LG LPCBM-340, LPCBM-345, LPCLM-340, LPCLM-345 Service manual

- 1-1 -

[CONTENTS]

❍ SECTION 1. GENERAL

• SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

❍ SECTION 2. ELECTRICAL

• ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

• TROUBLESHOOTING GUDIE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

• IC VOLTAGE SHEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

• BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21

• SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

• PRINTED CIRCUIT DIARGAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31

• WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43

❍ SECTION 3. EXPLODED VIEWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

❍ SECTION 4. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

- 1-2 -

SECTION 1. GENERAL

❏ SPECIFICATIONS

MODEL LPC-LM340A/X, LPC-BM340A/X

SECTION LPC-LM345A/X, LPC-BM345A/X

Power supply Refer to the back panel of the unit.
Power consumption 13W
Mass 3.24kg
External dimensions (W x H x D) 360 x 170 x 260mm
Output Power 2.5W x 2
Speakers 8Ω x 2
Battery Operation

DC 12V, eight “C”(R14) and four “AA”(R6) batteries (not supplied)
Fequency response 100 ~18000Hz
Signal-to-noise ratio 59dB
T.H.D 0.7%
Tuning Range 65~74MHz, 87.5~108MHz or 87.5 ~108MHz
Intermediate Frequency 10.7MHz
Antenna Telescopic antenna
Tuning Range 522~1611kHz or 530 ~1610kHz
Intermediate Frequency 450kHz
Antenna Ferrite bar antenna
Recording System 4 Tracks 2 channel stereo
Frequency Response 125 ~8000Hz
Signal to Noise Ratio 40/45dB (REC/PLAY)

[General][CD][TAPE]

[TUNER]

[AM] (MW)

[FM]

* Designs and specifications are subject to change without notice.

Remote Control Operation Range

Point the remote control at the remote sensor and press the buttons.

Distance: About 23 ft (7 m)from the front of the remote sensor.
Angle: About 30 °in each direction of the front of the remote sensor.

- 2-1 -

SECTION 2. ELECTRICAL

❏ ADJUSTMENTS

1. TAPE DECK ADJUSTMENT

DECK MODE TEST TAPE TEST POINT ADJUSTMENT

ADJUST FOR DECK ADJUST

PLAY BACK MTT-114

SPEAKER Output Azimuth adjusting screw

STOP

FWD: LEFT

L/R Maximum

RVS

FWD: RIGHT
RVS: LEFT

2. RECORD BIAS ADJUSTMENT

DECK MODE TEST TAPE TEST POINT ADJUSTMENT DECK ADJUST FOR

REC MODE MTT-5511 C241 L201

AUTO-RVS 85kHz±5kHz
AUTO-STOP 60kHz±5kHz

- 2-2 -

❏ TROUBLESHOOTING GUIDE

1. CD

- 2-3 -

• OPEN COLOSE NG

CONNECTOR LOCKING CHECK

DEFECTIVE MAIN

POWER SUPPLY

CHECK THE(SW502)

DEFECTIVE IC503

DEFECTIVE MICOM

MECHANISM

CHECK LOING CHECK (CN605, CN302)

CHECK VOLTAGE CHANGE LO+, LO- OF IC503

CHECK POWER SUPPLY CIRCUIT (CN603, CN302)

PN508 PIN8 = 6.2V, PIN7 = 5V, PN507 PIN1=5V

YES

YES

YES

NO

NO

NO

NO

- 2-4 -

• “READING” DISPLAY CHECK (=ONLY “CD” DISPLAY)

- 2-5 -

• READING OK CHECK (= “ NO DISC ” DISPLAY)

CONNECTOR LOCKING

CHECK(PN501 ,PN503)

DOES SLED MOVE?

DOSE LENSE MOVE?

(UP&DOWN)

DOSE LASER LIGHT?

DOES SPINDLE ROTATE?

IS READING OK?

CHECK PN501 PIN 14,15

(TA+,TA-)

CHECK PN503 PIN5.6

(SP+,SP-)

CHECK PN501 PIN 10(LD)

CHECK PN501 PIN 15, 16

(FA-,FA+)

CHECK PN503 PIN3, 4

(SL+,SL-)

DEFECTIVE PICKUP OR

IC503 OR IC501 OR IC502

DEFECTIVE PICKUP OR

IC503 OR IC501

DEFECTIVE PICKUP OR

IC502

DEFECTIVE PICKUP OR

IC503

DEFECTIVE PICKUP OR

IC503 OR IC501 OR IC502

A

B

C

D

E

NO

NO

NO

NO

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

- 2-6 -

• READING OK CHECK #A(=“NO DISC” DISPLAY)

DOSE SL+ WAVEFORM

APPEAR AT(IC503 PIN 14 AND

PN503 PIN3)WAVEFORM #2

SLED MOTOR WAVE

DOSE SLIN WAVEFORM

APPEAR AT (IC503 PIN5)

WAVEFORM #2 SLED

DRIVE WAVE

CHECK PN503 CONNECTOR LINE

DEFECTIVE IC501

DEFECTIVE IC503

DEFECTIVE PN503

CONNECTOR

DEFECTIVE PICUP

SLED MOTOR

A

YES

NO

NO

NO

NO

NO

- 2-7 -

• READING OK CHECK #B(=“NO DISC” DISPLAY)

DOSE FA+ WAVEFORM

APPEAR AT(IC503 PIN 1 5 AND

PN50 1 PIN 16)WAVEFORM #3

FOCUS COIL DRIVE WAVE

DOSE FAIN WAVEFORM

APPEAR AT (IC503 PIN26)

WAVEFORM #3 FOCUS

DRIVE WAVE

CHECK PN50 1 CONNECTOR LINE

DEFECTIVE IC50 1

DEFECTIVE IC503

DEFECTIVE PN501

CONNECTOR

DEFECTIVE PICUP

FOCUS ACTUATOR

B

YES

NO

NO

NO

NO

NO

- 2-8 -

• READING OK CHECK #C(=“NO DISC” DISPLAY)

IC ?V APPLIED TO PIN 10 OF PN501

LASER SUPPLY VOLTAGE CHECK

IS 3.3V APPLIED TO

PIN3 OF IC502

RF IC SUPPLY VOLTAGE

CHECK

CHECK PN501 CONNECTOR LINE

DEFECTIVE IC501

IS 2.0V PIC2 OF IC502

LASER CONTROL

VOLTAGE CHECK

DEFECTIVE IC501

DEFECTIVE IC503

DEFECTIVE PICUP

FOCUS ACTUATOR

DEFECTIVE PN501

CONNECTOR

C

YES

YES

NO

NO

NO

NO

NO

NO

- 2-9 -

• READING OK CHECK #D(=“NO DISC” DISPLAY)

DEFECTIVE IC501

DEFECTIVE IC503

DEFECTIVE PN503

CONNECTOR

DEFECTIVE PICUP
SPINDLE MOTOOR

CHECK PN503 CONNECTOR LINE

D

NO

NO

NO

NO

DOSE SP+ WAVEFORM

APPEAR AT(IC503 PIN 12 AND

PN503 PIN6)WAVEFORM #4

SPINDLE MOTOR DRIVE WAVE

DOSE SPIN WAVEFORM

APPEAR AT (IC503 PIN6)

WAVEFORM #4

SPINDLE DRIVE WAVE

YES

YES