background image

SERVICE MANUAL

This Service Manual is for the 
LT850-M19 (A0CN0EP) / LT851-M19 (A0CN1EP) model.
For the LT850-M19 (A0CN0EP) / LT851-M19 (A0CN1EP) model, the letter 
(A0CN0EP) / (A0CN1EP) is printed on the Serial Number Label on the back 
of the unit. Refer to the Serial Number Label below.

Serial No. Label

Serial No. Label

"A0CN0EP"

"A0CN1EP"

19

 COLOR LCD TELEVISION

LT850-M19 

LT851-M19

Summary of Contents for LT850-M19 - SERVICE

Page 1: ...EP model For the LT850 M19 A0CN0EP LT851 M19 A0CN1EP model the letter A0CN0EP A0CN1EP is printed on the Serial Number Label on the back of the unit Refer to the Serial Number Label below Serial No Lab...

Page 2: ...ze the LCD Television 6 1 Firmware Renewal Mode 7 1 Troubleshooting 8 1 Block Diagrams 9 1 Schematic Diagrams CBA and Test Points 10 1 Waveforms 11 1 Wiring Diagram 12 1 Exploded View 13 1 Mechanical...

Page 3: ...nit Nominal Limit 1 RECEIVED FREQ RANGE 60dBm 45ch 1 2 kHz kHz 1000 900 500 167 2 INPUT DYNAMIC RANGE mix max c 1 VHF HIGH 8ch UHF 45ch dBuV dBuV 25 101 25 101 28 98 29 98 d 2 VHF HIGH 8ch UHF 45ch dB...

Page 4: ...ghtly below these specifications Limit specifications represent the absolute worst condition that still might be considered acceptable In no case should a unit fail to meet limit specifications Descri...

Page 5: ...terminal screw and if applicable to the coaxial connector If the measured resistance is less than 1 0 megohm or greater than 5 2 megohm an abnormality exists that must be corrected before the instrum...

Page 6: ...near thermally hot parts be sure that leads and components do not touch thermally hot parts c the AC supply d high voltage and e antenna wiring Always inspect in all areas for pinched out of place or...

Page 7: ...PVC tubing 3 Spacers 4 Insulators for transistors E When replacing AC primary side components transformers power cord etc wrap ends of wires securely about the terminals before soldering F Observe tha...

Page 8: ...and externally exposed accessible parts RF terminals an tenna terminals video and audio input and output ter minals microphone jacks earphone jacks etc Measuring Method Power ON Insert load Z between...

Page 9: ...the flat pack IC is fixed with glue to the CBA when removing entire flat pack IC first apply soldering iron to center of the flat pack IC and heat up Then remove glue will be melted Fig S 1 6 4 Relea...

Page 10: ...ins of the flat pack IC you can remove it easily Fig S 1 3 2 Affix the wire to a workbench or solid mounting point as shown in Fig S 1 5 3 While heating the pins using a fine tip soldering iron or hot...

Page 11: ...occur due to a potential difference caused by electrostatic charge during unpacking or repair work 1 Ground for Human Body Be sure to wear a grounding band 1 M that is properly grounded to remove any...

Page 12: ...g 2 S 2 two Screws S 2 2 L 2 two Locking Tabs L 2 5 Refer to the following Reference Notes in the Table Step Loc No Part Removal Fig No Remove Unhook Unlock Release Unplug Unclamp Desolder Note 1 Sta...

Page 13: ...4 2 A0CN0DC 2 Rear Cabinet 1 Stand Assembly S 3 S 2 S 2 S 2 S 2 S 2 S 4 S 4 S 1 Fig D1...

Page 14: ...nd Holder 7 Digital Main CBA Unit 9 LCD Module Assembly 10 Speaker 10 Speaker 11 Junction CBA 12 Function CBA 13 Front Cabinet S 8 S 10 S 10 S 6 S 6 S 6 S 12 S 11 S 5 S 8 S 13 S 13 S 9 H 1 Speaker Hol...

Page 15: ...1 CN301 Digital Main CBA Unit CN801 CN152 AC CORD CN3704 CN3401 CN3702 CN3703 CN3701 CN3901 CN302 CN303 CN404 CN401 CN802 CN1002 CN101A Junction CBA Function CBA CN101 CN101B To Speaker To LCD Module...

Page 16: ...stments unless the proper equipment is available Test Equipment Required 1 NTSC Pattern Generator Color Bar W White Window Red Color Dot Pattern Gray Scale Monoscope Multi Burst 2 Remote control unit...

Page 17: ...he LCD Panel surface 3 Enter the Service mode 4 To enter the VCOM 2 adjustment mode press 3 button on the remote control unit To enter the VCOM 1 adjustment mode press 2 button on the remote control u...

Page 18: ...de 5 CUTOFF Press 1 button to select COR for Red Cutoff adjustment Press 3 button to select COB for Blue Cutoff adjustment DRIVE Press 4 button to select DR for Red Drive adjustment Press 6 button to...

Page 19: ...the service mode Refer to page 5 1 To cancel the service mode press button on the remote control unit 3 Press button on the remote control unit to initialize the LCD television 4 INITIALIZED will app...

Page 20: ...h digit of the file name indicate the size of TV If the size of your TV and the file name were not the same you must change the file name Update procedure 1 Plug in the AC power cord 2 Press button on...

Page 21: ...d service it if defective Check the presence that the primary component is leaking or shorted and service it if defective Check the presence that the rectifying diode or circuit is shorted in each rec...

Page 22: ...05 Check D634 and their periphery circuit and service it if defective Replace Q605 Is approximately 7 5V voltage supplied to the collector of Q616 Replace Q616 No AL 33V is not outputted FLOW CHART NO...

Page 23: ...11V voltage supplied to the anode of D613 Is approximately 10V voltage supplied to the base of Q611 Yes Is approximately 14V voltage supplied to the base of Q615 No Check D664 and their periphery circ...

Page 24: ...ervice it if defective No P ON 11V is not output FLOW CHART NO 14 Yes No Is approximately 15V voltage supplied to the collector of Q609 Is approximately 12V voltage supplied to the base of Q609 No Yes...

Page 25: ...signal line and service it if defective Check the composite video signal line and service it if defective Check the component video Y Pb Pr signal line and service it if defective Check the line betw...

Page 26: ...is not outputted normally Audio input terminals FLOW CHART NO 21 Check the line between Pin 16 18 of CN303 and Pin 4 5 of TU10 and TU10 Tuner Unit and service it if defective Are the DIF signals outpu...

Page 27: ...P ON H1 PROTECT1 P ON H2 P ON H1 AH2 JUNCTION CBA CN101 KEY IN1 6 6 CN152 CN303 CN3703 AH27 BACKLIGHT ADJ IC3102 SERIAL FLASH MEMORY CLOCK DATA IN D11 B10 6 5 E23 TUNER CLK TUNER DATA CN303 CN3703 CN3...

Page 28: ...COM VIDEO Pb IN 6 6 COM VIDEO Pr IN 8 8 VIDEO OUT 15 BUFFER Q10 TU CVBS 29 29 S SW 1 1 TU CVBS TU10 DIF OUT2 4 DIF OUT1 5 TUNER UNIT IF AGC 6 CN303 CN3703 DIF OUT2 16 16 IF AGC 20 20 DIF OUT1 18 18 V...

Page 29: ...IGNAL PROCESS BLOCK DIAGRAM DIGITAL MAIN CBA UNIT SIF OUT TU10 TUNER UNIT 14 7 1 6 2 SIF 26 26 HEADPHONE L 3 3 HEADPHONE R 4 4 HEADPHONE DET 2 2 CN3703 CN303 AMP L OUT 10 10 AMP R OUT 8 8 AUDIO MUTE 1...

Page 30: ...TMDS D0 TMDS D1 TMDS D1 TMDS D2 TMDS D2 TMDS CLOCK TMDS CLOCK SDA SCL F2 F1 G2 G1 H2 H1 E2 E1 AG10 AJ8 B1 B2 C1 C2 D1 D2 A1 A2 AF10 AE11 TMDS CLOCK TMDS CLOCK DEMODULATOR MPEG DECODER DEMODU ADC DAC...

Page 31: ...Q1014 Q1005 Q1004 Q1006 Q1008 Q1012 Q1002 Q1011 Q1023 Q1024 DRIVE Q1010 Q1017 Q1018 DRIVE OSC PWM CONTROL LOGIC VCC DTC CURRENT CONTROL SWITCH Q1009 OVER VOLTAGE PROTECTOR Q1015 OVER VOLTAGE PROTECTOR...

Page 32: ...y circuit to fail HOT COLD MAIN CBA HOT CIRCUIT BE CAREFUL Q602 SWITCHING CONTROL 1 4 3 2 IC605 T601 5 LINE FILTER L601 AC601 AC CORD BRIDGE RECTIFIER D602 D604 D605 D607 3 4 19 18 17 16 15 14 13 12 7...

Page 33: ...itute replacement parts that do not have the same safety characteristics as specified in the parts list may create shock fire or other hazards Notes 1 Do not use the part number shown on these drawing...

Page 34: ...ed 2 To maintain original function and reliability of repaired units use only original replacement parts which are listed with their part numbers in the parts list section of the service manual 4 Volt...

Page 35: ...table power supply circuit is used in this unit If Main Fuse F601 is blown check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power...

Page 36: ...10 4 A0CN0SCM2 Main 2 Schematic Diagram...

Page 37: ...10 5 A0CN0SCM3 Main 3 Schematic Diagram...

Page 38: ...10 6 A0CN0SCM4 Main 4 Schematic Diagram...

Page 39: ...10 7 A0CN0SCF Function Junction Schematic Diagram...

Page 40: ...Main 1 Schematic Diagram The order of pins shown in this diagram is different from that of actual IC3301 IC3301 is divided into six and shown as IC3301 1 7 IC3301 7 7 in this Digital Main Schematic D...

Page 41: ...Main 2 Schematic Diagram The order of pins shown in this diagram is different from that of actual IC3301 IC3301 is divided into six and shown as IC3301 1 7 IC3301 7 7 in this Digital Main Schematic D...

Page 42: ...l Main 3 Schematic Diagram The order of pins shown in this diagram is different from that of actual IC3301 IC3301 is divided into six and shown as IC3301 1 7 IC3301 7 7 in this Digital Main Schematic...

Page 43: ...l Main 4 Schematic Diagram The order of pins shown in this diagram is different from that of actual IC3301 IC3301 is divided into six and shown as IC3301 1 7 IC3301 7 7 in this Digital Main Schematic...

Page 44: ...l Main 5 Schematic Diagram The order of pins shown in this diagram is different from that of actual IC3301 IC3301 is divided into six and shown as IC3301 1 7 IC3301 7 7 in this Digital Main Schematic...

Page 45: ...l Main 6 Schematic Diagram The order of pins shown in this diagram is different from that of actual IC3301 IC3301 is divided into six and shown as IC3301 1 7 IC3301 7 7 in this Digital Main Schematic...

Page 46: ...l Main 7 Schematic Diagram The order of pins shown in this diagram is different from that of actual IC3301 IC3301 is divided into six and shown as IC3301 1 7 IC3301 7 7 in this Digital Main Schematic...

Page 47: ...30 C301 C1055 J255 D1031 J256 D1033 J257 R1030 D1034 C1058 J258 R1031 D1035 C1059 J259 R1032 D1036 R1033 D1038 R1034 D1039 J260 J261 J262 R157 D1040 J264 J265 D1041 C312 J267 J268 R11 D1045 J269 R12 R...

Page 48: ...ALL 3 3V ALL 3 3V PON 11V PON 11V PON 11V PON 11V A MUTE SCART OUT SEL VDACOUT1 AMP R AMP L 33V GND GND GND PCB STUD PCB STUD PROTECT 1 UVP 2 UVP 1 BL ON 7 5V BL ON 7 5V BL ON 7 5V PROTECT 3 P ON OFF...

Page 49: ...tic Diagram S VIDEO Y S VIDEO Y 0 2V 0 2V 20 20 s S VIDEO C S VIDEO C 0 2V 0 2V 20 20 s VIDEO Y VIDEO Y 0 2V 0 2V 20 20 s 20 20 s VIDEO Pr VIDEO Pr 0 2V 0 2V 20 20 s VIDEO Pb VIDEO Pb 0 2V 0 2V 20 20...

Page 50: ...Pin 26 of CN404 AUDIO L AUDIO L 0 5V 0 5V 0 5m 0 5ms WF7 Pin 22 of CN401 20 20 s VIDEO G VIDEO G 0 5V 0 5V 20 20 s VIDEO R VIDEO R 0 5V 0 5V 20 20 s Input PAL Color Bar Signal with 1kHz Audio Signal W...

Page 51: ...4 6 8 10 14 12 18 16 11 13 15 1 5 3 9 7 2 4 6 8 10 11 17 19 23 21 20 25 21 23 17 19 24 22 20 18 16 12 14 8 10 15 13 11 9 7 3 5 6 22 RESET 24 2 P ON H2 25 1 P ON H1 P ON 11V GND GND GND AL 3 3V P ON 3...

Page 52: ...it AC601 Function CBA Junction CBA Main CBA Stand Assembly L17 B13 B12 B12 B21 L9 L1 L1 L1 L1 L3 L1 L1 L5 A4 B3 L3 B18 A16 L19 L3 B1 L3 L3 B9 L11 L19 L3 B3 L2 L2 L3 L3 L8 L1 L8 B8 B8 A5 A1 A3 L3 L1 L9...

Page 53: ...13 2 A0CN0PEX Packing S4 S5 S3 Tape Packing Tape Packing Tape Packing Tape S6 L17 X1 Some Ref Numbers are not in sequence Stand Assembly X3 X4 FRONT FRONT X2 1 X2 2 S2 S1 Tape...

Page 54: ...SSEMBLY 29PIN FFC 29PIN 50MM WX1A94F0 101 CL401 WIRE ASSEMBLY 29PIN FFC 29PIN 50MM WX1A94F0 101 CL404 WIRE ASSEMBLY 29PIN FFC 29PIN 50MM WX1A94F0 101 CL801 WIRE ASSEMBLY 2PIN WX1A93N0 001 WX1A93N0 001...

Page 55: ...1000pF 50V or CHD1JJ3CH102 CAP CHIP 1608 J C0G 0 001 F 50V CHD102EYA030 C154 CHIP CERAMIC CAP 1608 F Z 0 1 F 25V CHD1EZ30F104 C155 CHIP CERAMIC CAP 1608 F Z 0 1 F 50V or CHD1JZ30F104 CAP CHIP 1608 Z Y...

Page 56: ...93SER02 CAP POLYESTER FILM 0 039 F 100V J PCMT or CTA393PKR003 Ref No Mark Description Part No POLYESTER FILM CAP 0 039 F 100V J CMB393EUR001 C611 SAFTY CAP 3300pF 250V or CCN2EMA0E332 SAFTY CAP 3300p...

Page 57: ...F 50V CHD103EYA032 Ref No Mark Description Part No C1004 CHIP CERAMIC CAP 1608 B K 0 01 F 50V or CHD1JK30B103 CAP CHIP 1608 K X7R 0 01 F 50V CHD103EYA032 C1005 POLYESTER FILM CAP PB FREE 0 022 F 100V...

Page 58: ...ECTOR PRINT OSU KW05 120 02 00 J30502KET001 DIODES D151 SWITCHING DIODE 1SS133 T 77 or QDTZ001SS133 DIODE SWITCHING HSS4148TE E or QDTZ0HSS4148 DIODE SWITCHING 1N4148 F0021 NDTZ01N4148F D302 WIRE CP S...

Page 59: ...0TAUK01 IC SHUNT REGULATOR AS431BZTR E1 NSZBA0TBCD01 Ref No Mark Description Part No D635 SWITCHING DIODE 1SS133 T 77 or QDTZ001SS133 DIODE SWITCHING HSS4148TE E or QDTZ0HSS4148 DIODE SWITCHING 1N4148...

Page 60: ...CHING DIODE 1SS133 T 77 or QDTZ001SS133 DIODE SWITCHING HSS4148TE E or QDTZ0HSS4148 DIODE SWITCHING 1N4148 F0021 NDTZ01N4148F D1025 SWITCHING DIODE 1SS133 T 77 or QDTZ001SS133 DIODE SWITCHING HSS4148T...

Page 61: ...NPN TRANSISTOR 2SC5343G AT or NQSG02SC5343 NPN TRANSISTOR 2SC5343MG AT or NQSG2SC5343M Ref No Mark Description Part No NPN TRANSISTOR 2SC5343M Y NQSY2SC5343M Q608 TRANSISTOR KTC3198 Y AT P or NQSYKTC...

Page 62: ...1267 GR AT P or NQS1KTA1267P TRANSISTOR KTA 1266 GR AT P or NQS4KTA1266P Ref No Mark Description Part No TRANSISTOR 2SA1015 Y TE2 F T or QQSY2SA1015F TRANSISTOR 2SA1015 GR TE2 F T or QQS12SA1015F PNP...

Page 63: ...WIRE CP STP S 0 50 or XZ40F0REN001 WIRE CP STP S 0 60 or XZ40F0REN002 WIRE CP 6113 05603 0220 or XZ40F0SHG001 WIRE CP CP0 56 XZ40F0XRC001 Ref No Mark Description Part No R12 RES CARBON FILM T 1 4W J...

Page 64: ...n Part No R455 RES CARBON FILM T 1 4W J 15k or RCX4153T1001 RES CARBON FILM 1 4W J 15k RCX4153FS002 R456 RES CARBON FILM T 1 4W J 15k or RCX4153T1001 RES CARBON FILM 1 4W J 15k RCX4153FS002 R457 RES C...

Page 65: ...Z0101 RES CHIP 1608 1 10W J 100 RRXA101YF002 R649 CHIP RES 1 10W J 4 7k or RRXAJR5Z0472 Ref No Mark Description Part No RES CHIP 1608 1 10W J 4 7k RRXA472YF002 R650 CHIP RES 1 10W J 100k or RRXAJR5Z01...

Page 66: ...2k RCX4222FS002 R1004 CHIP RES 1 10W J 10k or RRXAJR5Z0103 Ref No Mark Description Part No RES CHIP 1608 1 10W J 10k RRXA103YF002 R1005 CHIP RES 1 10W J 22k or RRXAJR5Z0223 RES CHIP 1608 1 10W J 22k R...

Page 67: ...F 68k or RRXAFR5H6802 CHIP RES 1 10W F 68k or RRXAFR5Z6802 RES CHIP 1608 1 10W F 68 0k RTW6802YF002 Ref No Mark Description Part No R1083 CHIP RES 1 10W F 1M or RRXAFR5H1004 CHIP RES 1 10W F 1M or RR...

Page 68: ...RED 01 MTJ 032 04A 75 FE JYRJ010LY031 Ref No Mark Description Part No JK413 JACK RGB PCB S 01 RGB 11HS JXGJ21YUQ001 JS611 CHIP RES 1608 1 10W 0 or RRXAZR5Z0000 RES CHIP 1608 1 10W J 0 RRXA000YF002 L1...

Page 69: ...10 or SST0101AL049 TACT SWITCH KSMC632A SST0101HH025 MISCELLANEOUS JS901 CHIP RES 1608 1 10W 0 or RRXAZR5Z0000 RES CHIP 1608 1 10W J 0 RRXA000YF002 JS902 CHIP RES 1608 1 10W 0 or RRXAZR5Z0000 RES CHIP...

Page 70: ...LT850 M19 LT851 M19 A0CN0EP A0CN1EP 2010 05 25...

Reviews: