Samsung LT20A350 Service Manual Download

Page: 45 / 76

4-16

4. Troubleshooting

4-1-7. No Video (Video CVBS)

Symptom

Audio is normal but no picture is displayed on the screen.

Major

checkpoints

Check the Video CVBS source

Check the Main Chipset.

This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.

Diagnostics

MAIN BOARD

SMPS BOARD

Does the CVBS data appear at

PIN - COMP1_Y_CVBS, COMP2_Y_CVBS?

Does the digital data appear at

TP-, E_TXCLK- ,

, O_TXCLK-?

Yes

Check a set in the 'Stand-by mode'.

Input the video source properly.

Please, Contact Tech support.

Check CN503.

Change the Main Assy.

Check IC1111 (X5).

Change the Main Assy.

Power indicator LED is off.

Lamp(Backlight) on, no video ?

Check the video source and

check the connection of video cable?

Check the LVDS cable?

Check the T-Con B'd?

Replace the LCD panel?

Caution

Make sure to disconnect the power before working on the IP board.

Summary of Contents for LT20A350

Page 1: ...Contents 1 Precautions 2 Product specifications 3 Disassembly and Reassembly 4 Troubleshooting 5 Wiring Diagram LCD TV Monitor TA350 TA550 Chassis Model WDS2 LT20A350 LT22A350 LT23A350 LT24A350 WDS4 L...

Page 2: ...ures explanation 2 10 3 Disassembly and Reassembly 3 1 3 1 Disassembly and Reassembly 3 1 4 Troubleshooting 4 1 4 1 Troubleshooting 4 1 4 2 Alignments and Adjustments 4 25 4 3 Factory Mode Adjustments...

Page 3: ...nual is a property of Samsung Electronics Co Ltd Any unauthorized use of Manual can be punished under applicable International and or domestic law 2011 Samsung Electronics Co Ltd All rights reserved P...

Page 4: ...ican National Standards Institute ANSI C101 1 Leakage Current for Appliances and Underwriters Laboratories UL Publication UL1410 59 7 4 With the unit completely reassembled plug the AC line cord direc...

Page 5: ...strument s ground lead last 1 3 Electrostatically Sensitive Devices ESD Precautions Some semiconductor solid state devices can be easily damaged by static electricity Such components are commonly call...

Page 6: ...it from being exposed to moisture Otherwise it may cause a fire or electric shock 5 Make sure to turn the power off and unplug the power cord from the outlet before repositioning the product Also che...

Page 7: ...voltage Frequency AC 100V 240V 50 60 Hz Power Consumption Under 40W Under 0 3W Stand by Dimensions Set W x D x H 19 2 x 8 4 x 15 2 inches 487 8 x 214 2 x 387 3 mm _with stand 19 2 x 1 4 x 12 1 inches...

Page 8: ...TA350 20 6 x 9 4 x 16 3 inchs 523 9 x 239 2 x 413 5 mm _with stand 20 6 x 1 4 x 12 9 inchs 523 9 x 35 7 x 327 7 mm _without stand TA550 20 7 x 8 7 x 16 3 inchs 525 5 x 220 6 x 414 4 mm _with stand 20...

Page 9: ...H TA350 21 9 x 9 4 x 17 0 inchs 555 7 x 239 2 x 431 9 mm _with stand 21 9 x 1 2 x 13 6 inchs 555 7 x 31 6 x 345 6 mm _without stand TA550 20 0 x 8 7 x 17 1 inchs 559 1 x 220 6 x 433 8 mm _with stand...

Page 10: ...TA350 22 8 x 9 4 x 17 5 inchs 578 6 x 239 2 x 444 6 mm _with stand 22 8 x 1 3 x 14 1 inchs 578 6 x 33 2 x 359 1 mm _without stand TA550 22 9 x 8 0 x 17 6 inchs 581 4 x 220 6 x 446 1 mm _with stand 22...

Page 11: ...ency AC 100V 240V 50 60 Hz Power Consumption Under 65W Under 0 3W Stand by Dimensions Set W x D x H 25 5 x 9 3 x 19 1 inches 648 1 x 235 x 485 7 mm _with stand 25 5 x 1 3 x 15 7 inches 648 1 x 31 8 x...

Page 12: ...2 Type 19A6TH0E 19L6TH0E 20A6TH0E 22D6TF0E 22L6TF0E 23A6TF0E 24L6TF0E 27A6TF0E 20A6TH0E 22L6TF0E 23A6TF0E 24L6TF0E 3 Local set EU EU_ITALY EU_GER EU_FRANCE EU_BENELUX EU_UK EU_ARMENIA NORDIG AD_AU AD...

Page 13: ...6TF0E 23A6TF0E 24L6TF0E 27A6TFOE 3 Local set EU EU_ITALY EU_GER EU_FRANCE EU_BENELUX EU_UK EU_ARMENIA NORDIG AD_AU AD_NZ AD_SINGAPOL CIS_RUSIA CIS_UKRINA CIS_KAZAKH EU_TURKEY EU_AFRICA EU_MOROCO EA_VI...

Page 14: ...3 000525 Stand Base TA350 20 BN96 16602C 22 23 24 BN96 16601C TA550 22 23 24 BN96 17582B 27 BN96 17132E Stand Body TA350 20 BN96 17598B 22 BN96 17604B 23 24 BN96 17599B TA550 22 BN96 17583B 23 24 BN96...

Page 15: ...Samsung Electronics Service center SCART Gender ALL BN39 01154F CI Card Gender ALL 3709 001663 User Manual ALL BN46 00077A Quick Setup Guide ALL BN68 03605 Cleaning Cloth ALL BN63 01798B Warranty Car...

Page 16: ...d status of the Anynet devices connected to the TV Anynet Menu Description View TV Changes Anynet mode to TV broadcast mode Device List Shows the Anynet device list device_name MENU Shows the connecte...

Page 17: ...cording device_name N Pressing the REC button will record whatever you are currently watching If you are watching video from another device the video from the device is recorded N Before recording che...

Page 18: ...nu Press the SOURCE button on the TV remote control and select a device other than Anynet devices Press CH CH LIST PRE CH and FAV CH to change the TV mode Note that the channel button operates only wh...

Page 19: ...please back up your files to prevent them from damage or loss of data SAMSUNG is not responsible for any data file damage or data loss USB HDD is not supported Do not disconnect the USB device while...

Page 20: ...to the desired file using the buttons and then press the ENTERE or Play button The file is played My Contents screen may differ depending on the way to enter the screen Information You can ascertain t...

Page 21: ...bps Audio Codec avi mkv AVI MKV Divx 3 11 4 x 5 1 6 0 1920 x 1080 6 30 8 MP3 AC3 LPCM ADPCM DTS Core XviD 1920 x 1080 6 30 8 H 264 BP MP HP 1920 x 1080 6 30 25 MPEG4 SP ASP 1920 x 1080 6 30 8 Motion J...

Page 22: ...e rate above the compatible Frame sec listed in the table above If the Index Table is in error the Seek Jump function is not supported The videos over 10Mbps bit rate may be interrupted Video Decoder...

Page 23: ...ns are not displayed even if they are saved on the same USB device N If the sound is abnormal when playing MP3 files adjust the Equalizer in the Sound menu An over modulated MP3 file may cause a sound...

Page 24: ...is displayed press the ENTERE button to start the slide show During the slide show all files in the file list will be displayed in order N When you press the Play button in the file list slide show w...

Page 25: ...tting c c c Subtitle Language You can enjoy video in one of supported languages as required The function is only enabled when stream type files which support multiple audio formats are played c Subtit...

Page 26: ...s Monitor contains electrostatically sensitive devices Use caution when handling these components 3 1 Disassembly and Reassembly Cautions 1 Disconnect the Monitor from the power source before disassem...

Page 27: ...2 3 Disassembly and Reassembly Description Picture Description Screws 2 Remove the 2 screws of the set Remove stand 6001 002621 3 Remove the 6 screws of rear cover 6003 001086 4 Lift up the rear cove...

Page 28: ...ription Screws 5 Remove the left and right speaker 6 Remove the 4 screws of main board Remove the 3 screws of SMPS board 20 4 screws Remove bracket link 6003 000115 7 Lift up the panel Reassembly proc...

Page 29: ...3 4 3 Disassembly and Reassembly Screw Size Code No A mm B mm C mm 6003 001003 8 0 0 2 8 0 0 6 3 83 3 98 6003 001086 6 3 0 5 12 0 0 8 2 85 2 95 6003 000115 6 3 0 5 6 0 0 8 2 85 2 95...

Page 30: ...k 1 Check the various cable connections first Check to see if any cables are damaged or burnt Check to see if there is a disconnected or loose cable connection Check to see if the cables are connected...

Page 31: ...k the following Check the internal cable connection status inside the unit Check the fuses of each part Check the output voltage of SMPS Replace the Main Board Diagnostics MAIN BOARD SMPS BOARD Yes Ch...

Page 32: ...Pin 1 5 of Panel Change the T con b d Check a other function No picture part Replace a LCD Panel No No Does proper DC B13V appear at F1 of T con b d A power is supplied to set Caution Make sure to dis...

Page 33: ...at PIN R G B HS VS R G B H V Does the digital data appear at TP E_TXCLK E_TXCLK Yes Yes Yes Yes Check a set in the Stand by mode or DPMS mode Input the analog PC signal properly Check CN401 PC cable C...

Page 34: ...4 5 4 Troubleshooting Main Board_Top Main Board_Bottom...

Page 35: ...4 6 4 Troubleshooting WAVEFORMS 1 PC input V sink H sink R G B 2 LVDS output...

Page 36: ...4 Pin 12 7 HDMI2 CN602 Pin 12 7 HDMI3 CN603 Pin 12 7 HDMI4 HDMI RX_Clk RX_Data Does the digital data appear at TP E_TXCLK E_TXCLK Yes Yes Yes Yes Check a set in the Stand by mode Input the HDMI signal...

Page 37: ...4 8 4 Troubleshooting Main Board_Top Main Board_Bottom...

Page 38: ...4 9 4 Troubleshooting WAVEFORMS 3 HDMI input RX_Data RX_Clk 2 LVDS output...

Page 39: ...V_TU_PW B33V_TU_PW appear at 3 5 Pin of Tuner Does the digital data appear at TP E_TXCLK E_TXCLK O_TXCLK O_TXCLK Yes Yes Yes Yes Check a set in the Stand by mode Input the RF source properly Please Co...

Page 40: ...4 11 4 Troubleshooting Main Board_Top Main Board_Bottom...

Page 41: ...4 12 4 Troubleshooting WAVEFORMS 2 LVDS output...

Page 42: ...he signal strength in Self Diagnosis menu Strength is enough Does the digital data appear at TP E_TXCLK E_TXCLK O_TXCLK O_TXCLK Yes Yes Yes Yes Yes Check a set in the Stand by mode Input the RF source...

Page 43: ...4 14 4 Troubleshooting Main Board_Top Main Board_Bottom...

Page 44: ...4 15 4 Troubleshooting WAVEFORMS 2 LVDS output...

Page 45: ...COMP1_Y_CVBS COMP2_Y_CVBS Does the digital data appear at TP E_TXCLK E_TXCLK O_TXCLK O_TXCLK Yes Yes Yes Yes Check a set in the Stand by mode Input the video source properly Please Contact Tech suppor...

Page 46: ...4 17 4 Troubleshooting Main Board_Bottom Main Board_Bottom...

Page 47: ...4 18 4 Troubleshooting WAVEFORMS 4 CVBS OUT Grey Bar 2 LVDS output...

Page 48: ...COMP2_PB COMP2_PR Does the digital data appear at TP E_TXCLK E_TXCLK O_TXCLK O_TXCLK Yes Yes Yes Yes Check a set in the Stand by mode Input the component source properly Please Contact Tech support C...

Page 49: ...4 20 4 Troubleshooting Main Board_Bottom Main Board_Bottom...

Page 50: ...4 21 4 Troubleshooting WAVEFORMS 5 Compnent_Y Gray scale Pb Pr Color bar 2 LVDS output...

Page 51: ...2VS_PW Does the sound data appear at PIN COMP2_SR_IN COMP2_SL_IN VIA PC_DVI_SR_IN PC_DVI_SL_IN PC DVI Does the sound data appear at TP SPK_ L SPK_L SPK_R SPK_R Yes Yes Yes Yes Input the sound source p...

Page 52: ...4 23 4 Troubleshooting Main Board_Top E_TXCLK SPK R R L B12VS_PW Main Board_Bottom COMP2_SL_IN COMP2_SR_IN PC_DVI_SR_IN PC_DVI_SL_IN...

Page 53: ...4 24 4 Troubleshooting WAVEFORMS 7 Speaker out...

Page 54: ...hing is essential 4 Avoid overload Excessive signal from a sweep generator might overload the front end of the TV When inserting signal markers do not allow the marker generator to distort test result...

Page 55: ...te Option Control SVC Expert ADC WB Advanced T MSTMD C XXXX T MSTMD S XXXX EDID SUCCESS HDCP SUCCESS CALIB AV COMP PC HDMI Option XXXX XXXX T MSXDXX XXXX SDAL X XX X X RFS Mstar X5 XXXX 20XX XX XX FUN...

Page 56: ...ED_INA ED_ISRAEL COLOMBIA TAIWAN Select Area Model TA550 TA350 TA550 TA350_WOT Select Model TUNER SEC_TC SEC_ATSC SEC_TC ALPS_TC SI_TCS SI_T2 SEC_ISDB SEC_ATC SI_ATC SI_TW EU AU DVB TC DVB T SEC_TC S...

Page 57: ...I EDID WRITE HDMI1 EDID WRITE HDMI2 EDID WRITE HDMI3 EDID WRITE HDMI4 EDID VER EDID PORT EDID WRITE DVI Sub Option RS 232 Jack UART Debug Logic UART Select Setting of UART port Initial value is UART W...

Page 58: ...Singapol F CIS_Rusia C CIS_Ukraina B CIS_Kazakhstan C EU_Turkey A EU_Africa H EU_Moroco A EA_Vietnam F EA_Thai B EA_INA N EA_China N EA_India F EA_Srilanka R EA_Nepal J EA_Bangladesh F EA_Iran M EA_Is...

Page 59: ...ame Data Range Use Test Pattern Panel Auto Setting Panel Display Time 0Hr Logic Usb D L off Tuner Status T CON Usb Download MICOM UPGRADE off Set ON Sub micom upgrade after upgrade Main Micom over 5 m...

Page 60: ...ied Guard Interval_1 Not modified Freq Offset_1 Not modified SNR_1 Not modified IF AGC_1 Not modified TMCC Lock_1 Not modified TS Packet_1 Not modified Master Lock_1 Not modified A_Modulation_1 Not mo...

Page 61: ...AV_Delta 2 0 7 1st_COMP_Y_Low 64 0 1020 1st_COMP_Cb_Low 512 0 1020 1st_COMP_Cr_Low 512 0 1020 1st_COMP_Y_High 940 0 1020 1st_COMP_Cb_High 512 0 1020 1st_COMP_Cr_High 512 0 1020 1st_COMP_Delta 2 0 7 1s...

Page 62: ...255 WB Mode Sub Brightness 128 0 255 R_Offset 128 0 255 G_Offset 128 0 255 B_Offset 128 0 255 Sub Contrast 128 0 255 R_Gain 128 0 255 G_Gain 128 0 255 B_Gain 128 0 255 Movie R Offset 512 0 1023 Movie...

Page 63: ...lance Calibration 1 Calibration AV Calibration Comp Calibration PC Calibration HDMI Calibration 4 4 2 White Balance Adjustment 3 W B low light hight light Sub Bright R offset G offset B offset Sub Con...

Page 64: ...on and Manual setting for WB adjustment HDMI Calibration at 24 Chessboard Pattern Manual adjustment 92 pattern 720p COMP Calibration at 24 Chessboard Pattern Manual adjustment at 92 pattern 720p CVBS...

Page 65: ...ENTER button to select By USB The message Scanning for USB It may take up to 1 minute is displayed 4 The message Upgrade version XXXX to version XXXX The system will be reset after upgrade is display...

Page 66: ...tion 1 Connect DDC MANAGER to the TV Set with D SUB cable And Power on USB type MTI 2510 parallel type MTI 2059 2 Open the DDC tool Parallel type USB type Check the setting Manufacture WELTREND Device...

Page 67: ...g automatically Disconnect the JIG 4 7 2 Sub S W in Factory mode If you don t have DDC Manager Use this method 1 Into the Factory Mode 2 Select SVC Use r button 3 Select MICOM UPGRADE off use r button...

Page 68: ...x 327 7 555 7 x 31 6 x 345 6 578 6 x 33 2 x 359 1 Weight Kg Set with Stand 3 1 4 2 4 2 4 8 Set without Stand 2 8 3 6 3 6 4 2 4 8 2 LT22A550 LT23A550 LT24A550 LT27A550 W H d D H1 LT22A550 LT23A550 LT2...

Page 69: ...m 4 9 1 PCB layout Mian PCB CI IC1101 DDR H P OUT TUNER SCART COMP D SUB PC L R IC1102 DDR IC1301 FLASH IC1201 SUB MICOM CN1201 FUNCTION CNT CN302 SPEAKER CNT OPTICAL USB1 HDMI2 HDMI1 IC1111 X5 Scaler...

Page 70: ...4 41 4 Troubleshooting TOP BOTTOM...

Page 71: ...4 42 4 Troubleshooting SMPS PCB Model Inch CODE P N 20 23 BN44 00449B PD23A0_BPN Model Inch CODE P N 22 BN44 00448A PD22A0_BDY...

Page 72: ...4 43 4 Troubleshooting Model Inch CODE P N 24 27 BN44 00450A PD27A0_BDY...

Page 73: ...5 1 5 Wiring Diagram 5 Wiring Diagram 5 1 Wiring Diagram Main Board SMPS TCON Function IR SPEAKER SPEAKER CN1201 CN302 CN1603_HD CN201...

Page 74: ...l_VCC 16 EVEN 1 2 Panel_VCC 17 GND 3 Panel_VCC 18 EVEN 0 4 NC 19 EVEN 0 5 NC 20 ODD 3 6 NC 21 ODD 3 7 GND 22 ODDCLK 8 EVEN 3 23 ODDCLK 9 EVEN 3 24 GND 10 EVENCLK 25 ODD 2 11 EVENCLK 26 ODD 2 12 EVEN 2...

Page 75: ..._CVBS_OUT 19 GND 8 GND 20 SC_SL_IN 9 SC_FB 21 SC_SR_IN 10 GND 22 GND 11 SC_R 23 SC_SL_OUT 12 GND 24 SC_SR_OUT COMPONENT AV CN503 1 GND 6 GND 2 COMP_Y AV_CVBS 7 IDENT_COMP 3 COMP_PB 8 SL_IN 4 IDENT_AV...

Page 76: ...6p 4p use only AMLCD panel Supply power from IP board to Driver Board 5 4 Cables Use LEAD Main IP 14P LEAD IP Driver B D 4P LEAD IP Driver B D 6P Code 20 BN39 01455G 150mm 22 23 24 BN39 01455F 175mm 2...

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