LG MCD112 Service Manual Download

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MINI Hi-Fi SYSTEM

SERVICE MANUAL

MODEL : MCD112 (MCS112F)

CAUTION

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

Website http://biz.lgservice.com

MODE

: MCD

12
(MCS

12F)

SER

VICE MANUAL

Internal Use Only

P/NO : AFN72956656

APRIL, 2009

Summary of Contents for MCD112

Page 1: ...VICE MANUAL MODEL MCD112 MCS112F CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL Website http biz lgservice com MODEL MCD112 MCS112F SERVICE MANUAL Internal Use Only P NO AFN72956656 APRIL 2009 ...

Page 2: ...CTION CHECK 3 8 11 TUNER FUNCTION CHECK 3 9 12 TAPE FUNCTION CHECK 3 10 13 TAPE PLAY PART CHECK 3 11 14 TAPE REC PART CHECK 3 12 INTERNAL BLOCK DIAGRAM OF ICs 3 13 1 ES6838 3 13 2 HA12237F 3 14 3 PS9829B 3 15 4 PT6324 3 15 5 STR S6757IF1905 3 16 6 TAS5142 3 17 7 U1739EJ2V1UD00 KF2_E 3 18 WIRING DIAGRAM 3 19 BLOCK DIAGRAMS 3 21 1 SMPS BLOCK DIAGRAM 3 21 2 MAIN FRONT BLOCK DIAGRAM 3 23 SCHEMATIC DIA...

Page 3: ...sted 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...

Page 4: ...ench 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 1MΩ 6 Care should be taken not to permit the laser p...

Page 5: ...s 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 short...

Page 6: ...e function on display window To cancel it press or DEMO again 5 Headphone jack Connect a headphone plug ø3 5 mm into the jack to listen to the sound through headphones not supplied 6 CD tray 7 XTS PRO The function creates the optimum sound for you to play of the original sound Each time you press XTS PRO XTS PRO ON or XTS PRO OFF is displayed in turn The XTS Pro function will not be operated when ...

Page 7: ...s being repeated 5 Use when playing a cassette tape 6 Sound quality adjustment You can select a desired sound mode by using EQ 7 Play any track on a CD Press the corresponding number buttons on the remote control 8 Temporarily stop the sound Press the button again to return to the sound 9 To change the functions Change the functions between FM AM CD AUX USB or TAPE 10 Dimm the display light 11 For...

Page 8: ...z AMPLIFIER Output Power 100W 100W MCD212 Model 50W 50W MCD112 Model T H D 0 5 Frequency Response 40 20000Hz Signal to noise ratio 75dB CD Frequency response 40 20000Hz Signal to noise ratio 75dB Dynamic range 75dB SPEAKERS MCS212F Type Bass Reflex 2 Way 2 Speaker Impedance 4Ω Rated Input Power 100W Max Input Power 200W Net Dimensions WxHxD 220 x 342 x 270mm Net Weight 1EA 3 46kg MCS112F Type Bass...

Page 10: ...47 A46 266 263 305 451 267 289 456 450 264 458 450 450 450 290 290 454 CABLE2 CABLE4 CN806 P9701 P9702 260 CD MAIN SMPS 291 257 255 259 253 253 254 450 N N C 450 450 A00 CABLE1 CABLE5 CN201 CABLE3 A43 A40 FRONT Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 11: ...PULLEY MAYBE CHANGED FORWOW FLUTTERWHEN NECESSARY RING FW MAYBE ADDED FORWOW FLUTTERWHEN NECESSARY 001 002 006 007 008 016 017 018 019 020 003 A00 009 009 A02 A01 011 013 022 025 015 023 Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 12: ... A S DECK RING FW MAYBE ADDED FORWOW FLUTTERWHEN NECESSARY 013 011 009 009 003 008 015 022 023 024 016 017 018 019 020 007 A03 A00 Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 13: ...166 417 167 416 177 175 172 170 419 417 418 418 190 189 188 A30 A32 A26 181 187 186 184 421 421 185 156 155 153 173 168 163 162 441 440 422 A35 417 Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 14: ...AKER EXPLODED VIEW MODEL MCS112F 850L 850R 853 855 854 852 851 A80B A80L A80R A80AL A80AR 856 WIRE80 Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 18: ...S YES Replace IC 901 902 Check IC901 902 Check the fuse F901 NO NO NO YES Check short of P9701 P9702 line Replace the fuse Check the DC V of C905 If DC V is over 400V NO Check BD901 LF901 902 Check the DC V of C981 C945 If DC V is 6 1V NO Check short of P9702 line YES YES Chcek the DC V of C950 C951 If DC V is in 31 5V NO Check short of P9701 line Chcek the DC V of C909 C903 C921 If DC V is in 14 ...

Page 19: ...k the PIN3 of P9702 If DC V is over 28V 2 Check power circuit Trouble shooting NO OK 4 MICOM PART CHECK I MICOM part check I OK OK YES YES Check P SENS P7904 _PIN6 NO Refer to SMPS troubleshooting YES YES YES Check both end voltage of IC101 KIA7042 Check if input voltage of IC101 KIA7042 is over 5V YES NO Check the periphery of IC101 KIA7042 NO YES Check if IC101 KIA7042 of output voltage is over ...

Page 20: ...5V Check Q102_base 0 6V HIGH Check if IC103_PIN8 and IC100_PIN19 20 59 are 5V NO NO YES YES Check if voltage of P7904_PIN5 is 5 6V NO Refer to SMPS troubleshooting YES YES YES OK YES Check both end voltage of D101 YES YES Check D101 NO Check if output of D101 1SR35 is 5V YES YES YES YES Check IC101 Q102_collector 0 6V LOW OK Check if output of IC101 KIA7042 is over 4 3V OK NO Replace IC101 NO Repl...

Page 21: ...rved Only for training and service purposes LGE Internal Use Only Check IC100 78KOKF2 _ PIN 22 24 OK YES YES Refer to micom troubleshooting Check micom voltage 5V PIN22 DATA PIN24 CLK NO NO YES Replace micom Check micom NO YES OK 6 IC103 KS4CD21CS CHECK ...

Page 22: ... Check P7904_PIN1 2 3 voltage input NO Check P3702 connection NO If voltage is not 5V check input and output of D319 1SR35 YES Check P3702 connection and power Pin1 FL 22 Pin2 FL 26 Pin3 VKK over 26V YES YES YES YES OK OK 76 PIN DO Check DATA in Check IC100 NO IC100 75 PIN STB 77 PIN 4PIN DI 78 PIN 1PIN CLK Check data output IC100 Check IC301 DATA communication PIN PIN 75PIN 3PIN STB 76PIN 2PIN D ...

Page 23: ...29 PIN86 CLK input check NO Check FB614 BEAD input output and voltage NO Check X601 12 288MHz Replace X601 OK NO OK YES YES NO Replace FB614 NO Check IC605_ PIN2 output YES OK YES OK Replace IC605 NO Check R680 470Ω output Replace R680 NO Check IC604 PS9829 DATA input Check each LINE registor output NO Check IC604 PS9829 DATA input 78 PIN DATA 79 PIN CLK Check PWM modulator output FL 75 74 FR 71 7...

Page 24: ...00 R701 702 726 727 NO Check each IC700 701 702 703 PIN1 17 18 19 36 12V input Refer to SMPS troubleshooting YES YES YES NO P7905_3PIN 12V PIN13 14 15 35V YES Replace the coils YES NO Check output line coil Check PWM modulator input Each IC PIN4 6 14 16 YES Power IC700 701 702 703 PIN20 27 29 34 output Check each IC700 701 702 703 PIN21 26 29 34 input voltage OK 9 POWER AMP PART CHECK ...

Page 25: ...IC301 _ PIN83 84 commucation NO NO YES Replace IC200 YES YES YES Check IC200 BU4052 _ PIN4 11 input waveform Check IC200 BU4052 _PIN16 VDD PIN8 VSS power Refer to SMPS troubleshooting NO NO YES Replace IC801 OK YES YES Check IC801 MC4580 _PIN 2 6 input waveform Check IC801 MC4580 _PIN4 VSS PIN8 VDD power Check IC200 BU4052 _ PIN3 13 output waveform Check JK800 connection ...

Page 26: ... PIN16 VDD PIN8 VSS power NO Check IC200 BU4052 _PIN3 13 output waveform and IC601 BU4052 _PIN2 15 input waveform Check TUNER module voltage PIN2 9V YES YES YES YES NO Check TUNER module TU601 operation YES Check IC801 MC4580 _ PIN4 VSS PIN8 VDD power YES NO Check IC801 MC4580 _ PIN2 6 input waveform Replace IC200 Replace IC200 Replace IC801 Check IC200 BU4052 _PIN1 12 input waveform OK ...

Page 27: ...ck YES Check IC200 BU4052 _ PIN16 VDD PIN8 VSS power YES YES YES NO Check IC200 BU4052 _PIN2 15 input waveform Check IC200 BU4052 _ PIN16 VDD PIN8 VSS power YES NO Check IC801 MC4580 _ PIN2 6 input waveform YES Replace IC200 Replace IC200 Replace IC200 Check IC200 BU4052 _PIN3 13 output waveform and IC601 BU4052 _ PIN2 15 input waveform YES TAPE PCB ASS Y OK ...

Page 28: ...e deck mechanism NO NO YES YES Check A deck head input IC201_PIN32 39 and B deck head input IC201_PIN34 37 YES YES YES YES Check IC201_ PIN5 26 signal output Check IC201 HA12237 _PIN16 12V input Check A B deck head input NO Refer to SMPS troubleshooting Check IC202_PIN10 HIGH NO Check IC201_PIN14 mute operation Replace IC201 NO YES OK Check IC201 YES Replace IC202 NO YES OK OK Check IC202 ...

Page 29: ...00_PIN23 HIGH NO NO YES YES Check IC201_ PIN7 24 record input Check P2203_PIN5 3 input and PIN8 erase input YES YES YES YES YES Check L203_PIN2 3 oscillation Check IC604 PS9829 _PIN49 52 PWM output Check Q205 D1304 _ base HIGH Replace IC201 NO NO Check IC201_ PIN10 21 output Check IC100_PIN23 HIGH NO Refer to PWM modulation troubleshooting OK YES Replace IC202 YES OK OK ...

Page 30: ...1 ES6838 SDRAM ROM Interface GPIO Gateway DMA Controller Huffman Decoder ROM DRAM Interface RAM Video Processor TV Encoder VDAC HDMI I F Display OSD SPU Controller Scaler DeIntelacer 16 K Cache 32 Bit RISC Processor Audio ADC Serial Audio Interface Audio DAC USB DVD Descrambler Transport ATAPI Servo Controller RF 8051 µController DSC ECC Digital PLL ...

Page 32: ...face I2 C SPI Mic Input Processor Input Mapper Sample Rate Converter Input Output MUX Serial Audio Output Interface Down Mixer Mixer 4 Band EQ Bass Manager Main Volume Trim Volume Serial Audio Output Interface PWM Modulator POP NR Power Supply Output Mapper PLL Reset Power Down Automatic Gain Limiter 4 PT6324 SG1 KS1 SG2 KS2 SG3 KS3 SG4 KS4 SG5 KS5 SG6 KS6 SG7 KS7 SG7 KS7 SG8 KS8 SG9 KS9 SG10 KS10...

Page 33: ...aining and service purposes LGE Internal Use Only 5 STR S6757IF1905 4 Vcc Start Stop Burst OSC Protection latch DRIVE Reg Delay Burst Control BSD OCP GND S D FB FB OCP BD SS OLP BD Q Q S S R R MaxON R Q S OLP Reg Iconst Soft Start Counter Bottom Selector 5 7 6 3 2 1 OVP ...

Page 34: ...ESET_AB RESET_CD System Power Supply Hardwire Mode Control PVDD GVDD 12 V VDD 12 V GND Hardwire OC Limit M1 M3 PVDD Power Supply Decoupling 32 V 12 V GND VAC PWM_A PWM_C PWM_D PWM_B VALID M2 Left Channel Output Right Channel Output Input HúBridge 1 Input H Bridge 2 GVDD VDD VREG Power Supply Decoupling 4 PVDD_A B C D GND_A B C D GVDD_A B C D 4 4 VDD GND VREG AGND OC_ADJ Bootstrap Capacitors 2nd Or...

Page 35: ...control PCL P140 EXLVI P120 VDD EVDD VSS EVSS FLMD0 16 bit timer event counter 00 TO00 TI010 P01 TO01 TI011 P06 TI000 P00 TI001 P05 TOH0 P15 TOH1 P16 TI50 TO50 P17 TI51 TO51 P33 RxD0 P11 TxD0 P10 RxD6 P14 TxD6 P13 SI10 P11 SO10 P12 SI11 P03 SO11 P02 SCK11 P04 SCK11 P05 SIA0 P143 SOA0 P144 SCKA0 P142 STB0 P145 BUSY0 P141 EXSCL0 P62 SDA0 P61 SCL0 P60 AVREF RxD6 P14 LINSEL INTP0 P120 INTP1 P30 to INT...

Page 36: ... DECK MECHANISM 30P 4P 8P 3P 13P 29P USB MIC H P FRONT PCB SMPS PCB 15P 4P Total CNT Q ty 14ea 1 SMPS MAIN 2ea 2 MAIN DVD 2ea 3 MAIN FRONT 1ea 4 FRONT DVD 1ea 5 DVD MD 5ea 6 DECK MECHA 3ea RED RED Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 37: ... 1 MAIN Switch IC 2 T R A N S 2 FL1 FL2 4 5V 12V 12V 78R12 5V P SENS 6 1V KIA278R05 P9702 P9701 FEED BACK AMP 31 5V 3 5V 278R35 31 5V VKK RECTIFICATION SMOOTHING CIRCUIT FEED BACK Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

Page 38: ...MCLK LRCK BCK SD_OUT 7 ADC_RST D D 5V G 14 3178MHz 16 9344MHz ND PICK UP PICK UP MOTOR MOTOR MD MD AUX2 4 4 4 3 LC78692W DSP IC OTI6888 VER A9 AUX2 _L R AM5810 MOTOR DRIVER TX RX A B C D E F 74HCT244 BUFFER RX TX EIGHT KINDS EXCEPT CD IN STDATA STCK STREQ 3 FDO TDO SL SP OP CL TA FA SLDO SPDO FSEQ WRQ CD_DO H P MIC CLK DATA 5V GND CLK DATA MIC _SIG MIC _SIG 5 4 4 4 4 4 4 4 78F0546 AUDIO MICOM KS24...

Page 39: ... REPLACED ONLY WITH TYPES IDENTI CAL TO THOSE IN THE ORIGINAL CIRCUIT SPECIAL COMPONENTS ARE SHADED ON THE SCHEMATIC FOR EASY IDENTIFICATION THIS CIRCUIT DIAGRAM MAY OCCASIONALLY DIFFER FROM THE ACTUAL CIRCUIT USED THIS WAY IMPLEMENTATION OF THE LATEST SAFETY AND PERFORMANCE IMPROVE MENT CHANGES INTO THE SET IS NOT DELAYED UNTIL THE NEW SERVICE LITERATURE IS PRINTED 1 Shaded parts are critical for...

Page 50: ...voltage PN805 PIN22 CLOSE PIN23 OPEN YES NO Reading Display check Connector check PN802 PN803 PN804 CN806 PN814 NO Check micom interface circuit PN805 CE BTL MUTE CD IN CD OUT CLK WRQ FSEQ YES NO Reading OK check Connector check PN801 PN802 NO YES If PALY AUDIO OUTPUT check Check PN805 audio data PIN10 DA_LRCK IC801 PIN60 LRSY PIN11 DA_BCK IC801 PIN59 DATACLK PIN12 DA_DATA0 IC801 PIN58 DATA NO Che...

Page 51: ...04 PN814 YES YES YES YES Check power supply circuit PN805 CN806 CN806 PIN1 12V PIN2 6 3V PN805 PIN8 5V_AD Defective main power supply NO Check voltage change LO LO OF IC803 PN805 PIN23 OPEN PIN22 CLOSE Defective IC803 Defective mechanism NO Check voltage change of OPEN CLOSE IC803 INPUT voltage PIN6 12V PIN7 6 3V PN805 PIN2 BTL_MUTE 23 OPEN 22 CLOSE Defective micom NO ...

Page 52: ...806 PIN1 12V PIN2 6 3V PIN4 5V PN805 PIN8 5V_AD Defective connector or main power supply Defective IC804 NO Check micom interface circuit PN805 PN805 PIN1 3 4 15 19 26 signal check 1 CE 3 DI 4 CLK 15 D0 19 RST 18 FSEQ 26 WRQ PIN3 DI From DSP to micom PIN15 DO From micom to DSP Check the waveform 1 Defective micom or connector Defective IC804 NO Check voltage The PIN2 of IC804 IC804 PIN2 3 3V NO De...

Page 53: ...ove NO NO Check PN802 PIN3 4 SL SL 1 3 READING OK CHECK NO DISC DISPLAY Does lense move UP DOWN YES A YES Defective pick up or IC802 or IC801 NO NO Check PN801 PIN13 16 FA FA B Defective pick up or IC802 Does laser light NO NO Check PN801 PIN10 LD YES C Defective pick up or IC802 or IC801 Does spindle rotate NO NO Check PN802 PIN3 6 SP SP YES D Defective pick up or IC802 or IC801 NO NO Check PN801...

Page 54: ...1 4 READING OK CHECK A NO DISC DISPLAY YES YES A Defective IC802 NO Defective PN802 connector Defective pick up sled motor Check PN802 connector line YES Defective IC801 Does FA waveform appear at IC802 PIN16 and PN801 PIN13 waveform 3 focus coil drive wave Does fain waveform appear at IC802 PIN25 waveform 3 focus drive wave NO NO 1 5 READING OK CHECK B NO DISC DISPLAY YES YES B Defective IC802 NO...

Page 55: ...f PN801 laser supply voltage check Is 3 3V applied to PIN30 36 39 41 61 68 75 of IC801 RF IC supply voltage check NO NO 1 6 READING OK CHECK C NO DISC DISPLAY YES YES Defective IC801 Is 2 3V PIN18 LDO of IC801 laser control voltage check NO YES C Defective Q801 or D801 NO Defective PN801 connector Defective pick up laser part Check PN801 connector line YES ...

Page 56: ... IC801 Does SP waveform appear at IC802 PIN11 and PN802 PIN5 waveform 4 spindle motor drive wave Does spin waveform appear at IC802 PIN6 waveform 4 spindle drive wave NO NO 1 7 READING OK CHECK D NO DISC DISPLAY YES YES D Defective IC802 NO Defective PN802 connector Defective pick up spindle motor Check PN802 connector line YES ...

Page 57: ...801 Does TA waveform appear at IC802 PIN17 and PN801 PIN14 waveform 5 tracking coil drive wave Does tain waveform appear at IC802 PIN22 waveform 5 tracking drive wave NO NO 1 8 READING OK CHECK E NO DISC DISPLAY YES YES E Defective IC802 Does ARF signal appear IC801 PIN 2 waveform 6 NO Defective pick up or IC801 Check PN802 connector line NO Defective PN802 connector YES YES NO Defective pick up o...

Page 58: ...r supply circuit CN806 Check micom interface circuit PN805 PIN13 RX IC805 PIN49 TXD PIN14 TX IC805 PIN33 RXD NO NO Check PN810 PIN2 D 3 D Check OTI6888 IC805 Connector check CN806 OK YES Checking or USB display check NO YES Check PN810 1PIN 5V Reading OK check NO Check signal STCK STREQ STDATA STCK IC805 PIN52 IC801 PIN55 STREQ IC805 PIN53 IC801 PIN54 STDATA IC805 PIN54 IC801 PIN56 If PLAY AUDIO O...

Page 59: ...wer on PIN26 WRQ PIN19 RESET PIN3 DI IC801 PIN46 DATA OUT PIN15 DO IC801 PIN45 DATA IN 1 MICOM INTERFACE WAVEFORM PN805 PIN26 19 3 15 during normal play PIN26 WRQ PIN19 RESET PIN3 DI IC801 PIN46 DATA OUT PIN15 DO IC801 PIN45 DATA IN 1 MICOM INTERFACE WAVEFORM PN805 PIN4 1 18 during power on PIN4 CL PIN1 CE PIN18 FSEQ 1 MICOM INTERFACE WAVEFORM PN805 PIN4 1 18 during normal play PIN4 CL PIN1 CE PIN...

Page 60: ...n focus search PIN5 SLIN PIN13 SL 2 SLED DRIVE AND MOTOR WAVEFORM IC802 PIN5 13 during normal play PIN5 SLIN PIN13 SL 3 FOCUS DRIVE AND MOTOR WAVEFORM IC802 PIN25 IC802 PIN16 When focus search failed or there is no disc on tray PIN25 FAO PIN16 FA 3 FOCUS DRIVE AND MOTOR WAVEFORM IC802 PIN25 IC802 PIN16 There is disc on tray and focus search success PIN25 FAO PIN16 FA ...

Page 61: ...ernal Use Only 4 SPINDLE DRIVE AND MOTOR WAVEFORM IC802 PIN6 11 when TOC reading PIN6 SPIN PIN11 SP 5 TRACK DRIVE AND MOTOR WAVEFORM IC802 PIN22 IC802 PIN17 during normal play 6 RF FOCUS AND TRACKING ERROR WAVEFORM IC801 PIN2 10 16 during normal play PIN2 RFOUT PIN 16 TE PIN10 RFMON FE PIN22 TAO PIN17 TA ...

Page 64: ...4 17 4 18 PRINTED CIRCUIT BOARD DIAGRAM CD P C BOARD TOP VIEW BOTTOM VIEW Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only ...

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