LG CM2520 Schematic

MODEL: CM2520 (CM2520, CMS2520)SERVICE MANUAL

Internal Use Only

Website http://biz.lgservice.com

Micro Hi-Fi System

SERVICE MANUAL

P/NO : AFN75734072 APRIL, 2012

MODEL:

CAUTION

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

CM2520

(CM2520, CMS2520)

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

SERVICE INFORMATION FOR EEPROM .......................................................................................... 1-6

PROGRAM UPDATE GUIDE ................................................................................................................... 1-7

SPECIFICATIONS ....................................................................................................................................... 1-8

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 MΩ)

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 MΩ)

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

SERVICE INFORMATION FOR EEPROM

POWER ON

FLD Display "NO DISC" status

Set Front ‘STOP’ Key +

Remote control ‘FWD SKIP’ Key

push same timing during 5s

DETECT NEW EEPROM

FLD ‘OPT-XXXX’

Press SET Front "Play" Key Move to

appropriate position and make changes

with Set Front ‘FWD SKIP’ Key

Press Set Front ‘STOP’ Key +

Remote control ‘FWD SKIP’ Key

FLD Display ‘E2P CLR’

NAME

OPT OPT OPT OPT OPT

HEX

00000 (FM) 00001 (FM-NO IPOD) 01000 (FM_RDS) 10100 (FM_AM) D1000 (FM_DAB)

Press ‘POWER’ key

Completed

1-6

PROGRAM UPDATE GUIDE

HOW TO UPDATE MCS PROGRAM

(1) Change the file name to download as “(MODEL NAME)__(function)_(Version).mcs”. ex) CM2520_XXXX_XX.mcs (2) Copy the file to the root folder of USB storage. (3) Put the USB into the set. Change set function to USB function. Then the upgrade process will be started with the upgrade intormation. FLD Display "UPGRADE". (4) If the upgrade process is complete, the set will be rebooted with “SUCCESS” message and set auto power off. (5) Pull out the USB Storage. Press the power key.

1-7

SPECIFICATIONS

• GENERAL

Power supply 100 - 240 V, 50 / 60 Hz or 200 - 240 V, 50 / 60Hz Power consumption 35 W Net Weight 2.3 kg External dimensions (W x H x D) 230 x 125 x 243 mm Operating conditions Temperature 5 °C to 35 °C (41 °F to 95 °F) Operating humidity 5 % to 85 %

• TUNER

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

Ampliﬁ er Output Power 30 W + 30 W

• CD

Frequency Response 40 Hz to 20 kHz Signal-to-noise ratio 70 dB Dynamic range 55 dB

• USB

USB Version USB 2.0 or USB 1.1 Bus Power Supply DC 5 V 500 mA iPod/iPhone DC 5 V 1 A

• SPEAKERS

Type 2 Way 2 Speaker Impedance 6 Ω Rated Input Power 30 W Max. Input Power 60 W Net Dimensions (WxHxD) 150 x 251 x 158 mm Net Weight(1EA) 1.56 kg

• Design and speciﬁ cations are subject to change without notice.

1-8

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

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

1. CABINET AND MAIN FRAME SECTION (CM2520) ................................................................................ 2-3

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

3. SPEAKER SECTION (CMS2520) ............................................................................................................. 2-8

2-1

MEMO

2-2

EXPLODED VIEWS

1. CABINET AND MAIN FRAME SECTION (CM2520)

258

259

A42

257

260

252

USB

A48

261

264

452

263

256

262

255

451

IPOD

254

A43

269

451

FRONT

A49

454

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.

A26

CABLE10

CABLE12

453

452

251

453

451

CABLE11

270

279

268

453

A46

453

SMPS

A47

MAIN

300

253

265

450

267

450

MEMOMEMO

2. PACKING ACCESSORY SECTION

801 Instruction Ass'y

808 Battery

900 Remote Control

803T Packing

804 Bag

803B Packing

802 Box

3. SPEAKER SECTION (CMS2520)

A60L

A60R

+ 34 hidden pages