LG CM2760 Schematic

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL.

Internal Use Only

JANUARY, 2016

MODEL: CM2760 (CM2760, CMS2760F)

MODEL: CM2760

(CM2760, CMS2760F)

Micro Hi-Fi Audio

P/NO : AFN77360055

CONTENTS

SECTION 1 ........ GENERAL

SECTION 2 ........ CABINET & MAIN CHASSIS

SECTION 3 ........ ELECTRICAL

SECTION 4 ........ REPLACEMENT PARTS LIST

1-1

SECTION 1

SUMMARY

CONTENTS

SERVICING PRECAUTIONS ............................................................................................................................ 1-3

ESD PRECAUTIONS ......................................................................................................................................... 1-5

HIDDEN KEY MODE ......................................................................................................................................... 1-6

SOFTWARE UPDATE GUIDE

SPECIFICATIONS ............................................................................................................................................. 1-7

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

1-2

SERVICING PRECAUTIONS

NOTES REGARDING HANDLING OF THE PICK-UP

1. 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.

Storage in conductive bag

Drop impact

2. 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.

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

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 lens.

Pressure

Magnet

How to hold the pick-up

Cotton swab

Conductive Sheet

6) Never attempt to disassemble the pick-up. Spring has 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.

1-3

Pressure

NOTES REGARDING COMPACT DISC PLAYER REPAIRS

1. 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 or humidity is high, where strong magnetism is present, or where there is excessive dust.

2. 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 (1 M)

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.

Armband

Resistor (1 M)

Conductive Sheet

1-4

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

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

HIDDEN KEY MODE

HIDDEN

MODE

Version Check POWER ON STATUS

EEPROM INITIAL POWER ON STATUS

EEPROM EDIT POWER ON STATUS

APD Test Display POWER ON STATUS

B2B, Dealer

HIDDEN MODE

Clip On/Off POWER ON STATUS

Disc Lock On/Off POWER ON STATUS

Power Disc Lock On/Off POWER ON STATUS

Demo ALL Key Lock

BT Auto Power On/Off POWER ON STATUS

Sound BYPASS POWER ON STATUS

AVAILABLE STATUS ENTRANCE KEY EXIT KEY DISPLAY

POWER ON STATUS

Demo Function

Only Active

Front Play

+ RMC ‘Play’

for 5s

Front Play

+ RMC ‘|<<’

for 5s

Front Play

+ RMC ‘>>|’

for 5s

Front Play

+ RMC ‘DELETE’

for 5s

Front Play

+ RMC ‘Mute’

for 5s

Front Play

+ RMC ‘Stop’

for 5s

Front Play + RMC

‘SOUND EFFECT’

for 5s

Front Play + RMC ‘INFO’

for 5s

Front/RMC ‘Power’

for 5s

Front Play + RMC

‘PROGRAM’ for 5s

P1501290

RMC ‘PLAY’ for 1.5s

auto exit “E2P CLR”

Front Play + RMC ‘>>|’

Front Play + RMC ‘DE-

LETE’

auto exit

Front Play + RMC ‘Stop’

for 5s

Front Play + RMC

‘SOUND EFFECT’ for 5s

Front Play + RMC ‘INFO’

for 5s

Power normal Key SET

Power off

SOUND EFFECT key display ‘BYPASS’ 3s

‘LOCKED’/ ‘UNLOCKED’

OP0 FF

Q1501290

EQCSFFFF

OPT0-9F

( For Example )

APD MM:SS

(AUX modeH:MM:SS)

CLIP OFF 00 130 00

CLIP ON

‘KEY LOCK’/ ‘UNLOCKED’

OFF-AUTO POWER

GOOD BY Scroll

SOFTWARE UPDATE GUIDE

1) Prepare USB device without any ﬁ les.

2) Copy software (“CM2760_FW_2015xxxxx.bin”) into this USB device.

3) Power on the unit, switch to USB function.

4) Plug in USB device which contains software, no need other operations.

5) VFD display “SEARCH”  “MCS UP”  “FINISH”, then unit auto power off.

1-6

SPECIFICATIONS

• GENERAL

Power requirements Refer to the main label. Power consumption Refer to the main label. Networked standby : 0.5 W (If all network ports are activated.) Dimensions (W x H x D) Approx. 170 mm x 230 mm x 276 mm Net Weight Approx. 2.2 kg Operating temperature 5 °C to 35 °C Operating humidity 5 % to 90 %

• INPUTS

Portable in (PORT. IN) 0.45 Vrms (3.5 mm stereo jack) x 1

• TUNER

FM Tuning Range 87.5 to 108.0 MHz or 87.50 to 108.00 MHz

• AMPLIFIER (RMS OUTPUT POWER)

Total 160 W Front 80 W (4 Ω at 1 kHz, 10 % THD)

• SYSTEM

Frequency response 80 to 20,000 Hz Signal-to-noise ratio 80 dB Dynamic range 75 dB Bus Power Supply (USB) 5 V 500 mA

FRONT SPEAKERS

•

Type 3 Way 3 Speaker Impedance 4 Ω Rated Input Power 80 W Max. Input Power 160 W Dimensions (W x H x D) Approx. 127 mm x 295 mm x 240 mm Net Weight Approx. 3.36 kg

• Design and specifications are subject to change without notice.

1-7

1-8

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

EXPLODED VIEWS ........................................................................................................................................... 2-3

1. CABINET AND MAIN FRAME SECTION ................................................................................................. 2-3

2. PACKING ACCESSORY SECTION ......................................................................................................... 2-7

3. SPEAKER SECTION ................................................................................................................................ 2-8

2-1

2-2

MAIN

VFD

USB

PORTABLE

251

A52

A49

A48

A43

513

A46

266

516

513

265

515

514

513

A42

260

A00

261

263

A26

264

265

513

270

513

514

271

513

514

825

262

517

261

262

517

CABLE3

CABLE5

CABLE4

CABLE1

CABLE2

CABLE6

CABLE8

CABLE7

515

300

EXPLODED VIEWS

1. CABINET AND MAIN FRAME SECTION

NOTES) THE EXCLAMATION POINT WITHIN AN

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

2. PACKING ACCESSORY SECTION

801 Owner’s manual

808 Batteries

803T

804 Bag

Packing

900 Remote control

803B

Packing

802 Box

3. SPEAKER SECTION

A60L

A60R

+ 35 hidden pages