LG CM2760 Service Manual Download Page 45

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3-32

3-31

SOC

USB

controller

Audio

Decoder

MLC3730

PSU

SPK OUT
L/R=80 W x 2
At THD = 10 %
L/R = 4 ohm

DC/DC LDO

EUP3484*1

SY8088*2

AZ1117*1

+27.5 V /6.8 A

BT Module
MB8811C1

Power AMP

TAS5342A

UART

SDRAM

4 M*16

Address

Data

Portable In 3.5 mm

Series Flash

32 Mbit

SPI

IIC

PWM

Processor

TAS5538

Crystal

24 MHz

Crystal

32.768 kHz

Servo

BU9546

DA11

A; B; C; D; E; F

Motor Driver

AM5888

Load+/-

SP+/-

F+/-

SL+/-

SP; SL; Load; F

CD DI/DO

CD Busy

CD IIS

CD Reset

CD Mute

IIS

IIC

L/R PWM

L Channel

R Channel

2 CH ADC

PCM1808

AD Data

AD Clock

USB

D+/D-

0.5 A Current

Limit

TPS2041

USB Jack

VFD Driver

PT6324

VFD

BOE

VFD48-

1503FN

SPI

Touch Key

AS9059

IIC

Power

Key

Red

LED*26

FM IC

Si4703

FM L/R

IIC

Audio MUX

UTC4052

BLOCK DIAGRAM

Summary of Contents for CM2760

Page 1: ... 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 ...

Page 2: ...CONTENTS SECTION 1 GENERAL SECTION 2 CABINET MAIN CHASSIS SECTION 3 ELECTRICAL SECTION 4 REPLACEMENT PARTS LIST 1 1 ...

Page 3: ...SECTION 1 SUMMARY CONTENTS SERVICING PRECAUTIONS 1 3 ESD PRECAUTIONS 1 5 HIDDEN KEY MODE 1 6 SOFTWARE UPDATE GUIDE 1 6 SPECIFICATIONS 1 7 1 2 ...

Page 4: ...age 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 cot ton ...

Page 5: ... 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 ...

Page 6: ...t 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 mat...

Page 7: ... STATUS Front Play RMC Stop for 5s Front Play RMC Stop for 5s LOCKED UNLOCKED Power Disc Lock On Off POWER ON STATUS Front Play RMC SOUND EFFECT for 5s Front Play RMC SOUND EFFECT for 5s LOCKED UNLOCKED Demo ALL Key Lock POWER ON STATUS Demo Function Only Active Front Play RMC INFO for 5s Front Play RMC INFO for 5s KEY LOCK UNLOCKED BT Auto Power On Off POWER ON STATUS Front RMC Power for 5s Power...

Page 8: ...ORT 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...

Page 9: ...1 8 ...

Page 10: ...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 ...

Page 11: ...2 2 ...

Page 12: ...264 265 265 513 270 513 514 514 271 513 514 825 262 517 517 261 262 517 CABLE3 CABLE5 CABLE4 CABLE1 CABLE2 CABLE6 CABLE8 CABLE7 515 515 300 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 ...

Page 13: ......

Page 14: ...2 PACKING ACCESSORY SECTION 801 Owner s manual 900 Remote control 808 Batteries 804 Bag 802 Box Packing 803T Packing 803B ...

Page 15: ...3 SPEAKER SECTION A60R A60L ...

Page 16: ...EN CLOSE NG 3 17 3 READING DISPLAY CHECK ONLY CD DISPLAY 3 17 4 READING OK CHECK NO DISC DISPLAY 3 18 5 USB PART 3 22 WAVEFORMS OF MAJOR CHECK POINT 3 23 WIRING DIAGRAM 3 29 BLOCK DIAGRAM 3 31 CIRCUIT DIAGRAMS 3 33 1 MAIN SMPS CIRCUIT DIAGRAM 3 33 2 MAIN CD CIRCUIT 3 35 3 MAIN DSP CIRCUIT DIAGRAM 3 37 4 MAIN AMP TUNER CIRCUIT DIAGRAM 3 39 5 MAIN POWER CIRCUIT DIAGRAM 3 41 6 TOUCH CIRCUIT DIAGRAM 3...

Page 17: ...30 E13_VS S33IO 131 D1 4_VDD3 3IO 132 A 17_PD 15 133 A 16_PD 0 134 B 16_PD 1 135 B 15_PD 2 136 A 15_PD 3 137 A 14_PD 4 138 B 14_PD 5 139 B 13_PD 6 140 A 13_PD 7 141 E9_V D D 12C O R E 142 D 10_PN T R ST 143 D 13_PG PD 00 144 D 9_PTD I 145 D 12_PG PD 01 146 D 8_PTM S 147 E11_PG PD 02 148 D 7_PTC K 149 D 11_PG PD 03 150 E7_PT D O 151 D 6_PR T C K 152 A 12_PG PA 00 153 B 12_PG PA 01 154 B 11_PG PA 02...

Page 18: ... troubleshoot Countermeasure 1 Reassemble AMP IC heat sink heat sink screw must be assembled tightly 2 Still NG please check Q409 Q407 Q408 part out if it is not appear 12 V 3 If it is not appear 12 V check IC202 pin48 output is a high level 4 If not high voltage check whether IC202 damage flash is lost 2 1 3 Service hint Any picture Remark MAIN board top view IC202 IC202 Q408 Q408 Q407 Q407 ...

Page 19: ...SB insert USB no detect on the unit 3 1 NO DETECT 3 1 1 Solution Replace IC205 3 1 2 How to troubleshoot Countermeasure 1 Please check IC205 pin1 5 V 2 If it is not OK replace IC205 3 1 3 Service hint Any picture Remark MAIN board top view IC205 IC205 ...

Page 20: ...or S Protection 2 Check DC Voltage of speaker out Front Left channel JK300 pin2 1 Front Right channel JK300 pin4 3 3 Check resistor crack cold solder of PWM IC out R310 R313 R320 R322 4 If PWM IC out is ok speaker out has DC Voltage Replace IC301 AMP IC on MAIN board 4 1 3 Service hint Any picture Remark MAIN board top view IC300 PWM IC IC300 PWM IC IC301 AMP IC IC301 AMP IC R310 R313 R310 R313 R3...

Page 21: ...Check PVDD Voltage 27 V If PVDD abnormal Voltage Refer to SMPS Board repair guide 3 Check GVDD VDD Voltage 12 V of IC301 pin1 22 23 44 If 12 V system abnormal Voltage Refer to 12 V no power repair guide 4 Check impedance 4 Ω of speaker unit If Impedance of speaker unit has 1 Ω under replace speaker unit 5 If check point 2 3 4 is ok replace IC301 AMP IC on MAIN board 4 2 3 Service hint Any picture ...

Page 22: ...d 4 3 2 How to troubleshoot Countermeasure 1 Press the power button the display is normal no sound output B Protection 2 Check Voltage 3 3 V of AMP_Protect signal collector Q303 3 If collector Q303 is low 0 V Replace IC301 AMP IC on MAIN board 4 3 3 Service hint Any picture Remark MAIN board top view Q303 Q303 ...

Page 23: ...WER CIRCUIT No 27 V Replace F900 same fuse Replace NTC900 Replace BD900 Check or replace IC901 IC901 normal Is the Vcc 12 V 13 V supplied to IC901 pin5 F900 normal NTC900 normal BD900 normal NO NO NO NO YES YES YES YES YES YES The Main part IC400 IC401 is short ...

Page 24: ...eplace IC401 Check Q407 ZD400 Check VCC33 network the device a short circuit will cause no output Check whether IC301 damage Check IC400 pin4 voltage 5 V Check Q407 collector voltage 27 V Check D405 anode voltage 5 V Check Q408 collector voltage 15 V IC401 normal Q408 normal NO NO NO NO NO NO YES YES YES YES YES YES YES YES ...

Page 25: ...STB pin2 DATA pin1 CLK Check data output Check pin4 DO DATA input Replace the related part Replace the related part Replace the related part FLD light on Check CN500 pin3 11 voltage NO NO NO NO NO NO NO Check the related part Check CN500 DATA communication pin9 STB pin7 DATA pin8 CLK Check VFD PCB F F both terminals over 3 7 V Check power VEE over 33 V YES YES YES YES YES YES YES YES 2 FLD DISPLAY...

Page 26: ...DIO PART 3 TOUCH PAD CHECK Touch pad check OK OK OK Replace the related part Refer to Power part troubleshooting NO NO Check R652 C603 IC600 part circuit CN600 pin2 3 3 V Check IC600 pin8 SDA pin9 SCL Check IC600 pin5 3 3 V NO NO YES YES YES YES ...

Page 27: ...5538 pin11 CLK correlation network Replace the related part Check IC300 TAS5538 OK Replace the related part Replace the related part Check IC300 TAS5538 VDD Power pin9 14 35 50 Check IC300 TAS5538 pin11 CLK input NO NO NO NO Check output IC300 pin22 LRCK pin 23 CLK pin24 DATA Check IC300 TAS5538 input pin20 SDA pin21 SCL pin16 RESET Check PWM modulator output L_CH 38 39 R_CH 41 40 NO NO NO YES YES...

Page 28: ... to Power part troubleshooting Check resistance power IC301 R301 R335 R336 R300 Replace the related part Check input power of IC301 pin41 40 35 32 27 26 Check PWM modulator input IC301 pin6 8 16 18 Power IC301 pin28 31 36 39 output OK NO NO NO The Main power of 27 V Check IC301 pin1 22 23 44 12 V input Check output L300 L301 ...

Page 29: ...her CN500 contacts or not Replace the related part Refer to Power part troubleshooting Check IC303 NO NO NO Check FB308 FB309 R348 R338 C362 C374 Check IC302 pin16 5 V Check IC303 pin9 SDOUT YES YES YES 6 AUX FUNCTION CHECK Check IC302 CD4052 pin1 12 input waveform Check IC303 PCM1808 pin13 14 input waveform NO NO YES YES YES ...

Page 30: ...R356 C380 C384 R359 OK Replace the related part Refer to SMPS troubleshooting Check IC302 Refer to Power part troubleshooting NO NO NO NO Check X300 32 768 kHz Check IC302 pin13 output Check Tuner IC304 pin11 5 V pin10 3 3 V YES YES YES Check IC304 pin13 14 input waveform Check IC302 pin5 14 output waveform NO NO YES YES ...

Page 31: ...Check audio data IC100 pin35 LRCK pin36 BCLK pin34 DATA Check IC101 AM5888 Check pick up movement Check IC100 BU9546 Check connector CN102 OK Check CN102 pin3 Open pin1 Close DISC reading is OK If play audio output check Check Open Close NO NO NO NO Check voltage IC101 pin8 19 5 V YES YES YES YES YES YES YES YES YES YES 1 CD PART ...

Page 32: ...88 pin8 19 5 V NO Check voltage IC101 AM5888 pin9 MOT pin10 MOT NO YES YES YES 3 READING DISPLAY CHECK ONLY CD DISPLAY Check connector locking CN101 CN102 Defective IC200 Defective Main power supply Check IC202 Defective IC202 Check voltage IC101 AM5888 pin8 19 5 V NO Check voltage IC200 pin2 3 3 V Check IC201 pin19 17 16 38 37 CS CAS WE CLK CKE signal waveform NO NO YES YES YES YES ...

Page 33: ...ck CN101 pin3 4 SL SL Defective pick up or IC101 or IC100 Check CN100 pin10 LD Defective pick up or IC101 or IC100 Check CN101 pin1 2 SP SP Check CN100 pin14 15 T T Defective pick up or IC101 or IC100 Defective pick up or IC101 or IC100 Is reading OK Does sled move NO B A C D E NO Does lense move Up Down Does laser light Does spindle rotate NO NO NO NO NO NO NO NO YES YES YES YES YES ...

Page 34: ...ck up sled motor Defective pick up focus actuator Does SL waveform appear at IC101 pin11 IC100 pin15 waveform 2 sled motor Wave Does F waveform appear at IC101 pin14 IC100 pin13 waveform 3 focus coil drive wave Does SLIN waveform appear at IC100 pin4 waveform 2 sled drive wave Does VINFC waveform appear at IC100 pin1 waveform 3 focus drive wave NO NO A B NO NO Check CN101 line Check connector CN10...

Page 35: ...of IC100 RF IC supply voltage check Is 2 3 V pin9 LDO of IC100 laser control voltage check NO C NO Check connector CN101 line NO YES YES YES YES 4 4 READING OK CHECK D NO DISC DISPLAY Defective IC101 Defective IC100 Defective CN101 Defective pick up spindle motor Does SPIN waveform appear at IC101 pin17 waveform 4 spindle motor drive wave Does COVOUT waveform appear at IC100 pin16 waveform 4 spind...

Page 36: ...ective IC100 Defective CN100 Defective pick up or IC100 Does FE TE signal appear IC100 pin61 62 63 waveform 6 Does T waveform appear at IC101 pin15 waveform 5 tracking coil drive wave Does VINTK waveform appear at IC100 pin14 waveform 5 tracking drive wave NO E NO Check connector CN100 line NO NO YES YES YES ...

Page 37: ...01 pin2 D pin3 D Check JK501 pin5 6 5 V Check IC205 pin1 Check RB501 and CN202 Line connector Check IC202 pin62 64 OK Turn on USB Check CHECKING or USB display Check connector CN202 pin5 66 5 5 V Check RB501 pin1 5 5 V Check Reading OK NO NO NO NO NO YES YES YES YES YES ...

Page 38: ... 30 34 DURING POWER ON 1 MICOM INTERFACE WAVEFORM IC100 pin19 20 30 34 DURING NORMAL PLAY 1 2 3 4 2 3 4 1 pin30 RESET pin20 CD_RW pin34 DI IC100 pin46 DATA OUT pin19 DO IC100 pin45 DATA IN pin34 DI IC100 pin46 DATA OUT pin19 DO IC100 pin45 DATA IN pin20 CD_RW pin30 RESET 2 4 1 3 ...

Page 39: ...3 24 2 SLED DRIVE AND MOTOR WAVEFORM IC101 pin4 11 WHEN FOCUS SEARCH 2 SLED DRIVE AND MOTOR WAVEFORM IC101 pin4 11 DURING NORMAL PLAY 5 6 6 5 pin4 SLIN pin11 SL pin4 SLIN pin11 SL 5 6 ...

Page 40: ...MOTOR WAVEFORM IC401 pin1 14 WHEN FOCUS SEARCH FAILED OR THERE IS NO DISC ON TRAY 3 FOCUS DRIVE AND MOTOR WAVEFORM IC401 pin1 14 THERE IS DISC ON TRAY AND FOCUS SEARCH SUCCESS 7 8 8 7 pin1 VINFC pin14 F pin1 VINFC pin14 F 8 7 ...

Page 41: ...3 26 4 SPINDLE DRIVE AND MOTOR WAVEFORM IC101 pin17 23 WHEN TOC READING 5 TRACK DRIVE AND MOTOR WAVEFORM IC101 pin16 26 DURING NORMAL PLAY 9 10 11 12 pin17 SP pin23 SPIN pin26 TAO pin16 TA 10 9 12 11 ...

Page 42: ...3 27 6 RF FOCUS AND TRACKING ERROR WAVEFORM IC100 pin61 62 63 DURING NORMAL PLAY 7 AUDIO PART I2S WAVEFORM 13 14 15 16 17 18 19 pin63 RFOUT pin61 RFMON FE pin62 TE 13 15 14 16 17 18 19 ...

Page 43: ...3 28 ...

Page 44: ...3 30 3 29 WIRING DIAGRAM ...

Page 45: ...Mbit SPI IIC PWM Processor TAS5538 Crystal 24 MHz Crystal 32 768 kHz Servo BU9546 CD DA11 A B C D E F PD LD Motor Driver AM5888 Load SP F SL SP SL Load F CD DI DO CD Busy CD IIS CD Reset CD Mute IIS IIC L R PWM L Channel R Channel 2 CH ADC PCM1808 AD Data AD Clock USB D D 0 5 A Current Limit TPS2041 USB Jack VFD Driver PT6324 VFD BOE VFD48 1503FN SPI Touch Key AS9059 IIC IR Power Key Red LED 26 FM...

Page 46: ...3 V 10 SDA 0 3 6 V 0 3 3 V CN202 1 GND 0 V 0 V 2 GND 0 V 0 V 3 USB 0 3 3 V 0 2 V 4 USB 0 3 3 V 0 V 5 5V 0 5 5 V 5 14 V 6 5V 0 5 5 V 5 14 V Connector No Pin No Pin Name Voltage Voltage Spec Stress V CN203 1 DEBUG 0 3 3 V 3 3 V 2 GND 0 V 0 V CN300 1 GND 0 V 0 V 2 AUDIO IN 0 V 0 V 3 GND 0 V 0 V 4 AUDIO IN 0 V 0 V 5 AUDIO DETECT 0 3 3 V 0 3 25 V CN400 1 T SDA 0 3 6 V 3 V 2 T SCL 0 3 6 V 3 1 V 3 3 3V 0...

Page 47: ...3 50 3 49 PRINTED CIRCUIT BOARD DIAGRAMS 1 MAIN P C BOARD TOP VIEW BOTTOM VIEW NOTE Warning Parts that are critical with respect to risk of fire or electrical shock ...

Page 48: ...3 52 3 51 2 TOUCH P C BOARD 3 VFD P C BOARD TOP VIEW TOP VIEW BOTTOM VIEW BOTTOM VIEW ...

Page 49: ...3 54 3 53 4 USB P C BOARD 5 PORTABLE P C BOARD TOP VIEW TOP VIEW BOTTOM VIEW BOTTOM VIEW ...

Page 50: ...3 56 3 55 ...

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