LG CM9550 Schematic

SERVICE MANUAL

CAUTION

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

SERVICE MANUAL

Internal Use Only

Website http://biz.lgservice.com

JULY, 2015P/NO : AFN77277004

MODEL:

CM9550

(CM9550, NS9550F/W)

MODEL: CM9550 (CM9550, NS9550F/W)

Mini Hi-Fi System

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

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

PROGRAM DOWNLOAD & UPDATE GUIDE ................................................................................... 1-8

SPECIFICATIONS ..................................................................................................................................... 1-12

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

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-

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. Bluetooth DUT

 Front Key : STOP  RCU Key : PROGRAM  Bluetooth model only

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

 Front Key : STOP  RCU Key : EQ

7. Amp Clip On/Off

 Front Key : STOP  RCU Key : Mute

Amp Clip Mode Change (Amp Clip On --> Amp Clip Off --> Level Down display)

1-6

SERVICE INFORMATION FOR EEPROM

POWER ON

It is possible at any function.

FLD “NO DISC” status

Remote control ‘ ’ + Front ‘STOP’ push same timing during 5 seconds.

FLD “op0-…..”

Move to appropriate position and

make changes with remote control.

( , , , REPEAT)

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

Press STOP key

FLD “WRITE OK”

Remote control ‘ ’ +

Front ‘STOP’ push same timing.

FLD “e2p clr”

Completed

1-7

PROGRAM DOWNLOAD & UPDATE GUIDE

1. AUDIO PROGRAM

Download program file name must be MICOM_CM9550_YYMMDDX.HEX

If security program (Water Wall) is activated on your 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

NO USB

Insert USB device at USB function.



MICOM UP



FINISH



Auto POWER OFF

1-8

2. CD PROGRAM

Download program file name must be HG580_CM9550_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

NO USB

Insert USB device at USB function.



MCS UP



FINISH



Auto POWER OFF

1-9

3. DEMO PROGRAM

Download program file name must be DEMO_DAT.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

NO USB

Insert USB device at USB function.



DEMO UP



FINISH



Auto POWER OFF

1-10

4. 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

NO USB

Insert USB device at USB function.



EQ UP



FINISH



Auto POWER OFF

1-11

SPECIFICATIONS

• GENERAL

Power requirements Refer to the main label. Power consumption Refer to the main label. Dimensions (W x H x D) (290 x 349 x 370) mm Net Weight (Approx.) 5.9 kg Operating temperature 5 °C to 35 °C (41 °F to 95 °F) Operating humidity 60 % Bus Power Supply 5 V 500 mA

• INPUTS

AUX IN 2.0 Vrms (1 kHz, 0 dB), 600 Ω, RCA jack (L, R) PORT. IN 1.2 Vrms (3.5 mm stereo jack) MIC 27 mV

• TUNER

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

• CD

Frequency Response 40 to 20 000 Hz Signal-to-noise ratio 75 dB Dynamic range 80 dB

• AMPLIFIER

Stereo mode 470 W x 2 (THD 20 %) Surround mode Front 470 W x 2 (THD 20 %) Surround 470 W x 2 (THD 20 %) Subwoofer 460 W x 2 (THD 20 %)

• FRONT SPEAKER

Type 2 Way 2 Speaker Impedance 6 Ω Rated Input Power 470 W Max. Input power 940 W

• SURROUND SPEAKER

Type 1 Way 1 speaker Impedance 6 Ω Rated Input Power 470 W Max. Input power 940 W Net Dimensions (W x H x D) (425 x 505 x 351) mm Net Weight 13.2 kg

• SUBWOOFER

Type 1 Way 1 speaker Impedance 6 Ω Rated Input Power 460 W Max. Input power 920 W Net Dimensions (W x H x D) (425 x 505 x 354) mm Net Weight 12.7 kg

• Design and specifications are subject to change without notice.

1-12

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

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

1. CABINET AND MAIN FRAME SECTION (CM9550) ................................................................................ 2-3

2. MECHANISM DECK SECTION (DP17TM2) ............................................................................................ 2-5

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

4. SPEAKER SECTION ................................................................................................................................ 2-8

2-1

2-2

EXPLODED VIEWS

1. CABINET AND MAIN FRAME SECTION (CM9550)

443

FRONT

A43

MAIN

SMPS

266

A46

267

443

252

251

252

253

A42

A47

443

268

270

269

300

272

271

443

B/T

A52

CABLE4

A44

259

MIC & PTB

443

CABLE3

CABLE1

CABLE2

291

NFC Tag

A56

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. MECHANISM DECK SECTION (DP17TM2)

1026

1439

A001

1002

1005

1001

1049

1437

1024

1030

1024

1043

1045

A005

A006

1016

1013

1015

1020

1024

1003

1439

1018

1019

1011

1012

1437

1004

3. PACKING ACCESSORY SECTION

801 Owner’s Manual

836A Rubber Foot (Rear)

836L Rubber Foot (Left)

836R Rubber Foot (Right)

825 FM Wire Antenna

808 Battery

900 Remote Control

803 Packing

804 Bag

803 Packing

802 Box

4. SPEAKER SECTION

4-1. FRONT SPEAKER (NS9550F)

• LEFT SPEAKER

A60L

A61

LED SUB

A62

652

651

LED

MAIN

FRONT SPEAKER (NS9550F)

• RIGHT SPEAKER

A60R

A61

LED SUB

A62

652

651

LED

MAIN

4-2. SUBWOOFER SPEAKER (NS9550W)

A90

A91

952

951

LED SUB

LED

MAIN

A92

952

SECTION 3

ELECTRICAL

CONTENTS

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

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

2. NO BOOTING WHEN POWER ON THE SET........................................................................................3-4

3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET ..................................................................... 3-5

4. NO BOOTING IN CD/USB FUNCTION ..................................................................................................3-6

5. NO OPERATION OF MD (DRIVING THE SERVO MOTORS) ............................................................3-11

6. NO SOUND ...........................................................................................................................................3-16

7. AUDIO OUTPUT IS SMALL OR NO AUDIO OUTPUT ........................................................................ 3-22

8. NO POWER ON (STANDBY LED IS BLINKING) ................................................................................. 3-23

9. SPEAKER NO AUDIO ..........................................................................................................................3-24

ELECTRICAL TROUBLESHOOTING GUIDE .................................................................................................3-25

1. POWER SUPPLY ON SMPS BOARD ..................................................................................................3-25

2. SYSTEM PART .....................................................................................................................................3-29

3. NO AUDIO PART ..................................................................................................................................3-30

4. NO LIGHTING (WOOFER SPEAKER) ................................................................................................. 3-35

WAVEFORMS OF MAJOR CHECK POINT ....................................................................................................3-36

WIRING DIAGRAM ..........................................................................................................................................3-41

BLOCK DIAGRAMS ........................................................................................................................................3-43

1. SMPS BLOCK DIAGRAM .....................................................................................................................3-43

2. MAIN SYSTEM BLOCK DIAGRAM ......................................................................................................3-45

3. MAIN POWER BLOCK DIAGRAM .......................................................................................................3-47

CIRCUIT DIAGRAMS ......................................................................................................................................3-49

1. SMPS - POWER #1 CIRCUIT DIAGRAM ............................................................................................3-49

2. SMPS - POWER #2 CIRCUIT DIAGRAM ............................................................................................3-51

3. MAIN - CD DSP CIRCUIT DIAGRAM ...................................................................................................3-53

4. MAIN - RF / SERVO CIRCUIT DIAGRAM ............................................................................................ 3-55

5. MAIN - ADC / PWM CIRCUIT DIAGRAM ............................................................................................. 3-57

6. MAIN - AMP CIRCUIT DIAGRAM.........................................................................................................3-59

7. FRONT VOLUME CIRCUIT DIAGRAM ................................................................................................ 3-61

8. MIC & PORTABLE CIRCUIT DIAGRAM ..............................................................................................3-63

9. FRONT SPEAKER MAIN CIRCUIT DIAGRAM ....................................................................................3-65

10. FRONT SPEAKER SUB CIRCUIT DIAGRAM ...................................................................................... 3-67

11. WOOFER SPEAKER MAIN CIRCUIT DIAGRAM ................................................................................3-69

12. WOOFER SPEAKER SUB CIRCUIT DIAGRAM .................................................................................. 3-71

CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-73

1. CONNECTORS .....................................................................................................................................3-73

2. CAPACITORS .......................................................................................................................................3-74

PRINTED CIRCUIT BOARD DIAGRAMS .......................................................................................................3-75

1. SMPS P.C.BOARD (TOP VIEW) .......................................................................................................... 3-75

2. SMPS P.C.BOARD (BOTTOM VIEW) .................................................................................................. 3-77

3. MAIN P.C.BOARD (TOP VIEW) ...........................................................................................................3-79

4. MAIN P.C.BOARD (BOTTOM VIEW) ...................................................................................................3-81

5. FRONT VOLUME & MIC & PORTABLE P.C.BOARD (TOP VIEW).....................................................3-83

6. FRONT VOLUME & MIC & PORTABLE P.C.BOARD (BOTTOM VIEW).............................................3-85

7. FRONT SPEAKER MAIN/SUB & WOOFER SPEAKER MAIN/SUB P.C.BOARD (TOP VIEW) ..........3-87

8. FRONT SPEAKER MAIN/SUB & WOOFER SPEAKER MAIN/SUB P.C.BOARD (BOTTOM VIEW) ..3-87

3-1

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 / BRIDGE DIODE / THERMISTOR

1-1-1. Solution

Please check and replace F901, BD901, TH900, TH901 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 bridge diode BD901 is short-circuit by over current with a digital multi meter.

3) Check if the NTC thermistor TH900, TH901 is normal or open.

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

< F901 >

If F901 is not short-circuit,

replace it with a same

speciﬁ cations one.

If BD901 is short-circuit,

replace it with a new one.

< BD901 >

3-2

< TH900, TH901 > If TH900, TH901 is open, replace it with a new one.

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. NO AMP POWER

1-2-1. Solution

Please check and replace F911, Q905, Q906 on SMPS board.

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

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

2) Check the Drain-Source or Drain-Gate, Gate-Source Resistance of Q905, Q906 with a digital multi-meter.  If it is short condition, it’s destroyed. Replace it with a new one.

(Please replace 2 FET at the same time although several FET is OK)

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

< F911 >

If F911 is not short-circuit,

replace it with a same speciﬁ cations one.

< Q905, Q906 >

If Q905, Q906 is short-circuit,

replace it with a new one.

3-3

ONE POINT REPAIR GUIDE

2. NO BOOTING WHEN POWER ON THE SET

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

2-1. MICOM (IC501)

2-1-1. Solution

Please check and replace IC501 on MAIN board.

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

1) Check the 5.6 VA (CN106) and DVCC 3.3 V(IC505) in standby mode.  If there is no 5.6 VA, check the SMPS and if doesn’t appear 3.3 V, check IC505.

2) Check 5.6 VA, +12 V, FL+, FL-, an +39 V when power on the set.

- If the set doesn’t work regardless of what the KEY2 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)

KEY1

(pin16)

X501

(32.768 KHz)

X500

(24 MHz)

PW R_ CTRL

(R5F7)

< MAIN board top view >

3-4

ONE POINT REPAIR GUIDE

3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET

When power on the set, any icons or characters on VFD are not displayed.

3-1. VFD (DIG300)

3-1-1. Solution

Please check and replace DIG300 on FRONT board.

3-1-2. How to troubleshoot (Countermeasure)

1) Check if 39V, FL+ and FL-are output from SMPS to VFD via the main board.

2) Check if the IC501 outputs VFD_RST, VFD_CLK, VFD_CS and VFD_DO to the front board.

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

VFD_RST

VFD_CS

VFD_CLK

VFD_DO

3-5

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