power amplifier IC and regulator IC will be destroyed by heat.

 Standard measuring conditions

Power supply voltage DC14.4V(10.5 to 16V)

Load impedance 20KΩ(2 Speakers connection)

Output Level Line out 2.0V (Vol. MAX)

 Dummy load

Exclusive dummy load should be used for AM,and FM. For FM
dummy load,there is a loss of 6dB between SSG output and
antenna input.The loss of 6dB need not be considered since
direct reading of figures are applied in this working standard.

CAUTION :

Be sure to attach the heat sink and rear bracket onto the
power amplifier and regulator respectively, before supply the
power.
If voltage is applied without attaching those parts, the power
amplifier IC and regulator IC will be destroyed by heat.

Heat sink

Extension cable

EXTSH002-22P

Rear bracket

(No.MA233)1-13

SECTION 5

TROUBLESHOOTING

5.1 Trouble shooting (For KD-G120, KD-G120R, KD-G123, KD-G124,KD-G125 and KD-G126)

5.1.1 Feed section

Is 4V present at both
sides of the feed motor?

NO

Is the voltage output at
pin 4 and pin 5 of IC541?

NO

Is the voltage input at pin
28 of IC541?

NO

Is the voltage output at pin
21 and pin 22 of IC561?

NO
Is the power supply
present at pin 4, pin 50,
pin 60 and pin 72 of IC561?

NO

Check the connections
of CD8V power supply.

5.1.2 Focus section

YES

Check the feed motor.

Check the connections

YES

between the feed motor
and IC541.

Is the power supply

YES YES

present at pin 3, pin 12
and pin 21 of IC541?

NO

Check the connections
of CD8V power supply.

Check the connections

YES

between IC541 and
IC561.

YES

Check IC561.

Check IC541.

When the lens is
moving:

4V

Does the S-search
waveform appear at
IC541 pins 8 and 9?

NO

Is the voltage input at pin
15 of IC541?

NO

Is the voltage output at
pin 28 of IC561?

NO

Is the power supply
present at pin 4, pin 50,
pin 60 and pin 72 of IC561?

NO

YES

Check the pickup and
its connections.

Is the power supply

YES

present at pin 3, pin 12
and pin 21 of IC541?

Check the connections
of CD8V power supply.

Check the connections

YES

between IC541 and
IC561.

YES

Check IC561.

YES

Check IC541.

NO

1-14 (No.MA233)

Check the connections
of CD8V power supply.

5.1.3 Spindle section

Is the disk rotated?

YES

Does the RF signal
appear at RF TP?

YES

Is the RF waveform
at TP RF distorted?

NO

Is the voltage output at
pin 6 and pin 7 of IC541?

NO

Is the voltage input at pin
17 of IC541?

NO

Is the voltage output at pin
24 and pin 25 of IC561?

NO

Is the power supply
present at pin 4, pin 50,
pin 60 and pin 72 of IC561?

NO

Check the connections
of CD8V power supply.

5.1.4 Tracking section

YES

Check the spindle motor
and its wiring.

Is the power supply

YES

present at pin 3, pin 12
and pin 21 of IC541?

Check the connections
of CD8V power supply.

Check the connections

YES

between IC541 and
IC561.

YES

Check IC561.

NO

NONO

Check the circuits in
the vicinity of IC501
or the pickup.

YES

Check IC541.

YES

Proceed to the Tracking
section

When the disc is rotated
at first:

Approx. 1.2V

Is the tracking error
signal output at TE TP?

NO

Check the circuits in
IC501 or the vicinity
of IC501.

NO

Replace IC501 or repair
the malfunction
connection point

YES

Check IC561.

YES

Check the pickup and
its connections.

(No.MA233)1-15

5.1.5 Signal processing section

Is the sound output from

YES

both channels (L, R)?

Normal

NO

No sound from either
channel.

NO

Compare the L-ch and
R-ch to locate the
defective point.

YES

Is 9V present at pin 26
of IC301?

Is 9V present at pin 10
of IC901?

Check IC901 and its
peripheral circuits.

NO

NO

Is the audio signal
(including sampling

YES YES

output components)
output to pins 1 and 7 of
IC151 during playback?

NO

Check IC151 and its
peripheral circuits.

Check the connections

YES

between pin 26 of IC301
and pin 10 of IC901.

Is the audio signal output
at pin 22 and pin 25 of
IC301 during playback?

NO

Check IC301 and its
peripheral circuits.

YES

Check the power
amplifier IC321.

1-16 (No.MA233)

5.2 Trouble shooting (For KD-G161 and KD-G162)

5.2.1 Feed section

Is 4V present at both

YES

sides of the feed motor?

NO

Is the voltage output at

YES

pin 4 and pin 5 of IC501?

NO

Is the voltage input at pin

YES YES

28 of IC501?

NO

Is the voltage output at

YES

pin 7 of IC521?

NO

Is the power supply
present at pin 16, pin 37,

YES

pin 49, pin 53, pin 56
and pin 72 of IC521?

NO

Check the feed motor.

Check the connections
between the feed motor
and IC501.

Is the power supply
present at pin 3, pin 12
and pin 21 of IC501?

NO

Check the connections
of CD8V power supply.

Check the connections
between IC501 and
IC521.

Check IC521.

Check IC501.

5.2.2 Focus section

Check the connections
of CD8V power supply.

When the lens is
moving:

4V

Does the S-search
waveform appear at
IC501 pins 8 and 9?

NO

Is the voltage input at pin
15 of IC501?

NO

Is the voltage output at
pin 13 of IC521?

NO

Is the power supply
present at pin 16, pin 37,
pin 49, pin 53, pin 56
and pin 72 of IC521?

NO

YES

Check the pickup and
its connections.

Is the power supply

YES

present at pin 3, pin 12
and pin 21 of IC501?

Check the connections
of CD8V power supply.

Check the connections

YES

between IC501 and
IC521.

YES

Check IC521.

YES

Check IC501.

NO

Check the connections
of CD8V power supply.

(No.MA233)1-17

5.2.3 Spindle section

Is the disk rotated?

YES

Does the RF signal appear
at pin 39 of IC521?

YES

Is the RF waveform at
pin 39 of IC521 distorted?

NO

Is the voltage output at
pin 6 and pin 7 of IC501?

NO

Is the voltage input at pin
17 of IC501?

NO

Is the voltage output at
pin 5 of IC521?

NO

Is the power supply
present at pin 16, pin 37,
pin 49, pin 53, pin 56
and pin 72 of IC521?

NO

Check the connections
of CD8V power supply.

5.2.4 Tracking section

YES

Check the spindle motor
and its wiring.

Is the power supply

YES

present at pin 3, pin 12
and pin 21 of IC501?

Check the connections
of CD8V power supply.

Check the connections

YES

between IC501 and
IC521.

YES

Check IC521.

NO

NONO

Check the circuits in
the vicinity of IC521
or the pickup.

YES

Check IC501.

YES

Proceed to the Tracking
section

When the disc is rotated
at first:

Approx. 1.2V

Is the tracking error
signal output at pin 26
of IC521?

NO

Check the pickup and
its connections.

Replace IC521 or repair

YES

the malfunction
connection point

1-18 (No.MA233)

5.2.5 Signal processing section

Is the sound output from

YES

both channels (L, R)?

Normal

NO

No sound from either
channel.

NO

Compare the L-ch and
R-ch to locate the
defective point.

YES

Is 9V present at pin 32
of IC171?

Is 9V present at pin 13
of IC901?

Check IC901 and its
peripheral circuits.

NO

NO

Is the audio signal
(including sampling

YES

output components)
output to pins 1 and 7 of
IC581 during playback?

Check IC581 and its
peripheral circuits.

Check the connections

YES

between pin 32 of IC171
and pin 13 of IC901.

NO

Is the audio signal output

YES

at pin 14,pin 15, pin 18
and pin 19 of IC171 during
playback?

Check IC171 and its
peripheral circuits.

Check the power
amplifier IC301.

NO

YES

(No.MA233)1-19

5.3 Maintenance of laser pickup

(1) Cleaning the pick up lens

Before you replace the pick up, please try to clean the lens
with a alcohol soaked cotton swab.

(2) Life of the laser diode

When the life of the laser diode has expired, the following
symptoms will appear.

• The level of RF output (EFM output: amplitude of eye
pattern) will be low.

5.4 Replacement of laser pickup

Turn of the power switch and, disconnect the
power cord.

Replace the pickup with a normal one. (Refer
to "Removing the pickup unit" on the previous page.)

Is RF output

1.3 0.4Vp-p?

NO

Replace it.

YES

OK

(3) Semi-fixed resistor on the APC PC board

The semi-fixed resistor on the APC printed circuit board
which is attached to the pickup is used to adjust the laser
power.Since this adjustment should be performed to match
the characteristics of the whole optical block, do not touch
the semi-fixed resistor.
If the laser power is lower than the specified value, the la­ser diode is almost worn out, and the laser pickup should
be replaced. If the semi-fixed resistor is adjusted while the
pickup is functioning normally, the laser pickup may be
damaged due to excessive current.

Plug the power cord in, and turn the power on.
At this time, check that the laser emits for about
seconds and the objective lens moves up and down.
Note: Do not observe the laser beam directly.

Play a disc.

Check the eye-pattern at

RF output or RF TP.

Finish.

1-20 (No.MA233)

5.5 16 PIN CORD DIAGRAM (For KD-G120 and KD-G120R)

8
7

6
5

4

3

2

1

BK

RD

NC

BL/WH

WH

GN

VI

GY

YL

NC

NC

NC

WH/BK

GN/BK

VI/BK

GY/BK

16 YL

8 BK

7 RD

3 GN

11 GN/BK

2 VI

10 VI/BK

4 WH

16

15

14
13

12

11

10

9

MEMORY

GND

ACC

RL+

RL-

RR+

RR-

FL+

BK

RD

BL

Black

Red

Blue

WH White

GN

VI

GY

YL

Green

Violet

Gray

Yellow

GND

12 WH/BK

1 GY

9 GY/BK

5 BL/WH

Rear Right

RR

FL

Front Right

Front Left

Rear Left

FR

RL

FL-

FR+

FR-

REMOTE

REMOTE OUT

REMOTE

ACC

MEMORY

GND

Remote out

ACC Line

Memory Backup Battery+

Ground

(No.MA233)1-21