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LG LF-U850A, Service Manual

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LG LF-U850A Service Manual Download Page 20

2-16

2-17

• FRONT SCHEMATIC DIAGRAM

Summary of Contents for LF-U850A

Page 1: ...MICRO HI FI SYSTEM SERVICE MANUAL MODEL LF U850D LF U850A LFS U850 SERVICE MANUAL MODEL LF U850D LF U850A LFS U850 CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL ...

Page 2: ...HOOTING GUIDE 2 1 INTERNAL BLOCK DIAGRAM of ICs 2 6 BLOCK DIAGRAM 2 12 SCHEMATIC DIAGRAMS 2 14 CD PART 2 20 WIRING DIAGRAM 2 26 PRINTED CIRCUIT BOARD DIAGRAM 2 28 SECTION 3 EXPLODED VIEWS CABINET AND MAIN FRAME SECTION 3 1 Deck Mechanism Exploded View 3 3 SECTION 4 SPEAKER PART MODEL LFS U850 4 1 SECTION 5 REPLACEMENT PARTS LIST 5 1 ...

Page 3: ...ver 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 be cleaned away by using an air bush such as used for camera lens The lens is held by a delicate spring When cleaning t...

Page 4: ...tive 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 1M Ω 6 Care should be taken not to permit the laser pick up to come in contact with clothing in order to prevent sta tic electricity changes in the clothing to...

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: ...requency Response 60 10000 Hz Tuning Range 522 1620 kHz or 520 1720 kHz Intermediate Frequency 450 kHz Signal to Noise Ratio 34 dB Frequency Response 120 2000 Hz Output Power 80 W 80 W T H D 0 5 Frequency Response 42 20000 Hz Signal to noise ratio 75 dB Type Bass Reflex 3Way 4Speaker Impedance 6 Ω Frequency Response 60 20000 Hz Sound Pressure Level 82 dB W 1m Rated Input Power 80 W Max Input Power...

Page 7: ...302 OPERATION AND INPUT VOLTAGE 4 7V 5 0V CHECK YES YES U COM 26PIN 5V CHECK YES IC302 INPUT VOLTAGE 4 7V OR ABOVE OUTPUT VOLTAGE 3V OR ABOVE OPERATION CHECK IC304 KIA7042 REPLACEMENT NO YES VKK CHECK CN943 6PIN DC 33V CHECK MAIN PCB PN101 6PIN VOLTAGE 33V CHECK REFER TO SMPS TROUBLESHOOTING YES YES NO MAIN PCB PATTERN DISCONNECTION CHECK NO PN304 3PIN VOLTAGE CHECK 33V YES FFC WIRE ASSEMBLY STATU...

Page 8: ...IN 4 7V 5V CHECK FRONT PCB PATTERN DISCONNECTION CHECK YES NO Q303 A103S BASE HIGH CHECK Q301 Q302 Q502 Q503 D1304S BASE HIGH CHECK C COM 10PIN HIGH OPERATION STATUS CHECK YES IC603 CS5340 10PIN 12PIN INPUT CHECK IC603 CS5340 2PIN MCLK 4PIN SDOUT 7PIN SCLK 8PIN LRCK OUTPUT WAVEFORM CHECK YES Q303 A103S OPERATION STATUS CHECK YES REPLACE Q303 A103S IF FAULTY YES MUTE YES NO REPLACE EACH APPROPRIATE...

Page 9: ... VSS POWER CHECK REPLACE APPROPRIATE PARTS YES YES YES YES NORMAL REPLACE APPROPRIATE PARTS YES YES NORMAL NORMAL IC602 MC4580 4PIN VSS 8PIN VDD POWER CHECK REFER TO SMPS TROUBLESHOOTING PN805 ASSEMBLY STATUS CHECK YES IC602 MC4580 2 6PIN INPUT WAVEFORM CHECK YES NO NO IC601 BU4052 3 13PIN OUTPUT WAVEFORM CHECK YES NO YES FRONT CN304 MAIN PCB PN302 FFC WIRE contact and assembly status check NO REP...

Page 10: ...R CHECK REPLACE APPROPRIATE PARTS YES YES YES YES NORMAL REPLACE APPROPRIATE PARTS YES YES NORMAL NORMAL IC602 MC4580 4PIN VSS 8PIN VDD POWER CHECK REFER TO SMPS TROUBLESHOOTING JK601 CONTACT STATUS CHECK YES IC602 MC4580 2 6PIN INPUT WAVEFORM CHECK YES NO NO IC601 BU4052 3 13PIN OUTPUT WAVEFORM CHECK YES NO YES FRONT CN304 MAIN PCB PN302 FFC WIRE contact and assembly NO REPLACE FAULTY PARTS ...

Page 11: ...WER CHECK REPLACE APPROPRIATE PARTS YES YES YES YES NORMAL REPLACE APPROPRIATE PARTS YES YES NORMAL NORMAL IC602 MC4580 4PIN VSS 8PIN VDD POWER CHECK REFER TO SMPS TROUBLESHOOTING TUNER MODULE TU601 OPERATION CHECK YES IC602 MC4580 2 6PIN INPUT WAVEFORM CHECK YES NO NO IC601 BU4052 3 13PIN OUTPUT WAVEFORM CHECK YES NO YES FRONT CN304 MAIN PCB PN302 FFC WIRE CONTACT AND ASSEMBLY STATUS CHECK NO REP...

Page 12: ...andpass 6 25kHz Bandpass 16kHz Bandpass Peak Detector Peak Detector Peak Detector Peak Detector Peak Detector Clock Oscillator Anti Alias Filter ResetStrobe Audio In CKIN DCOut Peak Detector Peak Detector 63Hz Bandpass 160Hz Bandpass UTC MC4580 PIN CONFIGURATION 1 2 3 4 8 7 6 5 OUT2 IN2 IN1 Vcc Vcc OUT 1 IN1 IN2 ...

Page 13: ...ter Internal Clocks Internal Control SUB SLRCK SBCK SDIN OSC_IN PLL_EXT_LPF SCL SDA I2 C Interface PWM_CH1_P PWM_CH1_M PWM_CH2_P PWM_CH2_M PWM_CH3_P PWM_CH3_M OVERLOAD NRESET SA MAIN MLRCK MBCK MDIN EPD_ENA 3 or 5 Band EQ Dynamic Bass Boost PWM_LOL_P PWM_LOL_M PWM_LOR_P PWM_LOR_M PWM_HP_L PWM_HP_R PIN ASSIGNMENT 5 VDDA CKIN VSSA RESET OUT GND STROBE IN ...

Page 14: ...rates 12 288MHz clock and the internal PLL generates 98 304MHz 12 288MHz x 8 system clock SA 7 I Slave Address Set for Host Interface PLL_EXT_LPF 3 Analog External PLL low pass filter pin PCM Audi o Input Outp ut Interface MLRCK 14 I O PCM Word clock left right clock input output of main 2 channel audio User can select the master slave mode of this signal Schmitt Trigger input MBCK 15 I O PCM bit ...

Page 15: ...tput of Line out left PWM_LOL_M 33 O Negative PWM output of Line out left PWM_LOR_P 32 O Positive PWM output of Line out right PWM_LOR_M 31 O Negative PWM output of Line out right PWM_HP_L 29 O Positive PWM output of headphone left channel PWM_HP_R 28 O Positive PWM output of headphone right channel System Control Interface SDA 9 I O SDA for I2C mode SCL 8 I SCL for I2C mode Schmitt Trigger input ...

Page 16: ...ode 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 H Bridge 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 Caps 2nd Order L C Output Filter for Each Half Bridge SD OTW Out...

Page 17: ... 4 Protection and I O Logic PWM_C OUT_C GND_C PVDD_C BST_C Timing Gate Drive Ctrl PWM Rcv GVDD_C PWM_B OUT_B GND_B PVDD_B BST_B Timing Gate Drive Ctrl PWM Rcv GVDD_B PWM_A OUT_A GND_A PVDD_A BST_A Timing Gate Drive Ctrl PWM Rcv GVDD_A Ctrl BTL PBTL Configuration Pulldown Resistor BTL PBTL Configuration Pulldown Resistor BTL PBTL Configuration Pulldown Resistor BTL PBTL Configuration Pulldown Resis...

Page 18: ... BLOCK DIAGRAM 2 12 2 13 ...

Page 19: ...2 14 2 15 SCHEMATIC DIAGRAMS MAIN SCHEMATIC DIAGRAM ...

Page 20: ...2 16 2 17 FRONT SCHEMATIC DIAGRAM ...

Page 21: ...2 18 2 19 SMPS SCHEMATIC DIAGRAM ...

Page 22: ...2 20 2 21 CD PART WMA MODULE ...

Page 23: ...2 22 2 23 USB PART ...

Page 24: ...2 24 2 25 WMA USB BLOCK DIAGRAM ...

Page 25: ...2 26 2 27 WIRING DIAGRAMS ...

Page 26: ...2 28 2 29 PRINTED CIRCUIT DIAGRAMS MAIN P C BOARD COMPONENT SIDE ...

Page 27: ...2 30 2 31 MAIN P C BOARD SOLDER SIDE ...

Page 28: ...2 32 2 33 SMPS P C BOARD ...

Page 29: ...2 34 2 35 FRONT P C BOARD ...

Page 30: ...3 36 3 37 CD P C BOARD COMPONENT SIDE CD P C BOARD SOLDER SIDE ...

Page 31: ......

Page 32: ...S CABINET AND MAIN FRAME SECTION 260 A26 A41 255 256 250 251 450 252 450 253 305 A47 254 A43 258 259 451 257 A42 270 453 A46 280 450 271 NOTE Refer to SECTION 6 REPLACEMENT PARTS LIST in order to look for the part number of each part ...

Page 33: ...30X 003 4860RB0002A CLAMP HOME CDM H1503 MOLD DISC 004 4930R 0526A HOLDER HOME CDM 310 MOLD CLAMP 011 3040R 0073A BASE P U CDM 300 012 5040R 0131A RUBBER HOME CDM 310 OTHER DAMPER 013 4400R 0006B BELT DECK MECHA DP2 5 DP7C DP7A OT 014 4470R 0055A GEAR PULLEY 015 6871RC2016A PWB PCB ASSEMBLY CD LOADING CDM 300 017 4470R 0056A GEAR LOADING 018 4974R 0023A GUIDE UP DOWN 020 3040R M059A BASE MAIN CDM ...

Page 34: ... 4 1 SECTION 4 SPEAKER PART 858 859 860 870 869 868 867 866 864 862 863 857 872 853 855 850 851 852 875 865 856 873 854 861 RIGHT 871 LEFT MODEL LFS U850 ...

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