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LG LPA-172G, Service Manual

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LG LPA-172G Service Manual Download Page 10

1) Power measuring

Measure each power after power supply.
C83(-) : -14.5V, C82(+) : +15V,C100 : +7.5V,C97(+) : +5V,C43(+) : 3.3V

2) VCOM waveform adjustment

Adjust the VCOM level while changing the VR1 as below waveform by using the scope in the
C84.

3-2

Vcom Waveform

63.5

63.5µs

5.

5.3Vp-p

3Vp-p

0.7V

4.6V

GND

GND

LCD PART

Summary of Contents for LPA-172G

Page 1: ...BLE DVD SERVICE MANUAL MODEL LPA 735 DP171 172G BP 173G CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL MODEL LPA 735 DP171 172G BP 173G SERVICE MANUAL P NO AFN31223611 JULY 2006 ...

Page 2: ...1 1 CONTENTS SECTION 1 SUMMARY SECTION 2 EXPLODED VIEWS SECTION 3 ELECTRICAL SECTION 4 REPLACEMENT PARTS LIST ...

Page 3: ...1 2 SECTION 1 SUMMARY CONTENTS PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS 1 3 SERVICING PRECAUTIONS 1 4 SPECIFICATIONS 1 5 ...

Page 4: ...AYS WHEN THE HIGH VOLTAGE IS AT THE FACTORY SPECIFIED LEVEL THE PROPER VALUE IS GIVEN IN THE APPLICABLE SCHEMATIC OPERA TION AT HIGHER VOLTAGES MAY CAUSE A FAILURE OF THE PIC TURE TUBE OR HIGH VOLTAGE SUPPLY AND UNDER CERTAIN CIR CUMSTANCES MAY PRODUCE RADIATION IN EXCESS OF DESIR ABLE LEVELS 2 ONLY FACTORY SPECIFIED C R T ANODE CONNECTORS MUST BE USED DEGAUSSING SHIELDS ALSO SERVE AS X RAY SHIELD...

Page 5: ...s including Metal pan els Input terminals Earphone jacks etc Electrostatically Sensitive ES Devices Some semiconductor solid state devices can be damaged easily by static electricity Such components commonly are called Electrostatically Sensitive ES Devices Examples of typical ES devices are integrated circuits and some field effect transistors and semiconductor chip components The following techn...

Page 6: ...re than 95dB Harmonic distortion audio 0 08 Operatingconditions audio Temperature 41 F to 95 F Operation status Horizontal Connectors Video input output VIDEO IN OUT 1 0V P P 75R negative sync ø3 5m X 1 Audio output optical audio Optical connector ø3 5mm X 1 Audio input output 2 0Vrms 1 KHZ 0 dB ø3 5m X 1 AUDIO IN OUT analog audio Earphone terminal ø3 5mm stereo mini jack X 1 Liquid Crystal Displa...

Page 7: ...2 1 2 1 SECTION 2 EXPLODED VIEWS CONTENTS EXPLODED VIEWS 2 2 CABINET AND MAIN FRAME SECTION 2 2 ...

Page 8: ... 2 2 EXPLODED VIEWS CABINET AND MAIN FRAME SECTION A48 A40 293 278 275 281 285 A46 A47 A42 A00 283 282 296 295 292 A51 272 277 277 267 284 275 262 260 266 265 264 A49A A46A A45A A44A LCD A 5 4 3 2 1 B C D ...

Page 9: ...CD BLOCK DIAGRAM 3 5 LCD CIRCUIT DIAGRAMS 3 7 LCD PRINTED CIRCUIT DIAGRAMS 3 9 MAIN PART 3 11 MAIN ELECTRICAL TROUBLE SHOOTING GUIDE 3 11 DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING 3 19 MAIN BLOCK DIAGRAMS 3 28 MAIN CIRCUIT DIAGRAMS 3 30 MAIN PRINTED CIRCUIT DIAGRAMS 3 56 ...

Page 10: ...wer supply C83 14 5V C82 15V C100 7 5V C97 5V C43 3 3V 2 VCOM waveform adjustment Adjust the VCOM level while changing the VR1 as below waveform by using the scope in the C84 3 2 Vcom Waveform 63 5 63 5µs 5 5 3Vp p 3Vp p 0 7V 4 6V GND GND LCD PART ...

Page 11: ...ace IC U1 Check and Replace D2 D3 D8 Check Main B D on located IC U6 Check and Replace A V IN S W Check IC U2 Check and Replace IC U3 Check and Replace FUSE NORMAL IC U1 NORMAL OPERAE 7 5V 15V 14 5V NORMAL 5V NORMAL Y C DISPLAY SIGNAL R G B SIGNAL OUTPUT VCOM SIGNAL 5 5VPP YES YES NO NO NO NO NO NO NO YES YES YES YES LCD TROUBLE SHOOTING GUIDE ...

Page 12: ...MAIN B D Check Power source and D2 D3 U4 Check TFT LCD PRESSURE VOLTAGE 15V 14 5V 5V TFT LCD NORMAL Replace COLOR ADJUSTING NORMAL Readjust as adjustement standard EACH CONNECTOR Replace and Reassemble END Replace YES YES YES YES YES NO NO NO NO NO NO ...

Page 13: ......

Page 14: ...LCD BLOCK DIAGRAM TFT LCD 7 WIDE INVERTER TERAMINS T100 DC DC CONV OEH OEV STV STH CKV VCOM RGB SY SC CVBS 15V 14 5V 7 5V 5V 3 5 3 6 ...

Page 15: ...67 70 76 1 7 9 15 17 23 63 66 69 75 26 47 56 80 46 57 78 96 95 27 35 60 77 89 91 AC0 ACB0 AC1 ACB1 AC2 ACB2 CVBS0 AY0 CVBS1 AY1 CVBS2 AY2 CVBS3 ACR0 CVBS4 ACR1 CVBS5 ACR2 CBMID CRMID CGMID IICA3 SDA SCANB SCL VDT0 VDT1 VDT2 VDT3 VDT4 VDT5 VDT6 VDT7 VCLK XTALI XTALO XCLK2MC RSTB CPUINT SCANST PWM VBIVALID XbusRD FIELD XbusWR RL UD STV1 STV2 GOE GCLK LP OEH POL VCOM HSO STH1 HSO STH2 DE CPH1 LLCK1 C...

Page 16: ...3 9 3 10 LCD PRINTED CIRCUIT DIAGRAMS 1 MAIN P C BOARD TOP VIEW TOP VIEW BOTTOM VIEW ...

Page 17: ......

Page 18: ...APTOR Replace ADAPTOR Is ADAPTOR OUT 9 5V A Is1D3 OK NO NO Replace 1D3 NO NO YES YES YES NO POWER ON by BATTERY Replace BATTERY Is BATTERY OK A NO YES YES A YES NO 3 3V NO 1 8V Is IC 1U2 3 3v OK Replace IC 1U2 Is 1Q3 3 3V OK Replace IC 1Q3 NO LCD POWER NO 5V Replace IC 1U1 Replace7L1 MAIN PART ...

Page 19: ... YES YES YES YES Replace IC 4U3 VIDEO OUT ABNORMAL Check Video Jack Mode Check IC 8U1 Check Video signals from MPEG YES YES YES Check LC Filter YES AUDIO IN SPEAK ER ABNORMAL Check Audio Jack Mode S W Is Speakers OK Replace Is 7J2 OK Replace 7J2 Speakers Replace IC 5U1 VIDEO IN ABNORMAL Check Video Jack Mode Check 7J2 Is 8Q1 OK Replace 8Q1 Refer to LCD part 3 12 ...

Page 20: ...fer to Servo part YES YES YES YES Check MPEG IC 2U1 If OK YES If OK YES If OK YES If OK YES If OK YES If OK YES Replace B D DISC ERROR Check Disc Replace B D Refer to Servo part YES YES YES OPEN CLOSE ABNORMAL Check 2SW1 switch Refer to SERVO part Check IC 2U1 Pin 158 NO Check the connectin of MD YES YES Refer to SERVO part YES ...

Page 21: ...coder Does the Video of the video CD play properly Does the audio sound output normally END Check power clock Check CD DVD DSP output signal Check MPEG Decoder input signal Check CD DVD DSP output signal Check MPEG Decoder input signal Check CD DVD DSP output signal Check MPEG Decoder input signal Check clock signal Check clock signal YES YES YES YES YES YES YES YES YES YES NO NO NO OK OK OK OK NO...

Page 22: ...ection between 2J3 and MT1389 Proper RFL signal on MT1389 Laser off Proper DMSO signal on MT1389 Check DMSO related circuit on MT1389 Replace IC 5U1 Check the cable connection between spindle and main PCBA D A Check the related circuit on MT1389 RFL signal NO NO NO NO NO YES YES YES YES YES YES ...

Page 23: ...heck connections between MT1389 and pick up head NO Check the related circuit on MT1389 FEO sugnal Check the related circuit on MT1389 Check the TRSO connection on MT1389 and motor dirver T T output properly Check cable connection on pick up head Check RF signal waveform Check the tracking control amp circuit on motor driver NO NO NO NO NO NO NO YES YES YES YES YES YES YES YES YES YES ...

Page 24: ...ormal IR VFD Front pannel key functions TEST END Communications between IR VFD Front pannel key MT1389 Front u com is normally Check the cable connection on Front pannel C Check connection between MT1389 Audio DAC Check VRST ACLK ABCK ASDAT3 NO Check the related circuit of Audio DAC Check communi cation lines On MT1389 NO NO NO NO YES YES YES YES YES ...

Page 25: ...3 18 No turn on Red LED Is 9U1 OK Is 8 4V of 9J1_Pin4 OK NO Replace 9U1 NO Replace IC 9U4 NO Replace 9L1 NO Replace IC 9U3 NO YES Is IC9U4 OK YES Is 9L1 OK YES Is IC 9U3 OK YES Chargeing Circuit ...

Page 26: ...SYSTEM TEST AND DEBUGGING 1 SYSTEM 27MHz CLOCK RESET FLASH R W SIGNAL 1 MT1389 main clock is at 27MHz X500 3 8V 27MHz FIG 1 1 2 SDRAM CLOCK 1 MT1389 main clock is at 27MHz X501 IC500 PIN 229 228 DCLK 93MHz Vp p 2 2 Vmax 2 7V FIG 2 1 ...

Page 27: ...3 20 3 DISC TYPE JUDGEMENT WAVEFORM F IC200 PIN 24 FE IC500 PIN 31 RFL IC500 PIN 6 FIG 3 1 F IC200 PIN 24 FE IC500 PIN 31 RFL IC500 PIN 6 FIG 3 2 ...

Page 28: ...3 21 F IC200 PIN 24 FE IC500 PIN 31 RFL IC500 PIN 6 FIG 3 3 F IC200 PIN 24 FE IC500 PIN 31 RFL IC500 PIN 6 FIG 3 4 ...

Page 29: ...3 22 4 FOCUS ON WAVEFORM FE IC500 PIN 31 FOSO IC200 PIN9 F IC200 PIN 24 F IC200 PIN 23 FIG 4 1 FE IC500 PIN 31 FOSO IC200 PIN9 F IC200 PIN 24 F IC200 PIN 23 FIG 4 2 ...

Page 30: ...ORM NO DISC CONDITION DMSO 1 4V 1 8V IC501 PIN 18 SP 3 6V 2 4V IC202 PIN 10 SP 3 6V 4 8V IC202 PIN 11 FIG 5 1 6 TRACKING CONTROL RELATED SIGNAL System checking TE IC500 PIN 32 TRSO IC200 PIN 8 T IC200 PIN 20 T IC200 PIN 19 FIG 6 1 ...

Page 31: ...3 24 7 RF WAVEFORM RFOP 2 3V 1 1V IC500 PIN 25 RFON 0 8V 2 0V IC500 PIN 26 FIG 7 1 TE IC500 PIN 32 TRSO IC200 PIN 8 T IC200 PIN 20 T IC200 PIN 19 FIG 6 2 ...

Page 32: ...3 25 8 MT1389 AUDIO OPTICAL AND COAXIAL OUTPUT ASPDIF IC500 PIN 225 FIG 8 1 9 MT1389 VIDEO OUTPUT WAVEFORM 1 Full colorbar signal CVBS IC604 PIN 23 FIG 9 1 ...

Page 33: ...3 26 2 Y IC604 PIN 21 FIG 9 2 3 C IC604 PIN 26 FIG 93 ...

Page 34: ...3 27 10 AUDIO OUTPUT FROM AUDIO DAC 1 Audio L R FIG 10 1 JK601 PIN 4 5 2 Audio related Signal ASDAT0 IC301 PIN 3 ABCK IC301 PIN 4 ALRCK IC5301 PIN 5 ASDAT 0 FIG 10 2 ...

Page 35: ...5V PWRCTL_3 3V D 3 3V A 3 3V D 1 8V MPEG FRONT 15V 14 5V 7 5V CVBS JACK BATERY BLOCK BAT7 6V SP _AMP_EN MUTE_FM BF1_FM_CS VI DEO_IO_CON AUDIO_CD_CON VFD_TXD VFD_SCK MPEG FM_MUTE FM_CS FM_SCK FM_TXD FM A_VI DEO_IO_CON A_AUDIO_CK_CON A_SP_ AMP_EN AUDIO AV FD_TXK AVFD_SCK AVFD_CS 27MHz 5MHz BAT_SENCE DC_SENCE DC 9 5V FRONT BLOC K DISCI FRONT SPINDLE MOTOR STEPPING MOTOR M PICK UP M U201 BA5954 U202 B...

Page 36: ... Q107 SI4435D Y U5 AAT1102 U101 MP1410 U102 MP1410 U105 RT9701 U701 SI4435D Y U702 GT6312 U104 BD6111FV From AC Adapter 9 5v From BATTERY 7 6V To BATTERY CH_EN PWRCTL_3 3V PWRCTL_5V DCPWR E 5V S 5V A 5V A 5V D 3 3V A 3 3V D 1 8V 15V 14 5V 7 5V ...

Page 37: ......

Page 38: ...4 1TP14 1Q2 3904 1 3 2 1U3B LM393 5 6 7 8 4 1TP26 1C30 0 1uF 1Q1 AF2301P 1 3 2 1TP29 1TP30 1Q4 3904 1 3 2 1C15 0 1uF 1TP9 1C23 0 1uF 1TP3 1R2 10K 1U1 MP1411 1 2 3 4 6 7 8 9 5 10 NC BS NC IN GND FB COMP EN SW SS 1C1 103 1CE18 220uF 10V 1FB6 50 1FB7 FB 1206 1R14 5 1K 1Q6 3904 1 3 2 1FB1 10uH 1C16 0 1uF 1TP22 1U3A LM393 3 2 1 8 4 1CE13 100uF 16V 1CE1 220uF 16V 1CE9 100uF 16V 1CE19 100uF 10V 1U4 CM111...

Page 39: ...00 101 102 103 104 105 107 108 162 161 160 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145 144 143 142 141 140 139 137 138 136 135 134 133 132 131 130 129 128 126 127 125 124 123 122 121 120 118 119 117 116 115 114 113 111 112 110 109 209 215 24 214 191 190 198 197 208 207 196 211 206 203 201 202 200 199 194 195 192 184 185 182 181 180 179 186 178 177 175 173 174 164 171 170 169 168 17...

Page 40: ... 3TP36 3TP30 3C6 0 1uF 3R9 10 3TP4 3RN1 33x4 1 8 2 7 3 6 4 5 3TP27 3TP38 3TP15 3TP20 3C1 0 1uF 3TP32 3TP6 3TP10 3CE1 100uF 6 3V 3U1 EEPROM 24C16 SOP8 1 2 3 4 5 6 7 8 NC NC NC GND SDA SCL WP VCC 3C5 0 1uF 3C10 open 3TP14 3TP22 3TP17 3TP9 3C12 0 1uF 3TP7 3TP29 3TP19 3L1 FB 3TP33 3TP26 3TP16 3C4 0 1uF 3TP5 3TP24 3U3 STM29W160 MX29LV800 160 25 24 23 22 21 20 19 18 8 10 28 47 16 29 31 33 35 7 26 38 40 ...

Page 41: ...00uF 16V 4R10 0 4R9 100K 4R28 20K 4C14 OPEN 12pF 4TP15 4R12 OPEN 100K 4R41 10K Drive IC LED 4J1 GP1FD310TP 5 4 3 6 8 7 2 1 4CE7 10uF 25V 4R24 47K 4TP5 4C4 0 1uF 4C12 56pF 4R19 12k 4C3 22p 4R4 NC 0 4TP34 4TP16 4U3 CS4344 1 2 3 4 6 7 8 9 5 10 SDATA SCLK LRCK MCLK FILT AOUTL GND VA VQ AOUTR 4R8 OPEN 180K 4Q1 3904 1 3 2 4CE12 NC 47U 10V 4TP26 4CE3 47uF 10V 4R21 4 7K 4CE5 47UF 10V 4CE10 10uF 25V 4TP3 4...

Page 42: ...25 5C3 1UF 50V 5J2 PHONEJACK 3 6 5 4 2 1 7 8 5J1 PHONEJACK 3 6 5 4 2 1 7 8 5R5 1K 5CE1 22UF 16V 5C8 0 1uF 5TP19 5R4 10K 5Q2 3904 1 3 2 5R1 47k 1 5R6 1K 5TP27 5TP13 5Q7 3904 1 3 2 5R11 100 5R19 10k 1 5CE5 10uF 25V 5TP7 5CE4 10uF 25V 5TP20 5R10 100 5C2 C 5Q5 3904 1 3 2 5R15 4 7K 5Q3 3904 1 3 2 5CE6 22UF 16V 5R14 4 7K 5TP14 5R8 100K 5TP23 5R18 10k 1 5Q4 3904 1 3 2 5TP12 5R12 4 7K 5R13 4 7K 5Q1 3904 1...

Page 43: ... 5 AV_IN OUT_DET 1 4 VCC_3V3 1 4 GREEN 9 RED 9 5V 6R17 4 7K 6CE3 47uF 10V 6TP21 6CE1 10UF 25V 6Q3 2N3904 1 3 2 6TP10 6R11 10K 6R12 4 7K 6D2 1N4148 1 2 6TP24 6R10 4 7k 6R15 10K 6C6 20pF 6TP22 6TP9 6R14 470 6C2 20p 6R2 100 6R7 470 6TP11 6TP16 6C3 20p 6R13 100 6TP20 6CE2 10uF 25V 6TP23 6R8 470 6RN1 10Kx4 1 8 2 7 3 6 4 5 6Y1 4MHz 3 6TP17 6D3 LED3 6TP12 6Q2 2N3904 1 3 2 6RN3 10Kx4 1 8 2 7 3 6 4 5 6R3 1...

Page 44: ...3 4 5 6 8 9 10 LCD_CTRL 6 LCD_5V LCD_5V 7C7 100pF 7R6 OPEN 75 1 7TP17 7R2 10K 7U1 EEPROM 24C16 SOP8 1 2 3 4 5 6 7 8 NC NC NC GND SDA SCL WP VCC 7R1 10K 7TP25 7TP6 7TP18 7C9 100pF 7TP12 7C1 0 1uF 7C6 0 1uF 7C4 47pF 7R3 10K 7TP9 7C8 100pF 7TP5 7J2 CON20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 7L2 1 8uH 7R4 OPEN 20K 7TP1 7TP21 7TP13 7TP26 7C3 47pF 7Q1 3904 1 3 2 7TP2 7R5 2K 7TP11 7TP7 7TP3...

Page 45: ... GND 1 2 3 4 5 6 7 9 10 CVBS_IN 7 AV_IN OUT_DET 4 8TP1 8C3 ESD 15pF 8R1 10K 8C8 22pF 8TP5 8R5 OPEN 8CE2 NC 8CE1 10uF 25V 8L1 FB 50 8R3 0 8J1 VIDEO IN OUT 2 3 4 1 5 6 8TP4 8Q2 3906 8R2 75 1 8L2 1 8uH 8TP3 8C2 47pF 8C1 104 8C4 ESD 15pF 8C6 100pF 8R6 10 8Q1 8TP2 8C7 100pF 8U1 FSAV330 14 2 5 11 3 6 10 13 1 8 15 4 7 9 12 16 4B1 1B1 2B1 3B1 1B2 2B2 3B2 4B2 S GND OE 1A 2A 3A 4A VCC 8R4 4 7K A 1 2 3 4 5 6...

Page 46: ...D_KEY6 2 DVD_KEY3 2 DVD_KEY5 2 DVD_KEY4 2 9V_IN 1 BAT_OUT 1 CHARGE_ENABLE 6 GND 1 2 3 4 5 6 7 9 10 RED 6 GREEN 6 K1 6 9R2 33 9C 15PF ESD 9J2 CON14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 9RN1 33x4 1 8 2 7 3 6 4 5 9C 15PF ESD 9J1 CON 12 1 2 3 4 5 6 7 8 9 10 11 12 9C 15PF ESD 9C 15PF ESD 9C 15PF ESD 9C 15PF ESD 9R1 33 9C 15PF ESD 9C 15PF ESD 9C 15PF ESD 9C 15PF ESD 9C 15PF ESD A 1 2 3 4 5 6 7 8 9 10 11 12 ...

Page 47: ...9R20 1K 9R24 470 9D4 1N4148 9R4 150K 1 9U1 FDS4435 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 9R21 51K 9U3 GT6312 CLV2 0 3 9 10 4 11 14 12 2 1 13 15 5 8 7 6 16 17 18 19 20 PORTD 2 PORTA 0 AN0 PORTA 1 AN1 PORTD 3 PWM1 PORTB 2 AN6 OSC1 PORTB 3 AN7 PORTE 3 PORTE 2 VDD PORTC 0 OSCO PORTC 3 PWM0 GND RESET PORTC 3 T0 PORTC 1VREF PORTD 0 PORTD 1 PORTE 0 PORTE 1 9TP9 9C11 104 9R17 2K 9TP16 9Q1 3904 9CE4 220uF 16V 9R...

Page 48: ...8 1 2 3 4 5 6 7 8 DISPLAY K11 1 2 MENU K5 1 2 TP1 TP2 C1 NC ESD 15pF LCD_MODE K10 1 2 POWER K12 1 2 SETUP K1 1 2 COLOR BRIGHT K13 1 2 RIGHT K8 1 2 TP6 C2 NC ESD 15pF AV_IN OUT K7 1 2 TP3 TP11 C5 NC ESD 15pF C11 NC ESD 15pF C10 NC ESD 15pF C6 NC ESD 15pF TITLE K6 1 2 TP8 C4 NC ESD 15pF C8 NC ESD 15pF LEFT K9 1 2 ENTER K4 1 2 TP5 TP9 TP4 C9 NC ESD 15pF J1 CON14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 TP10 ...

Page 49: ...3 DVD_KEY5 DVD_KEY4 DVD_KEY2 DVD_KEY3 DVD_KEY5 K2 GND PAUSE STOP K4 1 2 C3 NC ESD 15pF C4 NC ESD 15pF PLAY K1 1 2 J1 CON8 1 2 3 4 5 6 7 8 PREC K3 1 2 C5 NC ESD 15pF C2 NC ESD 15pF NEXT K2 1 2 C1 NC ESD 15pF 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 ...

Page 50: ...3 54 3 55 MAIN PRINTED CIRCUIT DIAGRAMS 1 MAIN P C BOARD TOP VIEW ...

Page 51: ...3 56 3 57 2 MAIN P C BOARD BOTTOM VIEW ...

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