LG OM7560 Schematic

SERVICE MANUAL

CAUTION

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

Internal Use Only

Mini Hi-Fi AUDIO

APRIL, 2016P/NO : AFN77483239

MODEL: OM7560

CONTENTS

SECTION 1 ........ GENERAL

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

SECTION 3 ........ ELECTRICAL

SECTION 4 ........ MECHANISM (DM19AC)

SECTION 5 ........ REPLACEMENT PARTS LIST

1-1

SECTION 1

SUMMARY

CONTENTS

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

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

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

SERVICE INFORMATION FOR EEPROM ........................................................................................................ 1-7

PROGRAM DOWNLOAD GUIDE ...................................................................................................................... 1-8

SPECIFICATIONS ........................................................................................................................................... 1-11

1-2

1-3

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.

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.

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.

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.

Storage in conductive bag

Drop impact

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

Magnet

How to hold the pick-up

Conductive Sheet

Cotton swab

Pressure

SERVICING PRECAUTIONS

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.

Resistor (1 M)

Conductive Sheet

Resistor (1 M)

Armband

1-4

1-5

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.

ESD PRECAUTIONS

1-6

HIDDEN KEY MODE

Push both Front key and RCU key to activate it for 5 seconds.

1. Disc Lock On/Off (CD Function Only Active)

 Front Key : STOP  RCU Key :STOP

2. Check Version and Option code

 Front Key : STOP  RCU Key : PLAY/PAUSE  You can change [Audio MCU Version <-> CD Controller Version <-> EEPROM Option] by SKIP+/-.

3. Clear EEPROM

 Front Key : STOP  RCU Key : SKIP- (CD Model), 0 (DVD Model)

4. Edit EEPROM

 Front Key : STOP  RCU Key : SKIP+  You can change the digit of option by SKIP+/-.  You can edit 0~f by REPEAT or PLAY/PAUSE key.

5. Measure Mode (Bypass)

 Front Key : STOP  RCU Key : 8  HW output measure

POWER ON

VFD “NO DISC” status

It is possible at any function. (ex. It is possible at VFD “NO USB” status, too.) This is an example.

Front ‘Stop’ + Remote control ‘ ’

push same timing during 5 s

FLD “OP00-…..”

Move to appropriate position

And make changes with remote control

“ , , , REPEAT” key.

Press ‘Stop’ Key

VFD “WRITE OK”

Front ‘Stop’ + Remote control ‘ ’

push same timing during 5 s

VFD “E2P CLR”

Completed

1-7

SERVICE INFORMATION FOR EEPROM

1. AUDIO PROGRAM

Download program file name must be MICOM_OM7560_YYMMDDX.HEX

If security program(Water Wall) is activated on PC, you must save the file to the USB storage device and disable the security software, then download the file to your set. Downloading file proceeds in the same way at USB1 function and USB2 function.

Caution:

When downloading the file, you should neither unplug the USB device, change to the other function, nor power off the device. USB device must be unplugged when the downloading process is completed.

ON VFD DISPLAY SCREEN

1) (Fast) Format USB device.

2) Copy Firmware file to USB device.

NO USB

Insert USB device at USB function.



MICOM UP



FINISH



AUTO POWER OFF

1-8

PROGRAM DOWNLOAD GUIDE

2. CD PROGRAM

Download program file name must be HG690_OM7560_YYMMDDX.bin

Caution:

When downloading the file, you should neither unplug the USB device, change to the other function, nor power off the device. USB device must be unplugged when the downloading process is completed.

ON VFD DISPLAY SCREEN

1) (Fast) Format USB device.

2) Copy Firmware file to USB device.

NO USB

Insert USB device at USB function.



FIRMWARE



FINISH



AUTO POWER OFF

1-9

3. EQ PROGRAM

Download program file name must be EQ_PRG.BIN

Caution:

When downloading the file, you should neither unplug the USB device, change to the other function, nor power off the device. USB device must be unplugged when the downloading process is completed.

ON VFD DISPLAY SCREEN

1) (Fast) Format USB device.

2) Copy Firmware file to USB device.

NO USB

Insert USB device at USB function.



EQ UP



FINISH



AUTO POWER OFF

1-10

SPECIFICATIONS

1-11

• GENERAL

Power requirements Refer to the main label. Power consumption Refer to the main label. Dimensions (W x H x D) 330 x 815 x 302 mm Net Weight (Approx.) 16.8 kg Operating temperature 5 °C to 35 °C (41 °F to 95 °F) Operating humidity 5 % to 90 % Bus Power Supply (USB) 5 V 500 mA x 2

• INPUTS

AUX IN 2.0 Vrms (1 kHz, 0 dB), 75 Ω, RCA jack (L, R) x 1 PORT IN 1.2 Vrms (3.5 mm stereo jack)

• TUNER

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

• AMPLIFIER

Stereo mode 300 W + 300 W (4 Ω at 1 kHz, THD 10 %) Front 300 W + 300 W (4 Ω at 1 kHz, THD 10 %) Woofer 400 W (3 Ω at 200 Hz, THD 10 %)

• CD

Frequency Response 100 to 20 000 Hz Signal-to-noise ratio 75 dB Dynamic range 75 dB

• Design and specifications are subject to change without notice.

1-12

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

DISASSEMBLY INSTRUCTIONS ..................................................................................................................... 2-2

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

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

2. MECHANISM DECK SECTION (DM19AC) .............................................................................................. 2-5

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

2-1

2-2

DISASSEMBLY INSTRUCTIONS

Figure 2

Figure 1

2) To disassemble the Front Panel, remove the two screws and disassemble.

1) When disassembling the Frame Top, do not rotate and disassemble by pulling upwards.

RMC

TOP

MAIN

SMPS

260L

476

475

251

255

254

464

252

464

253

256

258

259

464

475

256

A50

475

270

475

A51

464

271

272

273

A41

475

A47

475

263

475

A46

275

264

476

475

260R

265

476

267

521

475

521

262

475

269

266

475

274

A42

475

270

257

CABLE4

CABLE1

CABLE3

CABLE2

A44

A43

464

A60

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.

1439

A001

1002

1005

1001

1003

1004

1026

1043

A005

1016

1013

1015

1020

1439

1018

1019

1012

A006

1045

1049

1437

1024

1437

1011

1030

2. MECHANISM DECK SECTION (DM19AC)

3. PACKING ACCESSORY SECTION

801 Owner’s manual

803 Packing

802 Box

804 Bag

808 Batteries

825 FM antenna

900 Remote control

300 Power Cord

Optional Part

2-8

SECTION 3 ELECTRICAL

CONTENTS

ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2

1. NO POWER ............................................................................................................................................ 3-2

2. NO BOOTING WHEN POWER ON THE SET........................................................................................ 3-3

3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET ..................................................................... 3-4

4. NO BOOTING (IN CD/USB FUNCTION) ................................................................................................ 3-5

5. NO OPERATION OF MD ........................................................................................................................ 3-9

6. NO SOUND ........................................................................................................................................... 3-14

ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................. 3-22

1. POWER (SMPS) ................................................................................................................................... 3-22

2. MCS PART CHECK .............................................................................................................................. 3-25

3. FLD DISPLAY CHECK ......................................................................................................................... 3-26

4. PWM MODULATION CHECK ............................................................................................................... 3-27

5. POWER AMP PART CHECK ............................................................................................................... 3-28

6. TUNER / AUX FUNCTION CHECK ...................................................................................................... 3-29

7. TUNER FUNCTION CHECK................................................................................................................. 3-30

8. CD FUNCTION CHECK ........................................................................................................................ 3-31

9. DOUBLE USB FUNCTION ................................................................................................................... 3-32

WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-33

1. DSP (IC501) .......................................................................................................................................... 3-33

2. SDRAM (IC502) .................................................................................................................................... 3-34

3. SERVO (IC401) ..................................................................................................................................... 3-35

4. MOTOR DRIVER (IC400) ..................................................................................................................... 3-36

5. ADC (IC201) .......................................................................................................................................... 3-37

6. USB (CN502) ........................................................................................................................................ 3-37

7. BLUETOOTH (CN504) .......................................................................................................................... 3-38

WIRING DIAGRAM .......................................................................................................................................... 3-39

BLOCK DIAGRAMS ........................................................................................................................................ 3-41

1. SYSTEM BLOCK DIAGRAM ................................................................................................................ 3-41

2. POWER BLOCK DIAGRAM ................................................................................................................. 3-43

3. AUDIO PATH BLOCK DIAGRAM ......................................................................................................... 3-45

CIRCUIT DIAGRAMS ...................................................................................................................................... 3-47

1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-47

2. MAIN - CD DSP CIRCUIT DIAGRAM ................................................................................................... 3-49

3. MAIN - SUB MICOM CIRCUIT DIAGRAM ........................................................................................... 3-51

4. MAIN - POWER PART CIRCUIT DIAGRAM ........................................................................................ 3-53

5. MAIN - ADC/ DAC/ PWM CIRCUIT DIAGRAM .................................................................................... 3-55

6. MAIN - RF SERVO CIRCUIT DIAGRAM .............................................................................................. 3-57

7. MAIN - PWM/ AMP CIRCUIT DIAGRAM .............................................................................................. 3-59

8. MAIN - FAN & LED LIGHTING CIRCUIT DIAGRAM ........................................................................... 3-61

9. TOP FRONT CIRCUIT DIAGRAM ........................................................................................................ 3-63

10. JACK/ RMC CIRCUIT DIAGRAM ......................................................................................................... 3-65

11. FRONT LED CIRCUIT DIAGRAM ........................................................................................................ 3-67

CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-69

1. IC INPUT VOLTAGE ............................................................................................................................. 3-69

2. CAPACITOR VOLTAGE ....................................................................................................................... 3-70

3. CONNECTOR VOLTAGE ..................................................................................................................... 3-71

PRINTED CIRCUIT BOARD DIAGRAMS

....................................................................................................... 3-75

1. SMPS P.C.BOARD ............................................................................................................................... 3-75

2. MAIN P.C.BOARD ................................................................................................................................ 3-77

3. TOP FRONT P.C.BOARD .................................................................................................................... 3-81

4. JACK/ RMC P.C.BOARD ...................................................................................................................... 3-85

5. FRONT LED P.C.BOARD ..................................................................................................................... 3-85

3-1

3-2

ONE POINT REPAIR GUIDE

1. NO POWER

If the unit doesn’t work by no power problem, repair the set according to the following guide.

1-1. FUSE/ THERMISTOR/ BRIDGE DIODE

1-1-1. Solution

Please check and replace F901, TH901 or TH903, BD901 on SMPS board.

1-1-2. How to troubleshoot (Countermeasure)

1) Check if the fuse F901 is open or short-circuit.

2) Check if the NTC thermistor TH900 or TH903 is normal or open.

3) Check if the bridge diode BD901 is short-circuit by over current with a digital multi-meter.

1-1-3. Service hint (Any picture/ Remark)

< F901 >

If F901 is not short-circuit,

replace it with a same

speciﬁ cations one.

< BD901 >

If BD901 is short-circuit,

replace it with a new one.

If TH901 or TH903 is open,

replace it with a new one.

3-3

ONE POINT REPAIR GUIDE

NO POWER

If the unit doesn’t work by no PVDD problem, repair the set according to the following guide.

1-2. FUSE/ FET

1-2-1. Solution

Please check and replace F901, Q901 on SMPS board.

1-2-2. How to troubleshoot (Countermeasure)

1) Check if the fuse F901 is open or short-circuit.

2) Check the anode-cathod voltage of D951 with a digital multi-meter, it is normally 0.2 ~ 0.3 V.  If it doesn’t have any voltage, it’s destroyed. Replace it with a new one.

1-2-3. Service hint (Any picture/ Remark)

< SMPS circuit >

3-4

ONE POINT REPAIR GUIDE

2. NO BOOTING WHEN POWER ON THE SET

The set doesn’t work when press the power button on the top board or the remote control.

2-1. IC501

2-1-1. Solution

Replace IC501 on MAIN board.

2-1-2. How to troubleshoot (Countermeasure)

1) Check the +12 VA (CN202) and 3.3VA (IC503) in standby mode.  If there is no 12 VA, check the SMPS and if doesn’t appear 3.3 VA, check IC503.

2) Check +12 VA, +5.1 VA, 3.3 VA, DVCC_5V and DVCC_3.3V when power on the set.

If the set doesn’t work regardless of what the KEY1 changes high to low while pressing the power button.

X500 and X501 work normally but, if you can not power on the set, replace the IC501 with a new one

on the main board.

2-1-3. Service hint (Any picture/ Remark)

< MAIN board top view >

< MAIN board bottom view >

X500

(24 MHz)

X501

(32.768 kHz)

KEY1

(R518)

PWR_CTRL

R559

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LG OM7560 Schematic

Specifications and Main Features

Frequently Asked Questions

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