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LG RAD225B, Service Manual, Page: 20 / 45

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LG RAD225B Service Manual Download Page 20

3-7

6. PWM MODULATION CHECK

   PWM MODULATION PART CHECK

Check

CN105 Pin10 3.7 VA.

• Check IC602(PS9850) VDD 3.3 V
  (Pin16,24,29,32,35,40,48,61,64) 
• Check VDD Core 1.2 V (Pin1,21,43,57,59,60)
• Check X602(19.2 MHz)

NO

Refer to SMPS troubleshooting.

Check

X602(19.2 MHz)

operation.

NO

Replace 

X602(19.2 MHz).

Check X602

(19.2 MHz).

OK

YES

NO

Check

 IC602(PS9850)

Pin51 CLK input. 

Check

IC102(LC87Fxx)

  Pin41:PWM RESET

Pin45:PWM SDA 

Pin46:PWM SCL

output.

NO

Replace R636,R637,R638.

Check line

resistor output

RST: R636 / SCL: R637 /

SDA: R638.

NO

YES

YES

YES

YES

YES

YES

OK

YES

Summary of Contents for RAD225B

Page 1: ...ICE MANUAL MODEL RAD225B RAS225B CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL MODEL RAD225B RAS225B SERVICE MANUAL P NO AFN73972629 MARCH 2010 Website http biz lgservice com Internal Use Only ...

Page 2: ... 1 CABINET AND MAIN FRAME SECTION 2 1 MECHANISM DECK SECTION CDM 345 2 3 SPEAKER SECTION 2 5 PACKING ACCESSORY SECTION 2 6 SECTION 3 ELECTRICAL PART TROUBLESHOOTING GUIDE 3 1 DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING 3 14 WIRING DIAGRAM 3 18 BLOCK DIAGRAMS 3 19 CIRCUIT DIAGRAMS 3 21 CIRCUIT VOLTAGE CHART 3 33 PRINTED CIRCUIT DIARGAMS 3 35 SECTION 4 REPLACEMENT PARTS LIST 4 1 ...

Page 3: ...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 therefo...

Page 4: ...re 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 preven...

Page 5: ...harges 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 comparabl...

Page 6: ...5s FLD OP 0 Move to appropriate position and make changes with Rmc skip mode play key Press STOP key FLD write ok Remote control Front STOP push same timing FLD E2P CLR Completed NAME OPT 0 OPT 1 OPT 2 OPT 3 OPT 4 OPT 5 OPT 6 OPT 7 OPT 8 OPT 9 DETECT NEW EEPROM OPTION EDIT SCREEN HEX 09 00 00 00 00 68 80 05 40 00 ...

Page 7: ...e security software then download the file to your set 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 READ FIRMWARE WRITE 00 100 UPDATED POWER OFF AUTOMATICALLY When completed remove u...

Page 8: ...ity software then download the file to your set 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 READ FIRMWARE FINISH UPDATED POWER OFF AUTOMATICALLY When completed remove usb device ...

Page 9: ...ange 87 5 108 0 MHz or 87 50 108 00 MHz FM Intermediate Frequency 128 kHz AM Tuning Range 522 1 620 kHz 520 1 710 kHz or 522 1 710 kHz AM Intermediate Frequency 45 kHz AMPLIFIER Output Power Front 110 W 110 W 4 Ω at 1 kHz THD 10 CD Frequency Response 40 Hz 20 000 Hz Signal to noise ratio 75 dB Dynamic range 80 dB SPEAKERS Front Speaker Type 2 Way 2 Speaker Impedance 4 Ω Rated Input Power 110 W Max...

Page 10: ...76 265 259 A26 460 460 A46 300 460 460 273 274 460 279 460 460 262 460 257 CABLE2 260R A43 A44 A42 460 SECTION 2 EXPLODED VIEWS CABINET AND MAIN FRAME SECTION RAD225B 2 1 2 2 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 11: ...2 3 2 4 MECHANISM DECK SECTION CDM 345 018 439 014 013 017 019 026 015 431 020 A01 A02 001 002 003 016 036 010 012 012A 012A 012 432 432 037 A03 A26 ...

Page 12: ...2 5 A60 SPEAKER SECTION FRONT SPEAKER RAS225B ...

Page 13: ...2 6 PACKING ACCESSORY SECTION 825 FM Wire Antenna 900 Remote Control 803 Packing 803 Packing 808 Battery 802 Box 801 Instruction Ass y 804 Bag 824 AM Loop Antenna ...

Page 14: ...NO Is TH902 normal Replace TH902 YES NO Is Vcc 10 V 18 V supplied to IC901 Pin7 Is D904 normal YES NO Check or replace D904 Is there about 2 5 V at IC903 Pin1 Replace IC903 YES NO Is D923 normal Replace D923 YES NO Is D921 normal Replace D921 YES NO Is D924 normal Replace D924 YES NO Is D925 normal Replace D925 YES NO Is D922 normal Replace D922 YES NO Power line of I O PCB is short NO ...

Page 15: ...ES NO Is Vcc 10 V 18 V supplied to IC902 Pin7 Is D905 normal YES NO Check or replace D905 Check the power CTL H signal from µ COM Check PC902 Is Q902 normal Replace Q902 Check or replace Q910 YES NO Is D929 normal Replace D929 YES NO Is there about 2 5 V at IC904 Pin1 Replace IC904 YES NO Is Q910 base H Power line of main PCB is short NO NO ...

Page 16: ...ES YES NO Is the 13 V Supplied to Q953 base Check the power CTL H signal from µ COM YES NO Check or replace Q953 No 5 V Is Vcc 6 V supplied to IC951 Pin1 Check or replace D923 YES YES NO Check IC951 Pin4 H Check the power CTL H signal from µ COM YES NO Check or replace IC951 ...

Page 17: ...Refer to SMPS troubleshooting NO NO Check voltage of IC102 LC87Fxxx Pin59 36 Check the periphery of IC105 KIA7027 NO Replace IC105 KIA7027 NO Check if IC105 voltage is over 3 5 V OK OK YES YES YES YES YES No VFD Is D925 normal Check or replace D925 YES YES NO Is ZD951 normal Is Q951 normal Check or replace ZD951 Check or replace Q951 YES YES NO NO Check or replace VFD ...

Page 18: ...th end voltage of D105 102 Check if IC102_Pin49 and IC102_Pin36 59 are 3 5 V YES Check D102 105 Replace D102 105 NO NO X101 32 768kHz X102 9 8304MHz Check the operation OK YES YES YES YES YES OK 4 IC101 S24CS16A01 CHECK CHECK IC102 PIN47 48 Refer to µ COM troubleshooting NO Pin47 DATA Pin48 CLK Replace µ COM NO YES Check µ COM voltage 3 5 V Check µ COM YES OK OK YES YES NO ...

Page 19: ... Pin11 3 7 VA YES OK NO Check CN304 connection YES Check each Pin voltage YES Check IC501 ET6315 voltage Pin30 VKK 26 V Pin13 43 5 V YES Check IC102 IC501 data communication 3Pin 9Pin STB 2Pin 7Pin DATA 4Pin 8Pin CLK FLD light on OK NO If voltage is Not 3 7 VA check input and output of D501 YES Check IC501 YES NO Replace IC501 NO Check input data IC102 Pin2 3 4 YES OK Check IC102 YES NO Replace IC...

Page 20: ...3 57 59 60 Check X602 19 2 MHz NO Refer to SMPS troubleshooting Check X602 19 2 MHz operation NO Replace X602 19 2 MHz Check X602 19 2 MHz OK YES NO Check IC602 PS9850 Pin51 CLK input Check IC102 LC87Fxx Pin41 PWM RESET Pin45 PWM SDA Pin46 PWM SCL output NO Replace R636 R637 R638 Check line resistor output RST R636 SCL R637 SDA R638 NO YES YES YES YES YES YES OK YES ...

Page 21: ...CD troubleshooting Check CD Assy communication Pin4 5 6 OK NO NO Check each line resistor output Check IC602 PS9850 data input Check PWM modulator output FL Pin31 30 FR Pin28 27 other output check NO Replace IC602 PS9850 Check IC602 PS9850 NO OK YES YES YES YES YES YES ...

Page 22: ... V YES YES Check IC700 IC701 Pin30 31 38 39 42 43 50 51 input voltage YES Check each line resistor output voltage NO Check each IC603 Pin64 12 V input Check IC701 IC702 Pin28 29 36 37 43 44 52 53 Replace the coil NO Check output line coil Check PWM Modulator input IC700 Pin4 5 10 11 IC701 Pin4 5 YES YES YES YES OK ...

Page 23: ...put YES YES Check IC401 CS5346 Pin9 data output YES Check IC401 Pin46 3 3 V Pin5 5 V Check CN105 Pin7 5 V Pin9 10 3 3 V NO NO Check IC801 MLC9800 data input YES YES Check IC401 Pin6 High Pin5 5 V Pin46 3 3 V Check IC401 Pin44 MCLK 43 LRCK 42 SLCK 41 SDOUT NO NO Replace IC401 IC501 MLC9800 data output OK YES ...

Page 24: ...NCTION CHECK TUNER FUNCTION CHECK Check tuner module voltage Pin4 3 3 V NO Check tuner module TU100 operation YES YES Check IC102 Pin21 22 23 24 25 data in output Check tuner module data NO YES Refer to function check ...

Page 25: ...signal of IC302 Pin34 35 36 NO YES Check the signal 16 0344 MHz of IC302 Pin31 NO YES Check IC801 input output and control line NO YES YES Check loading motor NO OPU driving Focus and tracking is ok NO Focus tracking sled signal is ok NO Check IC301 Motor drive IC NO Is the PD CN301 Pin12 about 180mV YES Check Vcc of IC302 Check Cristal X301 NO Replace Cristal X301 Replace IC801 Check IC301 YES 1 ...

Page 26: ...YES Check usb_D D R501 R502 YES Plug in usb device Check CN401 NO NO YES Display READ YES Display NO FILE YES Check usb jack JK501 NO Replace IC801 NO Check IC801 Pin116 117 Check usb audio file in usb device MP3 WMA file is playable YES 2 USB FUNCTION ...

Page 27: ...3 14 DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING 1 FLASH SDRAM 1 2 3 4 CLK DATA ADDRESS RESET 2 SERVO 5 ...

Page 28: ...3 15 6 7 8 9 FE TE FOD RF 3 AUDIO PATH 10 11 12 BCK LRCK DATA ...

Page 29: ...3 16 13 14 15 BCK LRCK DATA 16 17 18 MCK BCK LRCK DATA 19 ...

Page 30: ...3 17 20 21 22 USB_5V D D ...

Page 31: ...ING DIAGRAM 16PIN 5PIN SPK TERMINAL TUNER MODULE CD MD CDM 340 MAIN CD PCB 16PIN USB FRONT PCB SMPS PCB 6PIN CN501 CN502 CN304 CN401 CN301 FFC FFC 7PIN AUX JACK 6PIN 15PIN CN105 CN302 CN303 CN901 CN902 3 CN104 ...

Page 32: ...0 6 s s 7s 63 1 s 2 s TDO SLDO SPDO FDO 12MHZ 16 93MHZ tsj _WW tjzGsvnpjG 5 6 7 0 87 POWER I F 3 7V 12V mkGkyp lyG l ZX h DAT CLK RST CE INT RST WEN CE A 0 18 DB 0 15 OP CL OP CL LI MIT CD BCK LRCK DOUTA DAC MCLK P SENSE tpjvtG sj_ m t h PWM PS9850 DO STB CLK ADC CLK ADC DAT ADC RST ADC DATA uly R L R L I2S CLK DAC BCK LRCK MCLK DAC DATA PWM RST PWM CLK PWM DAT PDN SD OTW FL FL FR FR D P CTRL R L ...

Page 33: ...ck Main SMPS IC Block T R A N S Snubber Block Photo coupler Photo coupler Photo coupler FL FL On Off Vkk On Off 5V 5V LDO 12V 12V Regulation Block 3 7VA P CTL On Off On Off AMP SMPS IC With FET Block F U S E Y Cap Y Cap T R A N S SMPS 5 6VA CD P CTL CN901 CN902 3 Feedback Feedback ...

Page 34: ...ODIFIED OR ALTERED WITHOUT PERMISSION FROM THE LG CORPORATION ALL COMPONENTS SHOULD BE REPLACED ONLY WITH TYPES IDENTICAL 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 IMPROVEMENT CHANGES INTO THE SET IS NOT...

Page 35: ...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 RAT375 µCOM AD EBY60808601 Rev 4 1 2 MAIN MICOM CIRCUIT DIAGRAM 3 23 3 24 ...

Page 36: ...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 RAT375 CD DSP SERVO EBY60808601 Rev 4 1 3 MAIN CD DSP SERVO CIRCUIT DIAGRAM 3 25 3 26 ...

Page 37: ...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 RAT375 PWM AMP EBY60808601 Rev 4 1 3 27 3 28 4 MAIN PWM AMP CIRCUIT DIAGRAM ...

Page 38: ...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 FRONT RAT375 EBY56948501 Rev 1 13 5 FRONT CIRCUIT DIAGRAM 3 29 3 30 ...

Page 39: ...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 USB RAT375 Rev 1 13 6 USB CIRCUIT DIAGRAMS 3 31 3 32 ...

Page 40: ...7 28 43 VDD 4 5 5 5 3 42 1 08 3 42 1 08 Loca No Value Capacitor uF Voltage Spec EE Mode Playback Rec Voltage Positive Negative Gap Margin Positive Negative Gap Margin Positive Negative Gap Margin MAIN BOARD C118 1000uF 6 3V 3 39V 0V 3 39V 2 91V 3 38V 0V 3 38V 2 92V 3 39V 0V 3 39V 2 91V C302 100uF 16V 3 26V 0 01V 3 25V 12 75V 3 25 0 03 3 22V 12 78V 3 26 0 03 3 23V 12 77V C304 100uF 16V 1 63V 0 01V ...

Page 41: ...PRINTED CIRCUIT BOARD DIARGAMS 1 MAIN P C BOARD DIAGRAM TOP VIEW 3 35 3 36 ...

Page 42: ...MAIN P C BOARD DIAGRAM BOTTOM VIEW 3 37 3 38 ...

Page 43: ...2 SMPS P C BOARD DIAGRAM 3 39 3 40 Warning Parts that are shaded are critical with respect to risk of fire or electrical shock ...

Page 44: ...3 FRONT USB P C BOARD DIAGRAM 3 41 3 42 ...

Page 45: ...3 43 3 44 MEMO MEMO ...

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