LG CD-363 SERVICE MANUAL

- 1-1 -

❍

SECTION 1. SUMMARY

• SERVICING PRECAUTIONS

.........................................................................................................

1-2

• ESD PRECAUTIONS

......................................................................................................................

1-4

• SPECIFICATIONS

..........................................................................................................................

1-5

• IDENTIFICATION OF CONTROLS

................................................................................................

1-6

❍

SECTION 2. ELECTRICAL SECTION

• ADJUSTMENT

................................................................................................................................

2-1

• TROUBLESHOOTING GUDIE

.......................................................................................................

2-2

• INTERNAL BLOCK DIAGRAM OF IC’s

........................................................................................

2-11

• IC VOLTAGE SHEET

..................................................................................................................

2-22

• BLOCK DIAGRAM

........................................................................................................................

2-24

• MAIN & TUNER SCHEMATIC DIAGRAMS

..................................................................................

2-26

• µ-COM SCHEMATIC DIAGRAMS

...............................................................................................

2-28

• CD SCHEMATIC DIAGRAMS

......................................................................................................

2-30

• PRINTED CIRCUIT DIARGAMS

..................................................................................................

2-32

❍

SECTION 3. EXPLODED VIEWS

.......................................................................................

3-1

❍

SECTION 4. REPLACEMENT PARTS LIST

...................................................................

4-1

[CONTENTS]

❏ SERVICING PRECAUTIONS

[NOTES REGARDING HANDLING OF THE PICK-UP]

➊ Notes for transport and storage

1) The pick-up should always be left in its conductive bag until immediately prior to use.

2) The pick-up should never be subjected to external pressure or impact.

➋ Repair notes

1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials.

2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure and
impact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/or
damage to the printed-circuit board.

3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason
the adjustment point and installation screws should absolutely never be touched.

4) Laser beams may damage the eyes!
Absolutely never permit laser beams to enter the eyes!
Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged.

5) Cleaning the lens surface
If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used
for camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a
cotton swab should be used, taking care not to distort this.

6) Never attempt to disassemble the pick-up.
Spring by excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab. (Do
not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much of
this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.

- 1-2 -

Storage in conductive bag

Drop impact

NEVER look directly at the laser beam, and don’t let
contact fingers or other exposed skin.

Magnet

How to hold the pick-up

Pressure

Pressure

Cotton swab

Conductive Sheet

SECTION 1. SUMMARY

[NOTES REGARDING COMPACT DISC PLAYER REPAIRS]

➊ Preparations

1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These
components are sensitive to, and easily affected by, static electricity. If such static electricity is high
voltage, components can be damaged, and for that reason components should be handled with care.

2) The pick-up is composed of many optical components and other high-precision components. Care must
be taken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong
magnetism is present, or where there is excessive dust.

➋ Notes for repair

1) Before replacing a component part, first disconnect the power supply lead wire from the unit

2) All equipment, measuring instruments and tools must be grounded.

3) The workbench should be covered with a conductive sheet and grounded.
When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This is
because there is the possibility of damage by static electricity.)

4) To prevent AC leakage, the metal part of the soldering iron should be grounded.

5) Workers should be grounded by an armband (1MΩ)

6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent
static electricity changes in the clothing to escape from the armband.

7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.

- 1-3 -

Armband

Conductive
Sheet

Resistor
(1 Mohm)

Resistor
(1 Mohm)

❏ ESD PRECAUTIONS

[Electrostatically Sensitive Devices (ESD)]

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components
commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated
circuits and some field-effect transistors and semiconductor chip components. The following techniques should
be used to help reduce the incidence of component damage caused by static electricity.

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off
any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device, which should be removed for potential shock reasons
prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive

surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ESD devices.

4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static" can

generate electrical charges sufficient to damage ESD devices.

5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESD

devices.

6. Do not remove a replacement ESD device from its protective package until immediately before you are ready

to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by
conductive foam, aluminum foil or comparable conductive materials).

7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the

protective material to the chassis or circuit assembly into which the device will by installed.

CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER

SAFETY PRECAUTIONS.

8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motion

such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can
generate static electricity sufficient to damage an ESD device).

[CAUTION. GRAPHIC SYMBOLS]

- 1-4 -

THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL
TRIANGLE, IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE
OF UNINSULATED “DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT
MAGNITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.

THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO
ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY
INFORMATION IN SERVICE LITERATURE.

- 1-5 -

❏ SPECIFICATIONS

* Designs and specifications are subject to change without notice for improvement.

- 1-6 -

❏ IDENTIFICATION OF CONTROLS

UP PANEL/FRONT PANEL

• UP PANEL (CD-363A/AX and CD-364A Model)

• FRONT PANEL (CD-363A/AX Model)

• FRONT PANEL (CD-364A Model)

10

8

9
8

5
7

9
8

5
7

6

6

1
2

3

3

3

4

4

5

5

CD DOOR

FUNCTION SWITCH
[CD/ FM/ AM/ TAPE (OFF)]

VOLUME CONTROL DIAL

DISPLAY WINDOW INDICATOR

LEFT/ RIGHT SPEAKER

TAPE FUNCTION BUTTONS

• RECORD (REC ) BUTTON

• TAPE PLAY (PLAY ) BUTTON

• REWIND (REW ) BUTTON

• FAST FORWARD (FF ) BUTTON

• TAPE STOP (ST )/
TAPE DOOR OPEN (EJ )BUTTON

• TAPE PAUSE (PAUSE ) BUTTON

TAPE DOOR

TUNING DIAL

CD FUNCTION BUTTONS

• CD REPEAT BUTTON

• CD PLAY/PAUSE ( ) BUTTON

• CD SKIP/SEARCH ( , )BUTTON

• CD STOP ( ) BUTTON

• CD DOOR OPEN ( OPEN) BUTTON

FREQUENCY INDICATOR

10

9

8

7

6

5

4

3

2

1

- 1-7 -

REAR PANEL/DISPLAY WINDOW

RPT 1 ALL

RPT 1 ALL

• REAR PANEL (CD-363A/AX and CD-364A Model)

• DISPLAY WINDOW (CD-363A/AX Model)

• DISPLAY WINDOW (CD-364A Model)

1

2

3

10

10

4

7

6 5

8
9

FM ANTENNA

RIF/FM MODE SWITCH (ST./MONO)

AC POWER INPUT SOCKET

VOLTAGE SELECTOR (OPTIONAL)

HEADPHONE SOCKET ( ): 3.5mm

BATTERY COMPARTMENT

CD REPEAT PLAY INDICATOR

CD PLAY INDICATOR

CD PAUSE INDICATOR

CD TRACK NUMBER INDICATOR

10

9

8

7

6

5

4

3

2

1

7
8

9

- 2-1 -

❏ ADJUSTMENT

1. AM(MW) IF Adjustment

2. AM RF ADJUSTMENT

3. FM RF ADJUSTMENT

4. TAPE DECK ADJUSTMENT

SECTION 2. ELECTRICAL SECTION

STEP ITEM SG OUTPUT Adjust for Adjustment

1IF450KHz Maximum L12

STEP ITEM SG OUTPUT Adjust for Adjustment

1 515KHz Maximum L8

2 COVERAGE 1,650KHz Maximum VC1-3

3 Repeat steps 1 and 2 for several times

4 600KHz Maximum L4

5 TRACKING 1,400KHz Maximum VC1-4

6 Repeat steps 4 and 5 for several times

STEP ITEM SG OUTPUT Adjust for Adjustment

1 87.35MHz(AX:64MHz) Maximum L11

2 108.25MHz(AX:109MHz) Maximum VC1-2

3 Repeat steps 1 and 2 for several times

4 90MHz(AX:68MHz) Maximum L9

5 106MHz Maximum VC1-1

6 Repeat steps 4 and 5 for several times

COVERAGE

TRACKING

Deck Mode Test Tape Test Point Adjust for Adjustment

Play back MTT-114 L/R Output R/L Maximum Azimuth adjusting Screw

SPEED STT-111N 3000±30 Speed adjusting Screw

- 2-2 -

CD PART

YES

YES

NO

NO

YES

NO

YES

NO

OK

YES

END

IS THE FUNCTION SELECTOR IN

THE CD POSITION?

IS POWER TURNED ON?

DOES INITIAL READING OCCUR?

CAN DISC BE PLAYED?

IS AUDIO OUTPUT SUPPLIED?

CHECK AUDIO CIRCUITRY.

CHECK TRACKING SERVO

CIRCUITRY.

CHECK DISC.

CHECK FOCUSING CIRCUITRY.

CHECK LASER CIRCUITRY.

CHECK POWER SUPPLY

CIRCUITRY.

❏ TROUBLESHOOTING GUDIE

1. CD PART

• CD CIRCUIT

- 2-3 -

0V

3V

3V

RESET 0V

About 0.125 µsec

3V

IS THE FUNCTION SELECTOR

IN THE CD POSITION?

DO DISPLAY LCD THEN

LIGHT?

CHECK VOLTAGE IN THE

POWER SUPPLY CIRCUITRY.

IS µ-COM RESET CIRCUIT
NOMAIL MICOM

VDD

· POWER SUPPLY CIRCUITRY
DEFECTIVE

· CHECK CN101 AND CN105

CD FUNCTION

IS µ-COM 201PIN11 AND 12

(OSC) INPUT?

IS IC201 PIN30, 31, 32, 33 TO

40 OUTPUT WAVEFORM

NORMAL?

· DISPLAY DEFECTIVE.

· PATTERN DEFECTIVE.

· XT201 DEFECTIVE.

· RESET CIRCUIT DEFECTIVE.

· SURROUNDING CIRCUIT
DEFECTIVE.

(1) IF DISPLAY LCD LIGHTING IS ABNORMAL

(WITHOUT DISC)

NO

YES

YES

YES

YES

NO

NO

NO

NO

- 2-4 -

3~4V

0V

DOSE DISC MOTOR

ROTATE?

IS HF WAVEFORM

OUTPUT? IC101

PIN2

IS TRACKING SERVO
OPERATING? IS THE
LOWER IC101 PIN2
WAVEFORM FLAT?

IS ROTATION NORMAL? IS
THERE ANY IRREGULARITY
IN FREQUENCY?

IS HF SIGNAL NORMAL WITHOUT
DROPOUT?

IS IC201 PIN49 OUTPUT

WAVEFORM NORMAL?

DOSE LASER LIGHT?

IS SIGNAL OUTPUT

AT IC101 PIN29

IS SIGNAL OUTPUT AT TRACKING

OUTPUT IC103 PIN26 ,27?

DOSE IC101 PIN20 (LOCK) AS

FIGURE?

IS TER SIGNAL

OUTPUT AT

IC101 PIN34?

· PATTERN
DEFECTIVE.

· IC 103
DEFECTIVE.

· IC 101
DEFECTIVE.

· DISC INITIAL READING
DAMAGED DEFECTIVE.

· PICK UP DEFECTIVE.

· PICK UP
DEFECTIVE

· CONNECTOR
DEFECTIVE.

· IC 101
DEFECTIVE.

· CONNECTOR
DEFECTIVE.

· PICK UP
DEFECTIVE

· LIMIT SW CONTACT DEFECTIVE.

· CONNECTOR DEPECTIVE.

· PATTERN SHORT.

DOOR OPEN

DOOR CLOSE

LOW

NO

NO

NO

NO

NO NO NO

NO

NO

NO

NO

(2) IF INITIAL READING IS NOT CARRIED OUT(WITH DISC)

YES

YES

YES

YES

YES

YES

YES

YES

- 2-5 -

WHEN LASER DOES NOT LIGHT

DOES LENSES MOVE UP AND DOWN?

HAS PICK-UP RETURNED TO
THE INNERMOST POSITION?

DOES PICK-UP STOP AFTER

HAVING MOVED TO THE
INNERMOST POSITION?

DOSE GENERATE ABOUT 2.5V AT

IC101 PIN18 (LD)?

FLOW LASER CURRENT? BOTH

VOLTAGE OF R108 IS ABOUT 0.7V?

HAS LASER POWER SOURCE RETURNED

TO THE Q101

(Q101 COLLECTOR VOLTAGE ABOUT 1.8V)

ARE DATA TRANSTERRED

FROM IC 201?

IS BELOW SIGNAL OUTPUT

AT IC103 PIN17, 18 ?

· IC 101, 103 DEFECTIVE.

· SLIDE MOTOR DEFECTIVE.

· CONNECTOR DEFECTIVE.

· IC103 DEFECTIVE.

· CONNECTOR DEFECTIVE.

· IC102 DEFECTIVE.

R526 » 0.7V

R526 « 0.7V

· IC101 DEFECTIVE.

· SURROUNDING CIRCUITRY DEFECTIVE.

· Q101 DEFECTIVE, CONNECTOR
DEFECTIVE.

· LASER DEFECTIVE.

· LASER DEFECTIVE.

·

CONNECTOR DEFECTIVE, SHORT ETC.

· CONNECTOR DEFECTIVE.

· IC201 DEFECTIVE.

A

NO NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES