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Doc No. 

 

Version 1.0 

TITLE 

Service Manual 

LCD TV For LT37HVS 

Page 3/39 

 

 

1.  Introduction 

1.1 Preface 

This service manual aims directly at the module of LCD TV. It offers the simple repair which 

emphasizes on technique explanation and production troubles to remove for the engineers and 

technicians who have electronic background.

 

 

1.2 Caution 

Be sure to read those manual before servicing. To assure safety from fire, electric shock, injury, 

harmful radiation and materials, various measures are provided in this Digimedia LCD TV. Be 

sure to read cautionary items described in the manual to maintain safety before servicing.

 

 

1.3 Warning 

1.  Remember to unplug the AC cord from the AC outlet before cleaning the product. And do 

not use liquid cleaners or aerosol cleaners to clean the display. 

2.  Do not place the product on an unstable place. It can cause the product to fall, resulting in 

serious personal injuries as well as damage to the product. 

3.  In case the product needs replacement parts, make sure that the service person uses 

replacement parts specified by the manufacturer, or those with the same characteristics and 

performance as the original parts. Use of unauthorized parts can result in fire, electric shock 

and/or other danger. 

4.  Do not overload AC outlets or extension cords. It can cause fire or electric shock. 

5.  The AC cords must be routed properly to prevent people from stepping on them or objects 

from resting on them. Check the cords at the plugs and product. 

6.  Do not hit the panel. Be careful to prevent from getting hurt by broken glass pieces in case 

the panel breaks. 

7.  Keep the product away from heat sources such as radiators, heaters, stoves and other 

heat-generating products. 

8.  Do not place the display near water. Like bathtub, washbasin, kitchen sink and laundry tub, 

swimming pool and in a wet basement. 

 

 

 

 

DigiMedia 

Summary of Contents for LT37HVS

Page 1: ...or LT37HVS Doc No Version 1 0 Total Pages 39 Approvals Job Function Signature Date CPO Project Manager R D Dept Manager EE Dept Manager ME Dept Manager Engineering Dept Manager Sales Dept Manager Qual...

Page 2: ...gram 2 3 Connector Pin Definition P4 P5 P6 3 Troubleshooting 3 1 No Power 3 2 No Sound 3 3 No Source Input 3 4 Keypad Failed 3 5 IR Failed 3 6 Indicator LED Failed P26 P26 P27 P28 P29 P30 P31 4 Firmwa...

Page 3: ...n unstable place It can cause the product to fall resulting in serious personal injuries as well as damage to the product 3 In case the product needs replacement parts make sure that the service perso...

Page 4: ...Doc No Version 1 0 TITLE Service Manual LCD TV For LT37HVS Page 4 39 2 System Block Diagram 2 1 System block diagram DigiMedia...

Page 5: ...Doc No Version 1 0 TITLE Service Manual LCD TV For LT37HVS Page 5 39 2 2 Connector Connection Diagram DigiMedia...

Page 6: ...No connection 6 GND GND 7 GND GND 8 GND GND 9 VGA5V I VCC 5V IN 10 GND GND 11 GND 12 VGASDA I O I2C data bus for Reading DDC dat 13 VGA_HS I Horizontal Sync 14 VGA_VS I Vertical Sync 15 VGASCL I I2C c...

Page 7: ...PLUG DETECT Function PC Audio In Connector type RCA Specification CNNT RCA white red F DIP RIGHT ANGLE 8 3 4PIN Pin Definition Pin No Pin Name I O Description 1 GND GND 2 AUD_R I Audio In_R 3 GND GND...

Page 8: ...Keypad to System 3 9 KEY_Y2 I Signal sent from Keypad to System 2 10 KEY_Y1 I Signal sent from Keypad to System 1 11 KEY_X3 O Signal sent from System to Keypad 3 12 KEY_X2 O Signal sent from System t...

Page 9: ...YCBCR AUDIO_L CH out 22 YCBCR_R O YCBCR AUDIO_R CH out 23 HDTV_L O HDTV_L AUDIO_L CH out 24 HDTV_R O HDTV_L AUDIO_R CH out 25 GND GND 26 SIF1_IN I SIF format _IN1 27 SIF2_IN I SIF format _IN2 28 GND...

Page 10: ...b woofer OUT 58 LINE_L O Audio Line L CH out 59 LINE_R O Audio Line R CH out 60 GND GND 61 SAL_SC2 I Audio CVBS2 SV2 L ch in 62 SAR_SC2 I Audio CVBS2 SV2 R ch in 63 CVBSAL_SC1 I Audio CVBS1 SV1 L ch i...

Page 11: ...rential data output Ch 3 11 TXECKP O Positive LVDS differential clock output 12 TXECKN O Negative LVDS differential clock output 13 GND GND 14 GND GND 15 TXE2P O Positive LVDS differential data output...

Page 12: ...DC Power 5V IN 5 V5 I DC Power 5V IN 6 GND GND 7 GND GND 8 GND GND 9 GND GND 10 V5 I DC Power 5V IN 11 GND GND 12 LCD_INVON O Inverter On Off 13 PWSTBY O Standby Mode Power 5V 14 BRI O Backlight Brig...

Page 13: ...o Out L Channel Connector type M3 I25002 Pecification CNNT M 3PIN pitch 2 5mm DIP straight white Pin Definition Pin No Pin Name I O Description 1 L_OUTN O Negative Audio Out_L 2 NC No connection 3 L_O...

Page 14: ...BCR AUDIO_L CH IN 22 YCBCR_R I YCBCR AUDIO_R CH IN 23 HDTV_L I HDTV_L AUDIO_L CH IN 24 HDTV_R I HDTV_L AUDIO_R CH IN 25 GND GND 26 SIF1_OUT O SIF format _OUT1 27 SIF2_OUT O SIF format _OUT2 28 GND GND...

Page 15: ...woofer IN 58 LINE_L I Audio Line L CH IN 59 LINE_R I Audio Line R CH IN 60 GND GND 61 SAL_SC2 O Audio CVBS2 SV2 L ch OUT 62 SAR_SC2 O Audio CVBS2 SV2 R ch OUT 63 CVBSAL_SC1 O Audio CVBS1 SV1 L ch OUT...

Page 16: ...2 I S Video1_Y2 In 5 GND GND 6 GND GND 7 S1AV_C1 I S Video1_C1 In 8 S1AV_Y1 I S Video1_Y1 In 9 GND GND 10 GND GND 11 GND GND 12 GND GND 13 GND GND Function CVBS 1 2 and CVBS 1 2 AUDIO 1 2 In Connector...

Page 17: ...ype RCA Specification CNNT RCA 2 white red Pin Definition Pin No Pin Name I O Description 1 LINE_L O Audio Line_L Out 2 LINE_R O Audio Line_R Out 3 GND GND Function Component 1 2 YPbPr1 YcbCr1 In Conn...

Page 18: ...ector type MD32 I20003 Specification CNNT M 32pin 16x2 pitch 2 0mm DIP straight Pin Definition Pin No Pin Name I O Description 1 V5_TUNER O POWER OUT_5V 2 12V O POWER OUT_12V 3 V5_TUNER O POWER OUT_5V...

Page 19: ...AV OUT P2S TO SYSTEM BOARD Connector type BOARD TO BOARD Specification 2 557100 1 CNNT Dip Right Angle M 80PIN 1 27mm 0 5A Board to Board Pin Definition Pin No Pin Name I O Description 1 CHKTNR1 O CHE...

Page 20: ...O Tuner2 CVBS OUT 30 IF_TU1CVBS O Tuner1 CVBS OUT 31 GND GND 32 V12_SYS2 I 12V IN 33 NC No connection 34 NC No connection 35 V12_SYS2 I 12V IN 36 PC2DTV_TX O PC TO DTV_TX OUT 37 PC2DTV_RX O PC TO DTV_...

Page 21: ...Software I2C Clk 67 SDA I O Software I2C data 68 HWSDA I O hardwae I2C data 69 HWSCL I hardwae I2C clk 70 GND GND 71 CVBS_SC2 O CVBS2 OUT 72 IF_YCVBS2 O S VIDEO2_Y OUT 73 IF_C2 O S VIDEO2_C OUT 74 AD...

Page 22: ...IO_L CH out 19 ARO_SC1 O Scart1 AUDIO_R CH out 20 GND GND 21 YCBCR_L O YCBCR AUDIO_L CH out 22 YCBCR_R O YCBCR AUDIO_R CH out 23 HDTV_L O HDTV_L AUDIO_L CH out 24 HDTV_R O HDTV_L AUDIO_R CH out 25 GND...

Page 23: ...EPOUT_L O Audio EARPHONE L CH OUT 56 EPOUT_R O Audio EARPHONE R CH OUT 57 AMP_WF O Audio Sub woofer OUT 58 LINE_L O Audio Line L CH out 59 LINE_R O Audio Line R CH out 60 GND GND 61 SAL_SC2 I Audio CV...

Page 24: ...tion 1 V18 I DC Power 18V IN 2 V18 I DC Power 18V IN 3 GND GND 4 GND GND 5 NC No connection Function Power Output Connector type M6 I25002 Specification CNNT M 6PIN pitch 2 5mm DIP straight Pin Defini...

Page 25: ...Keypad 3 12 KEY_X2 I Signal sent from System to Keypad 2 13 KEY_X1 I Signal sent from System to Keypad 1 14 GND GND 15 V5_IR I 5V POWER In Function Indicator Out Connector type M3 I20001 Specification...

Page 26: ...he power socket Power plug is securely inserted into the power socket 1 Check power to system cable 2 Check system to keypad cable 3 Check power to panel cable 4 Check keypad and remote control power...

Page 27: ...er wire to system board Check the input source and audio cable into the correct connector No No 1 Keep OSD is not in mute mode 2 Confirm the volume value is not 0 3 Power off and re plug power socket...

Page 28: ...r video source can t be found Check OSD select correct Confirm input source and the output of OSD select is correct Check image signal input at system board or interface board No No Replace system boa...

Page 29: ...e Manual LCD TV For LT37HVS Page 29 39 3 4 Keypad Failed Keypad no response 1 Check the cable of keypad to system board 2 Check keypad function 3 If item 1 and 2 have no problem please replace keypad...

Page 30: ...no response Check F W vision No Reinstall F W Check remote control has energy Change remote control battery Check keypad board connection into system board No No Replace Keypad or remote control or s...

Page 31: ...indicator board to keypad board No Check the cable of keypad board to system board Please connection the cable of keypad board to system board Check indicator board or keypad board connector insert P...

Page 32: ...gure2 Figure2 3 Insert the power cord and RS232 cable 4 Insert RS232 cable in Mouse socket or RS232 socket refer Figure3 and other side insert to service socket on TV refer Figure4 and Figure5 Figure4...

Page 33: ...ad Bin file option to choose the correct firmware 9 Click the bottom of Upgrade System will start upgrade firmware when it fished the operation list form has to show the Finished as blow arrow step 8...

Page 34: ...CD TV For LT37HVS Page 34 39 5 Disaggregate Graphic 5 1 TV Box DigiMedia 5 2 Stand Module 1 Loosen 4 screws as blue circles 2 Pull up the TV Box Cover as red arrow 3 Pull up the TV Box out as blue arr...

Page 35: ...Doc No Version 1 0 TITLE Service Manual LCD TV For LT37HVS Page 35 39 5 3 Back Cover 1 Please finished step 5 1 and 5 2 first 2 Loosen 19 screws as blue circles 3 Pull up the Back Cover DigiMedia...

Page 36: ...he Wall Mount Bracket 2 Loosen 10 screws as blue circles of Figure 2 3 4 then take off the PCBA Shielding 3 Loosen 7 screws as blue circles of Figure 5 and pull off connector as red circles of Figure...

Page 37: ...0 TITLE Service Manual LCD TV For LT37HVS Page 37 39 5 6 Keypad Board 1 Please loosen 6 screws as blue circles 2 Take off all of connector as red circles 5 7 Speaker 1 Please loosen 4 screws as blue c...

Page 38: ...e circles 2 Take apart the inverter connector as red circles 1 Loosen 14 screws as blue circles 2 Please pull off the LVDS wires carefully click the connector left side and right side 3 Take off the L...

Page 39: ...Doc No Version 1 0 TITLE Service Manual For LT37HVS Page 39 39 LCD TV 1 Loosen 8 screws as blue circles then can pick up LCD panel DigiMedia...

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