LG RT-20LA90 Service Manual Download

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LCD TV

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS : ML-041B

MODEL : RZ-20LA90/RT-20LA90

website:http://biz.LGservice.com

e-mail:http://www.LGEservice.com/techsup.html

Summary of Contents for RT-20LA90

Page 1: ...ERVICE MANUAL CAUTION BEFORE SERVICING THE CHASSIS READ THE SAFETY PRECAUTIONS IN THIS MANUAL CHASSIS ML 041B MODEL RZ 20LA90 RT 20LA90 website http biz LGservice com e mail http www LGEservice com techsup html ...

Page 2: ...TENTS 2 PRODUCT SAFETY 3 SPECIFICATION 6 ADJUSTMENT INSTRUCTION 10 HOTEL MODE 12 TROUBLE SHOOTING 15 BLOCK DIAGRAM 20 WIRING DIAGRAM 22 EXPLODED VIEW 23 EXPLODED VIEW PARTS LIST 24 REPLACEMENT PARTS LIST 26 SVC SHEET ...

Page 3: ...et such as antennas terminals etc to be sure the set is safe to operate without damage of electrical shock Leakage Current Cold Check Antenna Cold Check With the instrument AC plug removed from AC source connect an electrical jumper across the two AC plug prongs Place the AC switch in the on position connect one lead of ohm meter to the AC plug prongs tied together and touch other ohm meter lead i...

Page 4: ...vely obtain and wear a commercially available discharging wrist strap device which should be removed to prevent potential shock reasons prior to applying power to the unit under test 2 After removing an electrical assembly equipped with ES devices place the assembly on a conductive surface such as aluminum foil to prevent electrostatic charge buildup or exposure of the assembly 3 Use only a ground...

Page 5: ...not shiny reheat them and if necessary apply additional solder Fuse and Conventional Resistor Removal Replacement 1 Clip each fuse or resistor lead at top of the circuit board hollow stake 2 Securely crimp the leads of replacement component around notch at stake top 3 Solder the connections CAUTION Maintain original spacing between the replaced component and adjacent components and the circuit boa...

Page 6: ...Display Area Pixel Pitch mm Electrical Interface Color Depth Size mm Surface Treatment Operating Mode Back light Unit R T Typ Maker Type ActiveDisplay Area Pixel Pitch mm Electrical Interface Color Depth Size mm Surface Treatment Operating Mode Back light Unit R T Typ LPL TFT Color LCD Module 20 1 inches 510mm diagonal 0 6375mm H x0 6375mm V xRGB TTL 8BIT 16 777 216 colors 450 H x 348 7 V x20 D Gl...

Page 7: ...1 Full SCART 1 1 1 1 BG DK BG I LL BG DK BG I LL X X X X O X X X X X X X X Item Specification Remark No Top option PAL NTSC Rear Rear Rear option NTSC Non EU Rear option EU Only Commercial Model Only Commercial Model 5 Optical Character Item Remark Specification Viewing Angle CR 10 Luminance Contrast Ratio CIE Color Coordinates Typical MAX MIN ALL white All black R L U D Luminance cd Variation LPL...

Page 8: ... 1 Contrast Brightness 2 H Position V Position 3 Tracking Clock Phase 4 Auto Configure RESET 1 Y 3 Pb 5 Pr 1 Y GND 2 Pb 5 Pr 7 LINE1 Ready 9 Line2 11 Line3 13 Line3 ready 2 Green 4 ID2 GND 6 RED GND 8 Blue GND 10 D GND 12 SDA 14 V Sync Shell GND 2 Y GND 4 Pb GND 6 Pr GND 8 LINE1 10 Line2 Ready 12 SWITCH GND 14 SWITCH Remark For Service Only Middle east NTSC Area JAPAN Only Video Active Off Power C...

Page 9: ...t Dynamic Range Video Output Level Video Output Frequency Response Video Output S N Audio Output Level Audio Output Frequency Response Audio Output S N Audio Output Distortion Video Input Level R G B Video Input Level Component Y PB PR RGB Input Resolution Vertical RGB Input Resolution Horizontal RGB Input Horizontal Frequency RGB Input Frame Rate 0 85 0 4 0 1 40 2 0 85 3 8 40 0 4 0 1 40 0 6 0 6 1...

Page 10: ...adjustment is complete pressing ener key stores and completes the process 2 2 1 Component Mode adjustment Only RT 20LA90 2 2 1 1 Adjustment preparation Execution of RF no signal during Heat Run over 30min The component jack Y Pb Pr of LCD TV is connected to Y Pb Pr Output Signal of Pattern Generator MSPG 925 SERISE 2 2 1 2 Auto Gain Offset adjustment Convert to Component Mode in Input Mode Select ...

Page 11: ...put To check the front AV To move channel up down or to select a function displayed on the screen To adjust the volume or accurately control a specific function To set a specific function or complete setting To move the channel down in the PIP screen To use as a red key in the teletext mode To move the channel in the PIP screen To use as a green key in the teletext mode To switch between the main ...

Page 12: ... present source is TV When Channel Change is set to No Change Impossible Channel Key Numeral Key List Key Q View Key doesn t work and entering Channel Menu in the Main Menu OSD is impossible When Channel Change is set to Yes Change Possible Channel Key Numeral Key List Key Q View Key does work and entering Channel Menu in the Main Menu OSD is possible When Channel Change is set to No Change Imposs...

Page 13: ...Fixed Volume is set to Yes Max Volume item cannot be selected When Max Volume is set volume just goes up to the Max Volume value in On Time Menu 1 6 OSD Display Decide to display OSD or not by setting OSD Display as Yes Mark or No No Mark When OSD Display is set to No No Mark just Channel OSD and STEREO OSD doesn t display 1 7 Remocon Remote Control Operation Decide to operate Remote Control or no...

Page 14: ...rn off TV by Auto Off function of Time Menu This item decide to turn on TV by Auto Off Operation regardless of Auto off function of Time Menu or not by setting as Yes Work or No Do Not Work When Auto Off Operation is set to Yes Work Auto Off Operation work as configuration When Auto Off Operation is set to No Do Not Work Auto Off Operation Do Not work regardless of configuration 1 12 Hotel Mode Op...

Page 15: ...ck short of main B D or Change Lips Change IC1107 IC1104 Change LED Assy Check 15V or 5V of Lips Check Output of IC1107 IC104 Check LED Assy Check P1100 P210 Connector Fail Fail Change Q1100 Check Output of Q1100 Fail Pass Fail Pass Pass Pass A Process ...

Page 16: ...Check inverter Connector or inverter Check input source cable and jack Repeat A PROCESS Fail Change L900 L901 L902 L903 Fail Change IC901 Fail Change inverter connector or inverter Fail Change panel link cable or module Fail Change module Fail Check panel link Cable or module Pass Pass Pass Pass B Process ...

Page 17: ...ss Check the input output of IC1 Check the input output of IC901 Check input source cable and jack Fail Re soldering or Change the defect part Check X11 Fail Re soldering or Change the defect part Check X900 Fail Pass Pass Pass Check the input output of IC800 IC851 Re soldering or Change the defect part Fail Pass ...

Page 18: ...the input output of IC1 Check the input output of IC800 IC851 Check input source cable and jack Fail Fail Fail Fail Re soldering or Change the defect part Chek X11 Fail Re soldering or Change the defect part Check 5V 33V of TU1000 Re soldering or Change the defect part Pass Pass Pass Check the input output of IC901 Fail Re soldering or Change the defect part Check X900 Pass Pass ...

Page 19: ...ut Check the input source Fail Pass Re soldering or Change the defect part Check X11 Check the input output of IC1 Fail Pass Re soldering or Change the defect part Check the input output of IC100 IC101 Fail Pass Change speaker Check the speaker Fail Pass ...

Page 20: ... SUB JA200 POWER AT24C16 IC4 IF SIDE_AV S A W Z1000 H P VIDEO_V PC INPUT FOR SEVICE ISP SCART SIDE L R 1 15V 2 15V 3 GND 4 GND 5 5V 6 5V 7 GND 8 33V 9 CTL 10 EXT 11 BR VIDEO1_L R SIDE_V V L R To AV_JACK B D VIDEO_V YC POWER B D PC AUDIO JA201 M52758FP IC851 VCTi_RGB From JA200 PC_RGB V Y C Tuner TU1000 PC_RGB TTL 1 OUT TTL 2 OUT LVDS 1 OUT AV JACK B D From AMP PC_AUDIO SPEAKER IF SCART RGB R G B S...

Page 21: ...ent to the LCD module as a TTL output VCTi is the main microprocessor that handles video signal processing and sound signal processing It also manages the RF signals received from the tuner The scaler can control timing to fit into the LCD panel and can also control the size and position of the input signal 2 Power Supply Unit The power supply unit provides 15V and 5V DC power to the mainboard The...

Page 22: ...EAKER LOCAL KEY IR_LED 1 5 6 4 2 3 7 8 WIRING DIAGRAM No Part No 1 2 3 4 5 6 7 8 Wiring Part List 6631T25019Y 6631T11017P CMO 6631T11021A LPL 6631T20028G 6631T20033W 6631T25021F 6620K00007C or 6620K00007A 6631T11017R ...

Page 23: ... 23 EXPLODED VIEW 010 050 060 050 070 020 080 110 140 130 090 100 030 120 160 150 040 190 170 200 180 210 ...

Page 24: ...ND IR BOARD ASSY 4951TKS183B METAL ASSEMBLY FRAME RZ 20LA80 90 CMO 4951TKS175B METAL ASSEMBLY FRAME METAL ASSY 20LA70 LPL 4951TKS183D METAL ASSEMBLY FRAME RZ 20LA80 90 CMO CKD 4951TKS175F METAL ASSEMBLY FRAME METAL ASSY 20LA70 LPL CKD 3313TP2029A MAIN TOTAL ASSEMBLY RZ 20LA70 CMO BRAND ML 041B 3313TP2030A MAIN TOTAL ASSEMBLY RZ 20LA70 LPL BRAND ML 041B 6871TPT280A PWB PCB ASSEMBLY POWER RM 20LA77 ...

Page 25: ...RZ 20LA90 ML 041B SUB TOTAL BRAND IR BOARD ASSY 4951TKS175F METAL ASSEMBLY FRAME METAL ASSY 20LA70 LPL CKD 3313TP2027A MAIN TOTAL ASSEMBLY RT 20LA70 LPL BRAND ML 041B 6871TPT280B PWB PCB ASSEMBLY POWER RM 20LA77 POWER TOTAL LIEN CHANG LIPS FOR LPL 6871TST561A PWB PCB ASSEMBLY SUB RM 20LA70 ML041B SUB TOTAL BRAND JACK DVD BOARD ASSY 4951TKK186L METAL ASSEMBLY SHIELD METAL LPL IPS MODULE C SKD 20LA9...

Page 26: ...ON C926 0CH3104K946 100000PF 50V Z F 2012 R TP C927 0CH3104K946 100000PF 50V Z F 2012 R TP C928 0CH3104K946 100000PF 50V Z F 2012 R TP C929 0CH3104K946 100000PF 50V Z F 2012 R TP C930 0CH3104K946 100000PF 50V Z F 2012 R TP C934 0CH3104K946 100000PF 50V Z F 2012 R TP C935 0CH3104K946 100000PF 50V Z F 2012 R TP C936 0CH3104K946 100000PF 50V Z F 2012 R TP C937 0CH3104K946 100000PF 50V Z F 2012 R TP C...

Page 27: ...2 0CK104CK56A 0 1UF 1608 50V 10 R TP X7R C961 0CK104CK56A 0 1UF 1608 50V 10 R TP X7R C121 0CC100CK41A 10PF 1608 50V 5 R TP NP0 C122 0CC100CK41A 10PF 1608 50V 5 R TP NP0 DATE 2004 11 25 S AL LOC NO PART NO DESCRIPTION SPECIFICATION C43 0CC102CK41A 1000PF 1608 50V 5 R TP NP0 C47 0CC220CK41A 22PF 1608 50V 5 R TP NP0 C48 0CC220CK41A 22PF 1608 50V 5 R TP NP0 C53 0CC102CK41A 1000PF 1608 50V 5 R TP NP0 C...

Page 28: ...L15 0LC1032101A 10UH 10 3216 R TC FI C3216 L2 0LC1032101A 10UH 10 3216 R TC FI C3216 L8 0LC1032101A 10UH 10 3216 R TC FI C3216 L888 0LC0233002A 3 3UH CERATECH R TP L889 0LC0233002A 3 3UH CERATECH R TP L890 0LC0233002A 3 3UH CERATECH R TP DATE 2004 11 25 S AL LOC NO PART NO DESCRIPTION SPECIFICATION IC1107 0TF492509AA SI4925DY TP TEMIC 30V 6 1A Q1 0TR387500AA CHIP 2SC3875S ALY BK KEC Q603 0TR387500...

Page 29: ...M 1 10 W 5 1608 R TP R240 0RJ1000D677 100 OHM 1 10 W 5 1608 R TP R25 0RJ1000D677 100 OHM 1 10 W 5 1608 R TP DATE 2004 11 25 S AL LOC NO PART NO DESCRIPTION SPECIFICATION R28 0RJ0000D677 0 OHM 1 10 W 5 1608 R TP R29 0RJ0000D677 0 OHM 1 10 W 5 1608 R TP R3 0RJ4700D677 470 OHM 1 10 W 5 1608 R TP R34 0RJ0000D677 0 OHM 1 10 W 5 1608 R TP R4 0RJ1500D677 150 OHM 1 10 W 5 1608 R TP R41 0RJ1000D677 100 OHM...

Page 30: ...L200000CA SAM5670 DL 2LRG BK Y GREEN C1201 0CH6221K416 220PF 50V J NP0 2012 R TP C1202 0CH6101K416 100PF 50V J NP0 2012 R TP C1207 0CH6471K416 470F 50V J NP0 2012 R TP C1208 0CH6471K416 470F 50V J NP0 2012 R TP C1215 0CH3103K516 10000PF 50V 10 B Y5P 2012 C1216 0CH3103K516 10000PF 50V 10 B Y5P 2012 C1221 0CH6331K416 330PF 50V J NP0 2012 R TP C1223 0CH6471K416 470F 50V J NP0 2012 R TP C1224 0CH6471K...

Page 31: ... 0RH1001D622 1K OHM 1 10 W 2012 5 00 D R1222 0RH1001D622 1K OHM 1 10 W 2012 5 00 D R1226 0RH0472D622 47 1 10W 5 D R TP R1227 0RH0752D622 75 1 10W 5 D R TP R1228 0RH0752D622 75 1 10W 5 D R TP R1229 0RH0752D622 75 1 10W 5 D R TP ZD1210 0DZ620009HB UDZ S 6 2B TP ROHM SOD323 20 ZD1211 0DZ620009HB UDZ S 6 2B TP ROHM SOD323 20 ZD1215 0DZ620009HB UDZ S 6 2B TP ROHM SOD323 20 ZD1216 0DZ620009HB UDZ S 6 2B...

Page 32: ...CIFICATION C930 0CH3104K946 100000PF 50V Z F 2012 R TP C934 0CH3104K946 100000PF 50V Z F 2012 R TP C935 0CH3104K946 100000PF 50V Z F 2012 R TP C936 0CH3104K946 100000PF 50V Z F 2012 R TP C937 0CH3104K946 100000PF 50V Z F 2012 R TP C938 0CH3104K946 100000PF 50V Z F 2012 R TP C939 0CH3104K946 100000PF 50V Z F 2012 R TP C940 0CH3104K946 100000PF 50V Z F 2012 R TP C943 0CH3104K946 100000PF 50V Z F 201...

Page 33: ... R TP X7R C921 0CK104CK56A 0 1UF 1608 50V 10 R TP X7R C922 0CK104CK56A 0 1UF 1608 50V 10 R TP X7R C961 0CK104CK56A 0 1UF 1608 50V 10 R TP X7R C121 0CC100CK41A 10PF 1608 50V 5 R TP NP0 C122 0CC100CK41A 10PF 1608 50V 5 R TP NP0 DATE 2004 11 25 S AL LOC NO PART NO DESCRIPTION SPECIFICATION C43 0CC102CK41A 1000PF 1608 50V 5 R TP NP0 C47 0CC220CK41A 22PF 1608 50V 5 R TP NP0 C48 0CC220CK41A 22PF 1608 50...

Page 34: ...EMIC 30V 6 1A IC1107 0TF492509AA SI4925DY TP TEMIC 30V 6 1A Q1150 0TR322809AB KTC3228 Y KTC2383 TP KEC TO Q1 0TR387500AA CHIP 2SC3875S ALY BK KEC Q603 0TR387500AA CHIP 2SC3875S ALY BK KEC Q900 0TR387500AA CHIP 2SC3875S ALY BK KEC DATE 2004 11 25 S AL LOC NO PART NO DESCRIPTION SPECIFICATION Q100 0TR387500AA CHIP 2SC3875S ALY BK KEC Q1000 0TR388109AA KTC3881 CHIP TP KEC Q101 0TR150400BA CHIP 2SA150...

Page 35: ... R TP R51 0RJ1000D677 100 OHM 1 10 W 5 1608 R TP R52 0RJ1000D677 100 OHM 1 10 W 5 1608 R TP DATE 2004 11 25 S AL LOC NO PART NO DESCRIPTION SPECIFICATION R53 0RJ1500D677 150 OHM 1 10 W 5 1608 R TP R54 0RJ1000D677 100 OHM 1 10 W 5 1608 R TP R55 0RJ1500D677 150 OHM 1 10 W 5 1608 R TP R56 0RJ1000D677 100 OHM 1 10 W 5 1608 R TP R58 0RJ1000D677 100 OHM 1 10 W 5 1608 R TP R60 0RJ1000D677 100 OHM 1 10 W ...

Page 36: ...2 R TP C1223 0CH6471K416 470F 50V J NP0 2012 R TP C1224 0CH6471K416 470F 50V J NP0 2012 R TP L1200 0RH0752D622 75 1 10W 5 D R TP L1202 0RH0000D622 0 OHM 1 10 W 2012 5 00 D L1203 0RH0000D622 0 OHM 1 10 W 2012 5 00 D L1206 6210TCE001A HB 1S2012 080JT CERATEC 2012 L1207 6210TCE001A HB 1S2012 080JT CERATEC 2012 L1208 6210TCE001A HB 1S2012 080JT CERATEC 2012 DATE 2004 11 25 S AL LOC NO PART NO DESCRIPT...

Page 37: ...Date 2004 05 07 P No 3854TN1001A ...

Page 38: ...Date 2004 05 07 P No 3854TN1001A ...

Page 39: ...NOV 2004 Printed in Korea P NO 3828TSL108Q ...

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