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 3-2

ELECTRICAL TROUBLESHOOTING GUIDE

1. SMPS BOARD

YES

YES

YES

YES

YES

No power.

Replace SMPS board.

Connect the open line.

Replace F901.

Check SMPS second part lines short.

Check 3.7 V lines short.

Replace PC951, PC972, IC901.

Check BD901 “+”

to “-” Pin impedance .

Check MAIN or AMP board short.

Replace PC972, IC902’s components.

Check around IC901’s components

(Short, Open).

Low impedance:

Replace IC901, BD901.

NO

NO

NO

NO

NO

Check the AC

line pattern.

Check fuse F901.

Check C963

voltage (5.6 V).

Check C978

voltage (3.9 V).

Check IC901

Vcc voltage (10 V ~ 30 V).

Summary of Contents for MDT505

Page 1: ...L MODEL MDT505 MDS505V W CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL MODEL MDT505 MDS505V W SERVICE MANUAL 0 1 0 2 SEPTEMBER 218 2 7 9 4 7 N F A O N P Website http biz lgservice com Internal Use Only ...

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

Page 3: ...ms 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 ...

Page 4: ...eplacing 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...

Page 5: ...es 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 co...

Page 6: ...keyÖ1Ö4Ö7Ö2 in order Use arrow key to move to appropriate position and make changes Press pause key once Change will be applied when power OFFÖON NAME OPT 1 OPT 2 OPT 3 OPT 4 OPT 5 OPT 6 OPT 7 OPT 8 OPT 9 OPT A DETECT NEW EEPROM OPTION EDIT SCREEN HEX A5 06 85 B4 00 08 91 01 80 00 1 5 SERVICE INFORMATION FOR EEPROM ...

Page 7: ...ll be rebooted with Complete message 2 How to update DVD program Update using CD 1 Copy DVD program ex LG_MDS715LD1_Version Rom to Root folder of CD and burn it ex P LG_MDS715LD1_0911180 Rom 2 Insert the CD to the SET then after a while the CD tray will be opened with upgrade information on the screen 3 Remove the CD and press PLAY key in remote controller 4 Remove and reconnect the power cable wh...

Page 8: ...nc negative RCA jack x 1 COMPONENT VIDEO OUT Y 1 0 V p p 75 Ω sync negative RCA jack x 1 Pb Pr 0 7 V p p 75 Ω RCA jack x 2 ANALOG AUDIO IN 0 6 Vrms 47 kΩ RCA jack L R x 1 PORT IN 0 5 Vrms 3 5 mm stereo jack TUNER FM Tuning Range 87 5 to 108 0 MHz or 87 50 to 108 00 MHz AM Tuning Range 522 to 1 620 kHz 520 to 1 710 kHz or 522 to 1 710 kHz AMPLIFIER Stereo mode 150 W 150 W 4 Ω at 1 kHz Surround mode...

Page 9: ... W W 0 0 3 r e w o p t u p n I x a M Net Dimensions W x H x D 240 x 387 x 336 mm g k 5 t h g i e W t e N Passive Subwoofer MDS505W r e k a e p s 1 y a W 1 e p y T 3 e c n a d e p m I Ω Rated Input Power 200 W W 0 0 4 r e w o p t u p n I x a M Net Dimensions W x H x D 261 x 331 x 409 mm g k 5 6 t h g i e W t e N ...

Page 10: ...AIN CHASSIS CONTENTS EXPLODED VIEWS 2 3 1 CABINET AND MAIN FRAME SECTION MDT505 2 3 2 TAPE DECK MECHANISM SECTION 2 5 3 DVD DECK MECHANISM SECTION DVM H1723 2 7 4 SPEAKER SECTION 2 11 5 PACKING ACCESSORY SECTION 2 13 2 1 ...

Page 11: ...2 2 MEMO ...

Page 12: ... 464 464 464 464 276 464 266 451 A00 272 464 464 464 250 262 261 261 260 251 254 255 256 257 252 258 253 259 464 464 464 464 271 269 264 265 267A 464 267 270L 263L 270R 263R CABLE1 CABLE3 CABLE4 CABLE5 CABLE2 VOLUME FRONT USB 274 273 463 275 iPod SMPS 464 464 464 B C D E F A J O G P I H A46 MAIN 463 463 463 N O 464 464 300 464 278 279 455 277 ...

Page 13: ...2 5 2 6 2 TAPE DECK MECHANISM SECTION A R A S RIGHT A R DECK A00 003 009 011 009 A02 015 007 001 037 A01 018 017 006 020 019 022 023 025 ...

Page 14: ...2 7 2 8 3 DVD DECK MECHANISM SECTION DVM H1723 151 155 159 170 163 162 177 172 167 166 175 180 137 012 012 A01 A02 012 430 164 173 165 153 156 153A 169A 169B 169C 035 430 430 010 181 A26 ...

Page 15: ...2 9 2 10 MEMO MEMO ...

Page 16: ...2 11 4 SPEAKER SECTION 4 1 FRONT SPEAKER MDS505V A60 ...

Page 17: ...2 12 4 2 PASSIVE SUBWOOFER MDS505W A90 ...

Page 18: ...808 Battery 811 RCA Cable 1 Pin Black 900 Remote Control 824 AM Loop Antenna 801 Owner s Manual 803 Packing Casing 802 Box 825 FM Wire Antenna 804 Bag 2 13 5 PACKING ACCESSORY SECTION ...

Page 19: ...2 14 MEMO ...

Page 20: ...K CIRCUIT DIAGRAM 3 41 6 MAIN MPEG CIRCUIT DIAGRAM 3 43 7 MAIN SERVO CIRCUIT DIAGRAM 3 45 8 MAIN I O CIRCUIT DIAGRAM 3 47 9 VFD CIRCUIT DIAGRAM 3 49 10 MIC USB CIRCUIT DIAGRAM 3 51 11 VOLUME CIRCUIT DIAGRAM 3 53 12 IPOD CIRCUIT DIAGRAM OPTIONAL PART 3 55 13 KARAOKE CIRCUIT DIAGRAM OPTIONAL PART 3 57 CIRCUIT VOLTAGE CHART 3 59 PRINTED CIRCUIT BOARD DIAGRAMS 3 61 1 MAIN P C BOARD 3 61 2 SMPS P C BOA...

Page 21: ...hort Check 3 7 V lines short Replace PC951 PC972 IC901 Check BD901 to Pin impedance Check MAIN or AMP board short Replace PC972 IC902 s components Check around IC901 s components Short Open Low impedance Replace IC901 BD901 NO NO NO NO NO Check the AC line pattern Check fuse F901 Check C963 voltage 5 6 V Check C978 voltage 3 9 V Check IC901 Vcc voltage 10 V 30 V ...

Page 22: ...BLESHOOTING GUIDE YES YES No sound Replace IC961 IC901 or SMPS board Check no power list AC input voltage Check AMP module short Replace PC951 IC901 NO NO Check IC961 Vcc voltage 34 V 43 V Check C955 voltage 25 V or 36 V ...

Page 23: ...k MAIN board Replace LED LD301 LD315 WELCOME Display on VFD ok When you turn the volume knob count is change NO NO NO NO NO NO NO NO PN301 cable connection ok PN301 Pin22 26 signal ok PN301 Pin1 2 3 6 power ok PN301 Pin7 8 9 10 data signal ok IC301 check ok 2 FRONT BOARD YES Check SMPS board Check Main board YES YES Volume LED LD301 LD315 turn on NO NO NO PN301 Pin21 12 V ok Check PN301 Pin11 13 2...

Page 24: ...02 IC602 I2S output signal ok YES YES A NO NO HEADPHONE output Check IC301 Check CN301 and Connection IC301 Pin 1 Pin 7 audio signal ok Front Board CN301 Pin1 3 audio signal ok YES YES NO AUX function Check JK201 IC200 Pin7 8 audio L R ok YES B NO PORTABLE function Check JK301 Check Front Board stage and JK301 IC200 Pin21 22 audio L R ok YES B ...

Page 25: ...C200 Pin26 27 audio signal ok YES YES YES YES YES B NO NO NO NO NO NO TUNER Function Check Tuner TU345 and Antenna connection Check IC200 Check IC500 Check IC602 Check IC500 and X500 Check IC701 Check AMP IC output stage and JK701 JK702 IC200 Pin23 24 audio L R ok IC200 Pin41 I2S output signal ok IC602 Pin4 8 I2S input signal ok IC602 I2S output signal ok IC200 Pin42 43 44 I2S clock ok IC701 audio...

Page 26: ...in2 3 4 video signal ok Check IC201 YES NO IC201 Pin11 12 13 video signal ok Check JK201 CVBS video out Check JK201 YES Check Micom IC101 YES Check IC252 IC252 Pin4 video signal ok NO NO IC252 Pin6 LOW signal IC201 Pin14 video signal ok IC252 Pin3 video signal ok NO NO Check IC201 Check IC500 YES YES ...

Page 27: ...deo signal ok NO NO IC252 Pin6 HIGH signal IC201 Pin14 video signal ok IPOD B D CN201 Pin23 video signal ok MAIN B D IC250 Pin4 ok IPOD B D CN202 Pin10 ok IC252 Pin1 video signal ok NO NO NO NO NO Check IC201 Check IPOD connection or CN201 Check 15p Harness cable and connection Check IPOD Board Check IC250 YES YES YES YES YES ...

Page 28: ...on SLED at inner side Recieve OPEN CLOSE Key Receive CLOSE Key SLED moves to inner position 1 Judge whether have disc and disc type 2 Jump to related disc reading procedure 1 Execute Pressed Key IR Key 2 System operation routine loop NO NO NO NO YES 1 Stop Playback Open Tray 2 Display tray open message LOGO POWER ON 5 SYSTEM OPERATION FLOW YES ...

Page 29: ...from the SMPS TEST Are 3 7 5 6 12 and 28 V 36V DC outputs normal on Main PCBA Switch on the Power PCBA Update FLASH successfully Check the POWER PART Check the regulators or diode 1 Check 27 MHz system clock 2 Check system reset circuit 3 Check FLASH R W enable signal PRD RWR 4 Check FLASH Memory related circuit Replace FLASH 6 TEST DEBUG FLOW ...

Page 30: ...in139 143 145 146 NO NO Check the load OPEN CLOSE switch NO YES YES YES Check the Tray control IO Pin on MT1389SE GH and IC401 NO Normal OPEN_SW CLOSE_SW signal Check the Tray control MOTOR SERVO circuit IC400 NO B A Power On NO Does Tray move inside when it is not at closed position Show LOGO Check AV cable connection to TV set SDRAM works properly MT1389SE GH VIDEO outputs properly Check FFC cab...

Page 31: ... GH and motor driver NO YES YES Check the amp circuit on motor driver NO Proper Focus outputs to motor driver C B Optical Lens has movements for searching Focus Does the SLED move to inner side when it is at outer position NO Check the cable connection with MECHA Do not put in disc and close tray Motor Driver SLD Pin is High SLED and SLED output properly Check cable connection with pick up head Pr...

Page 32: ...389SE GH and connecting to power transistor Q400 Q401 YES Check cable connection between transistor output and pick up head 23p FFC Laser off Check the RF connection between S3053 and MT1389SE GH Check the related circuit on laser power transistor Collector voltage of power transistor is OK Q400 Q401 Check the cable connection between sPindle and main PCB 15p FFC Check the sPindle control amp circ...

Page 33: ... tracking control amp circuit on motor driver NO NO NO YES Proper TRACK signal on MT1389SE GH YES T T output properly YES E D YES Check CD_DVDCT connection between S3053 and MT1389SE GH Check cable connection on pick up head YES YES Proper signals on A B C D of MT1389SE GH Proper CD_DVDCT signal on MT1389SE GH Focus on ok NO Disc Playback NO YES Proper CD_DVDCT signal on MT1389SE GH YES YES Track ...

Page 34: ...ved correct data stream TEST END NO E Normal Audio output when disc playback Check connection between IC500 BCK LRCK ADATA0 ADATA1 ADATA2 Pin157 158 160 161 162 Check AMP IC IC701 702 703 Check the related circuit of PWM IC Normal PWM IC out IC602 ...

Page 35: ...RMS ON SYSTEM TEST AND DEBUGGING 1 SYSTEM 27 MHz CLOCK RESET FLASH R W SIGNAL 2 MT1389SE GH reset is high active 4 1 MT1389SE GH main clock is at 27 MHz X500 1 FIG 1 1 1 FIG 1 2 Power Cord in 2 3 4 2 3 P_CTL RESET_IN DVD_RST ...

Page 36: ...3 17 3 Flash R W enable signal during download Downloading 5 6 2 SDRAM CLOCK 7 1 MT1389SE GH main clock is at 27 MHz X500 FIG 1 3 6 5 FIG 2 1 7 SF_DI SF_DO DCLK 93 MHz Vp p 2 2 Vmax 2 7 V SDCLK ...

Page 37: ...3 18 3 VIDEO PART 1 100 FULL COLOR BAR CVBS_I Y Pb Pr 8 9 10 11 8 10 9 11 ...

Page 38: ...3 19 4 VIDEO PART 2 100 FULL COLOR BAR CVBS COMP_Y COMP_Pb COMP_Pr 12 14 13 15 12 13 14 15 ...

Page 39: ...SIGNAL 1 Tray open close waveform 2 Tray close waveform 3 Tray open waveform 17 16 19 18 FIG 5 3 16 OPENSW CLOSESW OPEN 19 18 17 CLOSE FIG 5 1 OPENSW CLOSESW OPEN CLOSE FIG 5 2 OPENSW CLOSESW OPEN CLOSE 16 19 18 17 16 19 18 17 ...

Page 40: ...3 21 20 22 23 21 6 SLED CONTROL RELATED SIGNAL NO DISC CONDITION FIG 6 1 20 21 22 23 SLD M STBY SL SL ...

Page 41: ...3 22 8 LASER POWER CONTROL RELATED SIGNAL NO DISC CONDITION 7 LENS CONTROL RELATED SIGNAL NO DISC CONDITION 24 26 25 FIG 8 1 27 28 29 28 27 29 FIG 7 1 24 25 26 FOD F F MDI1 CDLD DVDLD ...

Page 42: ...3 23 9 DISC TYPE JUDGEMENT WAVEFORMS 30 32 31 31 This signal can see using special debug program FIG 9 1 DVD 30 31 32 F PU_DET RF FIG 9 2 DVD 30 31 32 F PU_DET RF ...

Page 43: ...3 24 FIG 9 3 CD 33 34 35 F PU_DET RF FIG 9 4 CD 33 34 35 F PU_DET RF 35 34 34 This signal can see using special debug program 33 ...

Page 44: ...3 25 10 FOCUS ON WAVEFORMS 37 39 38 36 36 This signal can see using special debug program FIG 10 1 DVD 36 37 38 39 PU_DET FOD F F FIG 10 2 CD 36 37 38 39 PU_DET FOD F F ...

Page 45: ...3 26 40 42 41 11 SPINDLE CONTROL WAVEFORMS NO DISC CONDITION FIG 11 1 42 41 40 SPinD SP SP ...

Page 46: ...44 12 TRACKING CONTROL RELATED SIGNAL System checking 43 43 PU_DET TRO 43 PU_DET TRO 45 44 46 45 44 T T FIG 12 1 DVD FIG 12 2 CD 46 T PU_DET TRO T T T PU_DET TRO 43 This signal can see using special debug program ...

Page 47: ...3 28 MEMO ...

Page 48: ...6P DECK MECHANISM SMPS PCB IPOD PCB FRONT PCB 15P 10P 36P 9P 8P MIC USB PCB 8P JOG PCB CN400 8P 7P KARAOKE PCB 2P 15P DC FAN 15P 23P 2P 5P 5P 4P 2P CN401 PN102 CN301 P1001 PN301 CN302 PN304 CN202 P8502 P7708 P8501 CN952 CN951 PN201 CN200 CN102 PN101 CN101 6P CN501 CN502 WIRING DIAGRAM ...

Page 49: ...ATA MIC MIC L R S4308 OP AMP Component Composite THS7314 VIDIO FUNC Y G Pb B Pr R IPOD VIDEO CVBS PR Y PB R G B UART DSP_BSY DSP_IBO PWM DSP_CLK PWM DSP_DATA 9 8304 MHz PWM_RST DATA CLK AMP_SD AMP_OTW AMP_PDN FAN FAN_CTRL FAN_AD CP2 0 IPOD DATA RST CLK NLASB 3157 DFT2G VIDEO SW HA12237F Cassette Deck ASP DECK S W Deck SOL MOTOR PLAY REC L R TAPE REC_BIAS REC PB_MUTE PS9850 DSP PWM Modulat USB HALL...

Page 50: ...IT USED THIS WAY IMPLEMENTATION OF THE LATEST SAFETY AND PERFORMANCE IMPROVEMENT CHANGES INTO THE SET IS NOT DELAYED UNTIL THE NEW SERVICE LITERATURE IS PRINTED NOTE 1 Shaded parts are critical for safety Replace only with specified part number 2 Voltages are DC measured with a digital voltmeter during Play mode A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T Warning Parts that ...

Page 51: ...3 35 3 36 2 MAIN MICOM CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MAIN 001 MICOM EBY60749301 REV 7 1 ...

Page 52: ...3 37 3 38 3 MAIN PWM CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MAIN 002 PWM EBY60749301 REV 7 1 ...

Page 53: ...3 39 3 40 4 MAIN AMP CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MAIN 003 AMP EBY60749301 REV 7 1 ...

Page 54: ...3 41 3 42 5 MAIN DECK CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MAIN 004 DECK EBY60749301 REV 7 1 ...

Page 55: ...3 43 3 44 6 MAIN MPEG CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MAIN 005 MPEG EBY60749301 REV 7 1 ...

Page 56: ...3 45 3 46 7 MAIN SERVO CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MAIN 006 SERVO EBY60749301 REV 7 1 ...

Page 57: ...3 47 3 48 8 MAIN I O CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MAIN 007 I O EBY60749301 REV 7 1 ...

Page 58: ...3 49 3 50 9 VFD CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MD505 MDD305 VFD FRONT EBY60729301 REV 6 2 ...

Page 59: ...3 51 3 52 10 MIC USB CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MDT505 MDD305 MCT565 MIC USB EBY60729401 REV 6 2 ...

Page 60: ...3 53 3 54 11 VOLUME CIRCUIT DIAGRAM A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MDT505 MDD305 MAIN VR JOG VOL EBY60729501 REV 2 2 ...

Page 61: ...3 55 3 56 12 IPOD CIRCUIT DIAGRAM OPTIONAL PART A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MDT505 IPOD EBY60729701 REV 5 2 ...

Page 62: ...3 57 3 58 13 KARAOKE CIRCUIT DIAGRAM OPTIONAL PART A 1 2 3 4 5 6 7 8 9 10 11 12 B C D E F G H I J K L M N O P Q R S T MDS715 MDT505 MDD305 NO KEY EBY60729601 REV 4 1 ...

Page 63: ...ec V 100V 10 240V 50Hz 10 Voltage V Voltage V 1 BD901 600 127 3 373 3 2 C901 150 uF 450 127 3 373 3 3 C902 150 uF 450 127 3 373 3 4 C909 4 7 uF 50 19 6 19 6 5 C910 22 uF 50 22 0 22 0 6 C913 22 uF 50 22 2 22 2 7 C952 470 uF 50 43 1 43 1 8 C955 470 uF 50 43 1 43 1 9 C961 470 uF 50 43 1 43 1 10 C963 1000 uF 10 7 32 7 32 11 C965 47 uF 50 38 6 38 6 12 C966 1000 uF 25 12 6 12 6 13 C967 100 uF 10 4 96 4 ...

Page 64: ...3 61 3 62 PRINTED CIRCUIT BOARD DIAGRAMS 1 MAIN P C BOARD TOP VIEW ...

Page 65: ...3 63 3 64 MAIN P C BOARD BOTTOM VIEW ...

Page 66: ...3 65 3 66 2 SMPS P C BOARD NOTE Warning Parts that are critical with respect to risk of fire or electrical shock MDS715 EAX35194121 REV 4 2 2010 06 11 ...

Page 67: ...3 FRONT VFD USB MIC VOLUME P C BOARD 3 67 3 68 ...

Page 68: ...3 69 3 70 5 KARAOKE P C BOARD OPTIONAL PART 4 IPOD P C BOARD OPTIONAL PART TOP VIEW BOTTOM VIEW ...

Page 69: ...3 71 3 72 MEMO MEMO ...

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