LG OM7550 Service Manual Download

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3-3

ONE POINT REPAIR GUIDE

2. NO AMP POWER

If the unit doesn’t work by no ±PVDD problem, repair the set according to the following guide.

2-1. FUSE/ FET

2-1-1. Solution

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

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

1) Check if the fuse F911 is open or short-circuit.
2) Check the Drain-Source or Drain-Gate, Gate-Source Resistance of Q905~Q906 with a digital multimeter.



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).

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

< F911 >

If F911 is not short-circuit,

replace it with a same speci

cations one.

< Q905~Q906 >

If Q905~Q906 is short-circuit,

replace it with a new one.

Summary of Contents for OM7550

Page 1: ... SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL Internal Use Only Website http biz lgservice com Mini Hi Fi AUDIO MODEL OM7550 MODEL OM7550 P NO AFN77277076 SEPTEMBER 2015 ...

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

Page 3: ...ONTENTS 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 1 AUDIO PROGRAM 1 8 2 CD PROGRAM 1 9 3 EQ PROGRAM 1 10 SPECIFICATIONS 1 11 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: ...ller 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...

Page 8: ...tus too This is an example Front STOP Remote control push same timing during 5s FLD OP00 Move to appropriate position And make changes with RMC REPEAT key Press STOP Key VFD WRITE OK Front STOP Remote control push same timing during 5s VFD E2P CLR Completed 1 7 SERVICE INFORMATION FOR EEPROM dM ...

Page 9: ...ile 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 1 Fast Format USB device 2 Copy Firmware file to USB device NO USB Insert USB device at USB function SEARCH MICOM ...

Page 10: ... 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 1 Fast Format USB device 2 Copy Firmware file to USB device NO USB Insert USB device at USB function...

Page 11: ... 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 1 Fast Format USB device 2 Copy Firmware file to USB device NO USB Insert USB device at USB func...

Page 12: ... 41 F to 95 F Operating humidity 60 Bus Power Supply 5 V 500 mA INPUTS OUTPUTS AUX IN OUT 2 0 Vrms 1 kHz 0 dB 600 Ω RCA jack L R PORT IN 1 2 Vrms 3 5 Ø jack MIC 20 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 Total output 1000 W FRONT 500 W x 1 6 Ω at 150 Hz Subwoofer 500 W x 1 6 Ω ...

Page 13: ...1 12 ...

Page 14: ... CHASSIS CONTENTS DISASSEMBLY INSTRUCTIONS 2 2 1 HOW TO DISASSEMBLE THE SIDE COVER LEFT RIGHT 2 2 EXPLODED VIEWS 2 5 1 CABINET AND MAIN FRAME SECTION 2 5 2 DECK MECHANISM SECTION DM19 2 7 3 PACKING ACCESSORY SECTION 2 9 2 1 ...

Page 15: ...STRUCTIONS Figure 1 Figure 2 Step 1 Insert JIG into groove and then raise Cover_Side with a lever JIG to outside direction Step 2 Tap Push silde Cover_Side to back direction 1 HOW TO DISASSEMBLE THE SIDE COVER LEFT RIGHT ...

Page 16: ...2 3 Figure 3 Step 3 Seperate Cover_Side to out direction ...

Page 17: ...2 4 ...

Page 18: ... N L K P K J J M R MAIN SMPS TOP VFD FRONT B T 468 A52 255 256 257 468 468 468 263 264 265 266 267 268 270 A46 468 468 443 443 285 286 284 283 282 282 A47 443 443 443 260 262 261 A41 250 251 443 A44 254 A43 A42 443 A49 A50 275 277 276 279 512 278 252 468 512 512 512 512 443 518 518 CABLE2 CABLE3 281 512 CABLE5 ...

Page 19: ...1439 A001 1002 1005 1001 1049 1437 1437 1024 1024 1024 1024 1003 1011 1437 1004 1026 1030 1043 1045 A005 A006 1016 1013 1015 1020 1439 1018 1019 1012 1006 2 DECK MECHANISM SECTION DM19AA 2 8 2 7 ...

Page 20: ...3 PACKING ACCESSORY SECTION 2 9 825 FM Antenna 900 Remote Control 803 Packing 803 Packing 808 Batteries 801 Owner s manual 803 Packing 802 Box 803 Packing 804 Bag 300 Power Cord ...

Page 21: ...2 10 ...

Page 22: ...NG DIAGRAM 3 41 BLOCK DIAGRAMS 3 43 1 SYSTEM BLOCK DIAGRAM 3 43 2 POWER BLOCK DIAGRAM 3 45 CIRCUIT DIAGRAMS 3 47 1 SMPS_POWER 1 CIRCUIT DIAGRAM 3 47 2 SMPS_POWER 2 CIRCUIT DIAGRAM 3 49 3 MAIN_CD DSP CIRCUIT DIAGRAM 3 51 4 MAIN_ADC PWM CIRCUIT DIAGRAM 3 53 5 MAIN_RF SERVO CIRCUIT DIAGRAM 3 55 6 MAIN_AMP CIRCUIT DIAGRAM 3 57 7 MAIN_AUX OUT VFD PWR CIRCUIT DIAGRAM 3 59 8 FRONT CIRCUIT DIAGRAM 3 61 9 ...

Page 23: ...bleshoot 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 multimeter 3 Check if the NTC thermistor TH900 TH902 is normal or open 1 1 3 Service hint Any picture Remark F901 If F901 is not short circuit replace it with a same specifications one TH900 TH901 If TH900 TH901 is open replace it with a new on...

Page 24: ... Check if the fuse F911 is open or short circuit 2 Check the Drain Source or Drain Gate Gate Source Resistance of Q905 Q906 with a digital multimeter 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 2 1 3 Service hint Any picture Remark F911 If F911 is not short circuit replace it with a same specifications one Q905 ...

Page 25: ...o 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 3 1 3 Service hint Any picture Remark MAIN board top view MAI...

Page 26: ...ut from SMPS to VFD via the MAIN board 2 Check if the IC501 outputs VFD_CLK VFD_DO and VFD_STB to the FRONT board 3 Check if the VFD grid current amplifier circuit on the FRONT board Check the drive signal to the transistor s base If the control signals from VFD DGND VDD isn t output replace VFD with a new one 4 1 3 Service hint Any picture Remark R327 TP304 Q301 Emitter about 30 Vp p VFD schemati...

Page 27: ... Please check if this system is on bass blast mode C RL and RR make sound only on bass blast mode 2 Check the IC700 IC701 IC705 on your eyes 3 Check the audio signal output check pin13 of IC700 IC701 IC705 First Check the PWM Data input pin3 of IC700 IC701 IC705 4 If the audio signal output has no output try to change IC which has no output 5 Lastly check Speaker Terminal CN701 CN702 5 1 3 Service...

Page 28: ...n is detected Main reasons are like below When some of AMP FETs dead 6 1 3 Service hint Any picture Remark Notice for FET service In case of RF6775 Metal case FET Drain has electric potential So be careful when you deal with it You can see FET after removing heatsink Notice for Service Before repair Main Assy you need to discharge SMPS After then open the connector You should try to change both of...

Page 29: ...upply voltage and signal Check AMP IC Poor supply voltage Check SMPS Assy Poor signal Check PWM IC 2 Check CSD of FET driver IC IRS2092 CSD has about 5 V on normal state When AMP has problem CSD is LOW state or keep change LOW to HIGH 7 1 3 Service hint Any picture Remark MAIN board top view MAIN board top view MAIN AMP circuit CN110 CN110 pin1 2 66 V pin1 2 66 V pin3 4 PGND pin3 4 PGND pin5 6 66 ...

Page 30: ...05 pin3 on MAIN board If IC505 pin3 about 4 9 V D500 Input 5 6 VA doesn t come out check 5 6 VA from SMPS board 2 If IC505 pin3 about 4 9 V is normal check the PWR_CTRL IC505 pin2 is high about 3 3 V If PWR_CTRL isn t high check pin B2 of IC501 R524 R522 3 If PWR_CTRL is high check R524 and if there s no defective component then replace IC505 4 If 3 3 V VCC33 is normal check 1 2 V output pin2 volt...

Page 31: ...d 8 2 2 How to troubleshoot Countermeasure 1 If 3 3 V 1 2 V is normal check Reset High of IC501 pinT12 on MAIN board If MAIN_RESET isn t high check MICOM IC101 pin40 2 If MAIN_RESET is high check the soldering status of 24 MHz crystal X500 3 If the crystal X500 doesn t oscillate check R508 R5C5 C502 C503 around crystal X500 If there s no defective component then replace X500 8 2 3 Service hint Any...

Page 32: ...leshoot Countermeasure 1 If the crystal X500 does oscillate check Serial Flash IC503 on MAIN board Check pin8 VCC pin6 CLK pin1 CS pin2 DO pin5 DI of below waveform 2 If pin8 6 1 2 5 doesn t come out check damping resistor R535 R536 R534 and pull up resistor R564 R563 of IC503 If damping resistor of IC503 is OK then replace IC503 it need to download program 3 After change IC503 if It is still not ...

Page 33: ...2 on MAIN board 8 4 2 How to troubleshoot Countermeasure 1 Check below waveform soldering status of SDRAM IC502 on MAIN board If pin17 CAS pin18 RAS pin19 CS pin38 CLK pin29 address pin2 DQ doesn t come out check damping resistor R568 R570 R544 R547 2 If resistor is OK then replace IC502 SDRAM 3 After change IC502 if It is still not below waveform Check IC501 DSP IC 8 4 3 Service hint Any picture ...

Page 34: ...DSP IC501 8 5 1 Solution Please check and replace IC501 on MAIN board 8 5 2 How to troubleshoot Countermeasure 1 After check them by Previous pages about NO Booting if the set is still no booting Check soldering status of IC501 2 If below bootstrap waveform doesn t come out then replace IC501 DSP IC 8 5 3 Service hint Any picture Remark R594 PGPB12 Yellow R598 PAD19 Green R597 PAD20 Pink Bootstrap...

Page 35: ...m pin16 of IC401 If no signal check 3 3 V RF and X400 2 Check the SP SP from IC400 to CN401 for driving SPINDLE motor It is about 3 6 Vp p If no signal check 1 8 V and DVCC 5 V for IC400 3 Check if the FFC cable is solidly connected between CN401 and MD 4 Check the MD If the spindle motor is short circuit or has any trouble it can not rotate CD discs Please check the function after changing anothe...

Page 36: ...01 If no signal check 3 3 V RF and X400 2 Check the SLED SLED from IC400 to CN401 for driving SPINDLE motor It is about 2 9 Vp p If no signal check 1 8 V and 5 V for IC401 3 Check if the FFC cable is solidly connected between CN401 and MD 4 Check the MD If the sled motor is sort circuit or has any trouble it can not move the pickup module Please check the function after changing another MD 9 2 3 S...

Page 37: ...AD from IC400 to CN401 for driving the tray open close motor It is about 3 85 Vp p If no signal check 5 V to IC401 If it has any trouble replace it with a new one 3 Check if the FFC cable is solidly connected between CN401 and MD 4 Check the MD If the tray motor is short circuit or has any trouble it can not open or close the tray Please check the function after changing another MD 9 3 3 Service h...

Page 38: ...f a track on CD disc 1 Check the TRD signal from pin14 of IC401 If no signal check 3 3 V RF and X400 2 Check TR TR from IC400 to CN400 for driving the tracking actuator If no signal check 1 8 V and 5 V for IC400 3 Check if the FFC cable is solidly connected between CN400 and MD 4 Check the MD If the pickup module has any trouble it can not move the laser beam on the left or right side Please check...

Page 39: ... the surface of a CD disc 1 Check the FDO signal from pin13 of IC401 If no signal check 3 3 V RF and X400 2 Check F F from IC400 to CN400 for driving the focusing actuator If no signal check 1 8 V and 5 V for IC400 3 Check if the FFC cable is solidly connected between CN400 and MD 4 Check the MD If the pickup module has any trouble it can not move the laser beam on the top or bottom side Please ch...

Page 40: ...P AMP AZ4580 FET IRF6775 X 2 MLC3730 Main DSP 3 3V_CD VCC1 2 USB1 USB2 IC201 ADC CS5346 PRE AMP S4308 DAC PCM5101 PS9860 PWM DRM_WEN CAS RAS SEL CLK CKE AMP_OSC ADC_DATA MCS_BCK LRCK MCLK FRONT SE SW SE IR_IN_FL FL_OUT_P N SW1_OUT_P N M00_15 A00_16 SF_DI DO SF_CS SCK 500 W MOT_MUTE CLOSE OPEN D2S IR_IN_SW PWM_LRCK BCK DATA DSP_O_DATA AUX_DATA EXP_DATA MCS_BCK LRCK MCLK C CD_RW MCLK LRCK BCK CD_DAT...

Page 41: ...l flow from IC501 to IC202 If there is any trouble check the power for each IC The power is normal but if the signal waveform to the IC is distorted or no signal replace it with a new one 5 Check if the digital audio AMP block is okay If AMP is damaged replace it with a new one 10 2 3 Service hint Any picture Remark AUX IC501 MLC3730 IC202 PS9860 PWM MCS_BCK MCS_LRCK IC201 CS5346 ADC MIC_DATA MCS_...

Page 42: ...K are entered from IC501 to IC201 5 Check if ADC_DATA is entered from IC201 to IC501 If no signal check 5 V 3 3 V ADC for IC201 If is NG replace it a new one 6 Check the following I2S signal flow from IC501 to IC202 If there is any trouble check the power for each IC The power is normal but if the signal waveform to the IC is distorted or no signal replace it with a new one 7 Check if the digital ...

Page 43: ...or IC201 If is NG replace it a new one 4 Check the following I2S audio signal flow from IC501 to IC202 If there is any trouble check the power for each IC The power is normal but if the signal waveform to the IC is distorted or no signal replace it with a new one 5 Check if the digital audio AMP block is okay Refer to Digital Audio AMP guide If AMP is damaged replace it with a new one 10 4 3 Servi...

Page 44: ... a new one 4 Check the following I2S signal flow from IC206 to IC501 If there is any trouble check the power for each IC If the signals are abnormal replace it a new one 5 Check if the digital audio AMP block is okay Refer to Digital Audio AMP guide If AMP is damaged replace it with a new one 10 5 3 Service hint Any picture Remark MLC3730 Main DSP 3 3V_CD VCC1 2 USB1 USB2 IC201 ADC CS5346 PRE AMP ...

Page 45: ... MIC_O_DATA is entered from IC501 to IC600 If no signal check VCC12 1 2 V for IC501 If it is abnormal change replace it a new one 4 Check the following I2S signal flow from IC501 to IC600 If there is any trouble check the power for each IC If the signals are abnormal replace it a new one 5 Check if the digital audio AMP block is okay Refer to Digital Audio AMP guide If AMP is damaged replace it wi...

Page 46: ... F901 same fuse Check or replace D965 Is D960 D961 normal Replace BD901 Check P_CTL from μ com Check and replace IC951 Or check line of MAIN PCB is short or not Check or replace D960 D961 NO NO NO NO NO Is the F901 normal Is the VCC 12 VA supplied to IC951 pin1 Is the VCC 11 V 25 V supplied to IC901 pin4 Is BD901 normal Is there H signal at IC951 pin4 ...

Page 47: ... not Check or replace Q951 Is the VCC 7 VA supplied to IC953 pin2 Is there H signal at Q953 Base NO NO NO Is the D959 normal YES YES YES No output AMP gate line Check or replace R952 Check or replace D952 D959 Check and replace IC952 Or check line of MAIN PCB is short or not Is the VCC 13 VA supplied to IC952 pin1 to pin3 NO NO Is the R952 normal YES YES ...

Page 48: ...910 Check or replace IC902 and Check Q905 Q906 gate pin1 Components Resistors Diodes Is Q905 Q906 OK Replace Q905 Q906 Check or replace D954 D955 Check line of MAIN PCB is short or not Is the C904 Voltage about 390 V Is F911 normal Is the PFC P CTL OK Is the AMP P CTL OK Is the VCC 12 V supplied to IC904 pin16 Is the VCC 12 V supplied to IC902 pin8 NO YES NO NO NO NO YES NO YES YES YES YES NO NO ...

Page 49: ...le Check MAIN board Check SMPS board Replace DIG3E11 FL VKK voltage OK Check MAIN board HELLO Display on FLD OK When turn the volume count is change NO NO NO NO NO NO NO CN605 cable connection OK Check CN605 pin5 6 I2C data OK CN605 pin8 9 10 data signal OK CN605 pin7 14 15 16 power OK YES YES YES YES YES YES ...

Page 50: ...Check loading motor Check IC501 OPU driving Focusing Tracking OK Check OPU Pick up module Is motor impedance about 12 Ω IC401 pin34 35 36 I2S output signal OK Can disc insert IC501 pin N1 N2 N4 I2S input signal OK Disc reading OK NO NO NO NO NO NO NO NO NO IC401 RF Servo signal OK Focusing Tracking Sled signal OK LOAD OK YES YES YES YES YES NO YES YES YES A 3 NO AUDIO CHECK ...

Page 51: ...1 USB Power 5 VU OK YES A A When insert USB IC501 pin U7 U8 A7 A8 USB_D signal OK NO YES YES YES YES AUX Check audio cable Replace IC201 Check IC501 NO NO NO IC201 pin23 24 AUX input signal OK IC201 pin41 ADC MIC_data output signal OK IC201 pin42 43 44 I2S input signal OK ...

Page 52: ...IN input signal OK IC201 pin41 ADC MIC_data output signal OK IC201 pin42 43 44 I2S input signal OK TUNER Check IC501 Replace IC201 Check 3 3 V of TU500 IC201 pin42 43 44 I2S input signal OK IC201 pin41 ADC data output signal OK NO NO NO TU500 TUNER_L R output signal OK YES A IC201 pin26 27 TUNER_L R input signal OK NO YES YES YES ...

Page 53: ...32 ELECTRICAL TROUBLESHOOTING GUIDE B A YES YES YES YES Check IC501 Replace IC202 Check IC501 NO NO NO IC501 pinD1 D2 E1 I2S Clock signal OK IC202 PWM data output signal OK IC501 pinE2 I2S data signal OK ...

Page 54: ...8 Q717 Q718 pin49 50 of IC202 FRONT signal OK pin13 of IC700 FRONT audio signal OK IC204 FRONT audio signal OK 66 V B 12 V 5 V Power voltage OK Q705 Q706 OK pin45 48 of IC202 MID or SW signal OK pin13 of IC701 IC705 MID or SW audio signal OK IC204 IC205 MID or SW audio signal OK 66 V B 12 V 5 V Power voltage OK Q707 Q708 Q717 Q718 OK NO NO NO NO NO NO NO NO NO NO YES YES YES YES YES YES YES YES YE...

Page 55: ...TRICAL TROUBLESHOOTING GUIDE 4 NO LIGHTING SPEAKER LED YES YES NO YES Power on Replace Q616 Q618 Push the LIGHTING button Trun on the LED Check speaker Check IC601 NO NO Check Q616 Q618 LED_5 V IC601 LED 5 V OK ...

Page 56: ...3 35 WAVEFORMS OF MAJOR CHECK POINT 1 DSP IC501 X XI XO X XI XO Fig 1 2 Crystal of system 24 MHz Main DSP R508 C503 X500 Fig 1 1 Crystal of RTC 32 768 kHz Both ends of R5D6 X501 2 1 3 4 4 3 2 1 MBER ...

Page 57: ...3 36 2 PWM IC202 X XI XO Fig 2 2 DSP to PWM I2S IC202 pin26 30 Fig 2 1 Crystal 24 576 MHz IC202 pin4 5 X200 6 5 7 8 9 7 8 9 6 5 ...

Page 58: ...3 37 3 SERVO IC401 X XI XO Fig 3 2 CD 16M IC401 pin31 Fig 3 1 Crystal 16 9344 MHz X400 11 10 12 10 11 12 ...

Page 59: ...g 4 1 LO LO MOT_OPEN MOT_CLOSE for Driving TRAY Motor IC400 pin6 7 9 10 16 15 14 13 Fig 4 3 SP SP for Driving SPINDLE Motor IC400 pin17 18 20 19 Fig 4 2 SL SL for Driving SPINDLE Motor IC400 pin11 12 18 17 16 14 15 13 20 19 18 17 ...

Page 60: ...3 39 5 ADC IC201 6 USB CN502 Fig 6 USB D D CN502 pin5 6 8 9 Fig 5 ADC I2S IC201 pin42 43 44 23 21 22 24 25 24 25 21 22 23 ...

Page 61: ...3 40 7 BLUETOOTH CN504 B BT_TX BT_RX BT_RST BT_TX BT_RX BT_RST BT_TX BT_RX BT_RST Fig 7 BT_TX BT_RX BT_RST CN504 pin4 6 9 28 26 27 28 26 27 ...

Page 62: ...DRIVE IRS2092 IC701 GATE DRIVE IRS2092 IC705 GATE DRIVE IRS2092 Q705 Q706 IRF6775M Q707 Q708 IRF6775M Q717 Q718 IRF6775M IC602 DAC PCM5101 Tuner MIC MIC PTB 33pin 33pin 12pin 10pin 12pin 10pin 10pin 10pin 23pin 23pin 10pin USB1 USB2 10pin 10pin VFD Board Top Board MAIN Board Front Board 10pin 10pin BT module AUX IN OUT SPK LED SPK Front SPK Woofer IC204 S4308 IC205 S4308 MD 15pin 6pin 15pin 6pin S...

Page 63: ... M00_15 A00_16 SF_DI DO SF_CS SCK VFD_STB CLK DO RST VKK FL RMC MAIN VOL_A B KEY 1 2 500 W OP_SW CL_SW UP_SW DN_SW D_SENSE MOT_MUTE CLOSE OPEN A B C D E F PD LD SPDO SLDO FOD TRD LOAD SLED SPIN TR F D2S IR_IN_SW PWM_LRCK BCK DATA DSP_O_DATA AUX_DATA EXP_DATA MCS_BCK LRCK MCLK CD_RW MCLK LRCK BCK CD_DAT CD_RST UART_RX TX BT_TX RX BT_PCM_BUFFER D1 OM7550 Total 1000 W MID 500 W X 1 CH FRONT 500 W X 1...

Page 64: ... 10mA 10mA 80mA 22mA IC603 EXPENDER BU2090F TU500 TUNER 10mA 70mA IC604 DRV632 25mA 160mA 80mA 20mA RC311 RMC IC504 F S 1Mb W25Q80 IC102 RESET IC AZ7027 15mA 20mA 2mA 38mA 6mA 2mA IC311 VFD 5mA IC103 P_SENSE 2mA 350mA 5VU 1A IC601 LDO LM37102 LED_5V 100mA 3 Color LED 1EA 2mA FAN 230mA IC207 LM37102 6mA 6mA IC700 GATE DRIVE IRS2092 IC701 GATE DRIVE IRS2092 IC705 GATE DRIVE IRS2092 20mA 20mA 20mA 6m...

Page 65: ...CE IMPROVEMENT CHANGES INTO THE SET IS NOT DELAYED UNTIL THE NEW SERVICE LITERATURE IS PRINTED 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 IMPORTANT SAFETY NOTE 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 POWER_1 EAX66475001 SD 01 _Rev1 1_1 2015 04 14 CAUTION Danger if fus...

Page 66: ...ANCE IMPROVEMENT CHANGES INTO THE SET IS NOT DELAYED UNTIL THE NEW SERVICE LITERATURE IS PRINTED 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 IMPORTANT SAFETY NOTE 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 POWER_2 EAX66475001 SD 02 _Rev1 1_1 2015 04 14 Warning Parts that ...

Page 67: ...3 51 3 52 3 MAIN_CD DSP CIRCUIT DIAGRAM 28 26 27 4 3 24 2 25 1 WAVEFORM NUMBER 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 MAIN_CD DSP EAX66487701 SD 01 _Rev1 5_12 2015 07 29 ...

Page 68: ...3 53 3 54 4 MAIN_ADC PWM CIRCUIT DIAGRAM 21 22 23 7 8 9 6 5 WAVEFORM NUMBER 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 MAIN_ADC PWM EAX66487701 SD 02 _Rev1 5_12 2015 07 29 ...

Page 69: ...3 56 5 MAIN_RF SERVO CIRCUIT DIAGRAM 10 11 12 16 14 15 13 20 19 18 17 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 MAIN_RF SERVO EAX66487701 SD 03 _Rev1 5_12 2015 07 29 WAVEFORM NUMBER ...

Page 70: ...3 57 3 58 6 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 MAIN_AMP EAX66487701 SD 04 _Rev1 5_12 2015 07 29 ...

Page 71: ...3 59 3 60 7 MAIN_AUX OUT VFD PWR 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 MAIN_AUX OUT VFD EAX66487701 SD 05 _Rev1 5_12 2015 07 29 ...

Page 72: ...3 61 3 62 8 FRONT 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 FRONT EAX66449901 SD_Rev1 4_7 2015 07 29 ...

Page 73: ...3 63 3 64 9 VFD RMC1 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 VFD RMC1 EAX66468901 SD_Rev1 5_12 2015 07 29 ...

Page 74: ...3 65 3 66 10 TOP 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 TOP EAX66450001 SD_Rev1 5_8 2015 07 29 ...

Page 75: ...G 8MBIT Vcc 2 7 3 6V Vcc 3 37V Vcc 3 37V IC505 LDO Voltage Requlator TJ4220GDP ADJ Vin 2 5 6 5V Vout 2 5 5V Vin 4 90V Vout 3 33 V Vin 4 91V Vout 3 33 V IC507 IC508 Voltage Regulator AZ1117BH ADJTRE1 Vin Max 12V Vout Max 10V Vin 5 12V Vout 3 36V Vin 5 12V Vout 3 36V IC600 DC DC Converter TPS54331D VIN 3 5 28V VIN 12 67V VIN 12 67V IC602 D A Converter PCM5101APWR CPVDD AVDD DVDD 3 0 3 6V CPVDD AVDD ...

Page 76: ...L 22 10 22 22 1 0 22 22 1 0 16 3 3V 3 3 10 3 37 2 1 3 35 1 5 MAIN TOP USB CN502 MAIN CNA203 TOP 2 3 5 6VA 5 6 10 5 64 0 7 5 64 0 7 MAIN BT Module CN504 MAIN BT Module 10 3 3VA 3 3 10 3 329 0 9 3 329 0 9 MAIN Pick up MD CN400 MAIN MD 8 DVCC_5V 5 10 5 01 0 2 5 01 0 2 MAIN FAN Module CN604 MAIN FAN Module 4 12V 12 10 11 98 0 2 11 98 0 2 FRONT MAIN CNA304 FRONT CN201 MAIN 6 3 3V 3 3 10 3 244 1 7 3 244...

Page 77: ...3 71 3 72 PRINTED CIRCUIT BOARD DIAGRAMS 1 SMPS P C BOARD TOP VIEW NOTE Warning Parts that are critical with respect to risk of fire or electrical shock ...

Page 78: ...3 73 3 74 2 SMPS P C BOARD BOTTOM VIEW NOTE Warning Parts that are critical with respect to risk of fire or electrical shock ...

Page 79: ...3 75 3 76 3 MAIN VFD RMC1 P C BOARD TOP VIEW ...

Page 80: ...3 77 3 78 4 MAIN VFD RMC1 P C BOARD BOTTOM VIEW ...

Page 81: ...3 79 3 80 5 FRONT P C BOARD TOP VIEW 6 FRONT P C BOARD BOTTOM VIEW ...

Page 82: ...3 81 3 82 7 TOP VOLUME_FR1 P C BOARD TOP VIEW ...

Page 83: ...3 83 3 84 8 TOP VOLUME_FR1 P C BOARD BOTTOM VIEW ...

Page 84: ...e 2 2 2 Magnet 2 2 3 Clamp 2 3 Tray Disc 3 4 Pick Up Assembly 4 5 Base Up Down 4 6 Belt Loading 5 7 Gear Pulley 5 8 Gear Loading 5 9 Guide 5 10 Deck PCB Assembly 5 11 Motor Assembly 5 12 FFC Cable 5 DECK MECHANISM EXPLODED VIEW DM19AA 6 APPENDIX MECHANISM DM19AA CONTENTS ...

Page 85: ...mp Assembly as Figure B 2 Bending the Cover Top in direction of arrow 2 as Figure B 3 Separate the Clamp Assembly from the Cover Top 2 1 Plate 1 Turn the Plate to a counterclockwise direction and then lift up the Plate 2 Remove the Plate 2 2 Magnet Remove the Magnet 2 3 Clamp Remove the Clamp 1 3 S1 Cover Top Figure A L1 2 1 2 Figure B Clamp Assembly Clamp Assembly Plate Magnet Clamp ...

Page 86: ...ote When reassembling place the Guide as Figure E MD Sub Assembly Figure D 3 1 1 2 2 Tray Disc Tray Disc Figure E Guide 3 Tray Disc 1 Insert and push a flat head screwdriver in the Emergency eject hole H1 at the right side so that the Tray Disc is ejected about 15 20 mm 2 Pull the Tray Disc until it is locked Bottom side view Tray Disc Tray Disc Figure C 2 1 H1 Emergency eject hole ...

Page 87: ...eassembling insert the D portion of the Base Up Down in the Hole H2 of the Base Main as Figure G 3 3 2 Base Up Down Figure G 2 Figure G 1 C B Guide Base Up Down Base Main Figure G B H2 A Figure G 3 D 1 L2 4 Pick Up Assembly 1 Detach the Gasket Tape 2 Disconnect the wires BLK RED BRN ORN from the Deck PCB Assembly by desoldering 3 Remove the 4 screws S2 4 Disconnect the FFC Cable from the Pick Up A...

Page 88: ...B Assembly 1 Disconnect the wires RED BK form the Deck PCB Assembly by desoldering 2 Remove the 1 screw S3 3 Separate the Deck PCB Assembly from the Base Main 11 Motor Assembly Unlock the Locking Tab L4 in direction of arrow and then separate the Motor Assembly from the Base Main 12 FFC Cable Remove the FFC Cable Gear Pulley Belt Loading Deck PCB Assembly Motor Assembly Base Main Gear Loading Guid...

Page 89: ...6 DECK MECHANISM EXPLODED VIEW DM19AA 1439 A001 1002 1005 1001 1049 1437 1437 1024 1024 1024 1024 1003 1011 1437 1004 1026 1030 1043 1045 A005 A006 1016 1013 1015 1020 1439 1018 1019 1012 1006 ...

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LG OM7550, Service Manual

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Summary of Contents for OM7550

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