DigiMedia
Service Manual
LCD TV For 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
Quality Assurance Dept. Manager
Author
Doc No.
…
…
…
…
…
Version 1.0
Page 2/39
TITLE
Service Manual
LCD TV For LT37HVS
Table of Contents
1 Introduction……..…………..……………………………………… P3
1.1 Preface……………………………..……………………………………………… P3
1.2 Caution…………………………………..…...…………………………………… P3
1.3 Warning…………………………………………..………………………………. P3
2 System Block Diagram…………………………………………….. P4
2.1 System Block Diagram……………………………………………………………
2.2 Connector Connection Diagram………………………………………………….
2.3 Connector Pin Definition………………………………………………………...
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……………………………………………………………
P4
P5
P6
P26
P26
P27
P28
P29
P30
P31
4 Firmware upgrade applications…………………………………… P32
5 Disaggregate Graphic………………………………….……………
P34
5.1 TV Box……………………………………………………………………………
5.2 Stand Module………………………..…………………………………………….
5.3 Back Cover………………………………………………………………………...
5.4 System Board…………………………..………….……………………………..
5.5Indicator Board Module……………………………………....……...…………..
5.6 Keypad Board……………………………………………..……...…...…………..
5.7 Speaker…………………………………………………..…………………….…..
5.8 Power Module…………....………………………………………………………..
DigiMedia
P34
P34
P35
P36
P36
P37
P37
P38
Doc No.
Version 1.0
Page 3/39
TITLE
Service Manual
LCD TV For LT37HVS
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
TITLE
Service Manual
LCD TV For LT37HVS
2. System Block Diagram
2.1 System block diagram
Doc No.
Version 1.0
Page 4/39
DigiMedia
TITLE
2.2 Connector Connection Diagram
Service Manual
LCD TV For LT37HVS
Doc No.
Version 1.0
Page 5/39
DigiMedia
TITLE
2.3 Connector Pin Definition
Service Manual
LCD TV For LT37HVS
SYSTEM BOARD
Function: VGA Signal In port
Connector type :D-Sub
Doc No.
Version 1.0
Page 6/39
Specification: CNNT-HD D Sub-H-F-3Row-15pin-Dip-BLU
Pin Definition
Pin No. Pin Name I/O Description
1 VGAR I 75 ohm termination, 0.7Vp-p red sig
2 VGAG I 75 ohm termination, 0.7Vp-p green s
3 VGAB I 75 ohm termination, 0.7Vp-p blue si
4 GND - GND -
5 NC - 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 clock bus for Reading DDC da
Function: DVI/HDMI signal port
Connector type :HDMI
Specification:
HDMI/CRE-HM-19F4-01 CNNT HDMI Cnnt Right Angle M 2Row 19pin SMD
Pin Definition
Pin No. Pin Name I/O Description
1 RX2p I TMDS LVDS input signal
2 GND I GND
3 RX2m I TMDS LVDS input signal
4 RX1p I TMDS LVDS input signal
5 GND - GND
6 RX1m I TMDS LVDS input signal
7 RX0p I TMDS LVDS input signal
8 GND - GND
DigiMedia
Doc No.
Version 1.0
Page 7/39
TITLE
Service Manual
LCD TV For LT37HVS
9 RX0m I TMDS LVDS input signal
10 RXCp I TMDS LVDS input signal
11 GND - GND
12 RXCm I TMDS LVDS input signal
13 NC - No connection
14 NC No connection
15 DDC_CLK I/O I2C clock bus for Reading DDC data
16 DDC_DATA I/O I2C data bus for Reading DDC data
17 GND TMDS LVDS input signal
18 GDC5V I VCC5
19 HPD I HOT PLUG DETECT
Function: PC Audio In
Connector type: RCA
Specification: CNNT-RCA white / red -F DIP RIGHT ANGLE 8.3ψ-4PIN
Pin Definition
Pin No. Pin Name I/O Description
1 GND - GND
2 AUD_R I Audio In_R
3 GND - GND
4 AUD_L I Audio In_L
Function: RS-232 port
Connector type: Mini Din
Specification: CNNT-Mini Din-H-F-8pin-12ψ-Dip
Pin Definition
Pin No. Pin Name I/O Description
1 NC - No connection
2 FlsahDL# I Cable Plug In Detect
3 GND - GND
4 NC - No connection
5 NC - No connection
6 P_DGNS# - Download Function Control
7 PC_TXD O RS-232 Data Transmit
8 PC_RXD I RS-232 Data Receive
9 GND - GND
DigiMedia
Doc No.
Version 1.0
Page 8/39
TITLE
Service Manual
LCD TV For LT37HVS
10 GND - GND
11 GND - GND
Function: Keypad In
Connector type:M15-I20001
Specification: CNNT M 15PIN pitch 2.0mm DIP Straight WST(blue)
Pin Definition
Pin No. Pin Name I/O Description
1 NC - NC
2 LED_B1 O Signal for Indicator LED
3 LED_B1 O Signal for Indicator LED
4 LED_B1 O Signal for Indicator LED
5 GND - GND
6 IRD I IR Data In
7 GND - GND
8 KEY_Y3 I Signal sent from 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 to Keypad 2
13 KEY_X1 O Signal sent from System to Keypad 1
14 GND - GND
15 V5_IR O 5V POWER Out
Function: TUNER IN /AV IN
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 I CHECK AV Board In
2 V5_TUNER O POWER OUT_5V
3 V5_TUNER O POWER OUT_5V
4 GND - GND
5 GND - GND
6 NC - No connection
7 NC - No connection
DigiMedia
Doc No.
Version 1.0
Page 9/39
TITLE
Service Manual
LCD TV For LT37HVS
8 NC - No connection
9 NC - No connection
10 GND - GND
11 HD_PR I HD_PR In
12 HD_PB I HD_PB In
13 HD_Y I HD_Y In
14 SV_SEL1 O S_Video_SEL
15 GND - GND
16 ALO_SC2 O Scart2 AUDIO_L CH out
17 ARO_SC2 O Scart2 AUDIO_R CH out
18 ALO_SC1 O Scart1 AUDIO_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 - GND
26 SIF1_IN I SIF format _IN1
27 SIF2_IN I SIF format _IN2
28 GND - GND
29 IF_TU2CVBS I Tuner2 CVBS IN
30 IF_TU1CVBS I Tuner1 CVBS IN
31 GND - GND
32 V12_SYS2 O +12V OUT
33 NC - No connection
34 NC - No connection
35 V12_SYS2 O +12V OUT
36 PC2DTV_TX I PC TO DTV_TX IN
37 PC2DTV_RX I PC TO DTV_RX IN
38 S2DTV_TX I SYS TO DTV_TX IN
39 S2DTV_RX I SYS TO DTV_RX IN
40 RESETn I RESET
41 GND - GND
42 CVBS_SC1 I CVBS1 IN
43 IF_YCVBS I S-VIDEO1_Y In
DigiMedia
Doc No.
Version 1.0
Page 10/39
TITLE
Service Manual
LCD TV For LT37HVS
44 IF_C I S-VIDEO1_C In
45 GND - GND
46 OCVBS_SC2 O Scart2 cvbs out
47 IF_CR I YCBCR_CR IN
48 IF_CB I YCBCR_CB IN
49 IF_Y I YCBCR_Y IN
50 GND - GND
51 DTV_PR I DTV_ Pr In
52 DTV_PB I DTV_ Pb In
53 DTV_Y I DTV_ Y In
54 TPA_MODE I CHECK EARPHONE CONNECT In
55 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 CVBS2/SV2 L ch in
62 SAR_SC2 I Audio CVBS2/SV2 R ch in
63 CVBSAL_SC1 I Audio CVBS1/SV1 L ch in
64 CVBSAR_SC1 I Audio CVBS1/SV1 R ch in
65 GND - GND
66 SCL O Software I2C Clk
67 SDA I/O Software I2C data
68 HWSDA I/O hardwae I2C data
69 HWSCL O hardwae I2C clk
70 GND - GND
71 CVBS_SC2 I CVBS2 IN
72 IF_YCVBS2 I S-VIDEO2_Y In
73 IF_C2 I S-VIDEO2_C In
74 ADC2 I A/D conver
75 DTV_L I Audio DTV L ch in
76 DTV_R I Audio DTV R ch in
77 ADC1 I A/D conver
78 DTV_SPDIF I DTV audio format
79 ADC0 I A/D conver
DigiMedia
Doc No.
Version 1.0
Page 11/39
TITLE
Service Manual
LCD TV For LT37HVS
80 DTV_IR I DTV_IR pin
Function: LVDS output port
Connector type: TD01-30R1
Specification: CNNT-LVDS-F SMD STRAIGHT-V-30 PIN-1.25mm
Pin Definition
Pin No. Pin Name I/O Description
1 NC - No connection
2 GND - GND
3 NC - No connection
4 NC - No connection
5 NC - No connection
6 GND - GND
7 GND - GND
8 GND - GND
9 TXE3P O Positive LVDS differential data output Ch 3
10 TXE3N O Negative LVDS differential 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. Ch 2
16 TXE2N O Negative LVDS differential data output. Ch 2
17 TXE1P O Positive LVDS differential data output. Ch 1
18 TXE1N O Negative LVDS differential data output. Ch 1
19 TXE0P O Positive LVDS differential data output. Ch 0
20 TXE0N O Negative LVDS differential data output. Ch 0
21 GND - GND
22 GND - GND
23 GND - GND
24 GND - GND
25 GND - GND
26 VCC - +5.0V power supply
27 VCC - +5.0V power supply
28 VCC - +5.0V power supply
29 VCC - +5.0V power supply
DigiMedia
Doc No.
Version 1.0
Page 12/39
TITLE
Service Manual
LCD TV For LT37HVS
30 VCC - +5.0V power supply
Function: Power Input 1
Connector type:M15-I25002
Specification:
CNNT M 15PIN pitch 2.5mm DIP straight
Pin Definition
Pin No. Pin Name I/O Description
1 +V5_SYS I DC Power 5V IN
2 +V5 I DC Power 5V IN
3 +V5 I DC Power 5V IN
4 +V5 I 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 Brightness Control
15 GND - GND
Function: Power Input 2
Connector type:M11-I25002
Specification: CNNT M 11PIN pitch 2.5mm DIP straight
Pin Definition
Pin No. Pin Name I/O Description
1 +V12 I DC Power 12V IN
2 +V12 I DC Power 12V IN
3 +V12 I DC Power 12V IN
4 GND - GND
5 GND - GND
6 GND - GND
7 +12V I DC Power 12V IN
8 GND - GND
DigiMedia
Doc No.
Version 1.0
Page 13/39
TITLE
Service Manual
LCD TV For LT37HVS
9 +12V I DC Power 12V IN
10 GND - GND
11 GND - GND
Function: Audio Out (R Channel)
Connector type:M3-I25002
Specification: CNNT M 3PIN pitch 2.5mm DIP straight (red)
Pin Definition
Pin No. Pin Name I/O Description
1 R_OUTN O Negative Audio Out_R
2 NC - No connection
3 R_OUTP O Positive 0Audio Out_R
Function: Audio 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_OUTP O Positive 0Audio Out_L
AV BOARD
Function: TUNER OUT / AV OUT
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 CHECK AV Board In
2 V5_TUNER I POWER IN_5V
3 V5_TUNER I POWER IN_5V
4 GND - GND
5 GND - GND
6 NC - No connection
7 NC - No connection
DigiMedia
Doc No.
Version 1.0
Page 14/39
TITLE
Service Manual
LCD TV For LT37HVS
8 NC - No connection
9 NC - No connection
10 GND - GND
11 HD_PR O HD_PR OUT
12 HD_PB O HD_PB OUT
13 HD_Y O HD_Y OUT
14 SV_SEL1 I S_Video_SEL
15 GND - GND
16 ALO_SC2 I Scart2 AUDIO_L CH IN
17 ARO_SC2 I Scart2 AUDIO_R CH IN
18 ALO_SC1 I Scart1 AUDIO_L CH IN
19 ARO_SC1 I Scart1 AUDIO_R CH IN
20 GND - GND
21 YCBCR_L I YCBCR 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
29 IF_TU2CVBS 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_RX OUT
38 S2DTV_TX O SYS TO DTV_TX OUT
39 S2DTV_RX O SYS TO DTV_RX OUT
40 RESETn O RESET
41 GND - GND
42 CVBS_SC1 O CVBS1 OUT
43 IF_YCVBS O S-VIDEO1_Y OUT
DigiMedia
Doc No.
Version 1.0
Page 15/39
TITLE
Service Manual
LCD TV For LT37HVS
44 IF_C O S-VIDEO1_C OUT
45 GND - GND
46 OCVBS_SC2 I Scart2 cvbs IN
47 IF_CR O YCBCR_CR OUT
48 IF_CB O YCBCR_CB OUT
49 IF_Y O YCBCR_Y OUT
50 GND - GND
51 DTV_PR O DTV_ Pr OUT
52 DTV_PB O DTV_ Pb OUT
53 DTV_Y O DTV_ Y OUT
54 TPA_MODE O CHECK EARPHONE CONNECT OUT
55 EPOUT_L I Audio EARPHONE L CH IN
56 EPOUT_R I Audio EARPHONE R CH IN
57 AMP_WF I Audio Sub 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
64 CVBSAR_SC1 O Audio CVBS1/SV1 R ch OUT
65 GND - GND
66 SCL I 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 ADC2 O A/D conver
75 DTV_L O Audio DTV L ch OUT
76 DTV_R O Audio DTV R ch OUT
77 ADC1 O A/D conver
78 DTV_SPDIF O DTV audio format
79 ADC0 O A/D conver
DigiMedia
Doc No.
Version 1.0
Page 16/39
TITLE
Service Manual
LCD TV For LT37HVS
80 DTV_IR O DTV_IR pin
Function: S-Video1 1/2 In
Connector type: Mini Din
Specification: CNNT F 12PIN Mini Din DIP Right Angle 12ψ AMP( 2 S-Video)
Pin Definition
Pin No. Pin Name I/O Description
1 GND - GND
2 GND - GND
3 S1AV_C2 I S-Video1_C2 In
4 S1AV_Y2 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 type: RCA
Specification: CNNT-RCA*6 yellow&white&red / yellow&white&red
Pin Definition
Pin No. Pin Name I/O Description
1 CVBS1 I CVBS1 In
2 CVBS1_AR I CVBS1 Audio_R In
3 CVBS1_AL I CVBS1 Audio_L In
4 CVBS2 I CVBS2 In
5 CVBS2_AR I CVBS2 Audio_R In
6 CVBS2_AL I CVBS2 Audio_L In
7 GND - GND
8 GND - GND
9 GND - GND
DigiMedia
TITLE
Function: Earphone Out
Connector type: PHONE JACK
Service Manual
LCD TV For LT37HVS
Doc No.
Version 1.0
Page 17/39
Specification: CNNT-EAR Phone Jack-H-F-5pin-3.6ψ-Dip
Pin Definition
Pin No. Pin Name I/O Description
1 EAR_ROUT O EAR Audio_R OUT
2 GND - GND
3 TPA_MODE O TPA_MODE
4 EAR_LOUT O EAR Audio_L OUT
5 GND - GND
Function: Audio Output Port (Line Out)
Connector type: 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
Connector type: RCA
Specification: CNNT-RCA*6 green&blue&red / green&blue&red
Pin Definition
Pin No. Pin Name I/O Description
1 COM1_Y I Component1_Y In
2 COM1_Pb I Component1_Pb In
3 COM1_Pr I Component1_Pr In
4 COM2_Y I Component2_Y In
5 COM2_Cb I Component2_Cb In
6 COM2_Cr I Component2_Cr In
7 GND - GND
8 GND - GND
9 GND - GND
Function: Component 1/2 Audio 1/2 In
DigiMedia
Doc No.
Version 1.0
Page 18/39
TITLE
Connector type: RCA
LCD TV For LT37HVS
Service Manual
Specification: CNNT-RCA*4 white&red / white&red
Pin Definition
Pin No. Pin Name I/O Description
1 COM1_AL I Component1 Audio_L In
2 COM1_AR I Component1 Audio_R In
3 COM2_AL I Component2 Audio_L In
4 COM2_AR I Component2 Audio_R In
5 GND - GND
6 GND - GND
Function: Digital Tuner Out
Connector 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
4 +12V O POWER OUT_12V
5 GND - GND
6 GND - GND
7 S2DTV_TX I SYS TO DTV_TX IN
8 RESETn O RESET
9 S2DTV_RX I SYS TO DTV_RX IN
10 MAIN_DE I MAIN_DE pin
11 GND - GND
12 GND - GND
13 PC2DTV_TX I PC TO DTV_TX IN
14 SCL I Sofeware I2C Clk
15 PC2DTV_RX I PC TO DTV_RX IN
16 SDA I/O Sofeware I2C data
17 GND - GND
18 GND - GND
19 DTV_Y I DTV_Y In
20 DTV_SPDIF I DTV audio format
DigiMedia
Doc No.
Version 1.0
Page 19/39
TITLE
Service Manual
LCD TV For LT37HVS
21 GND - GND
22 DTV_SPDIF I DTV audio format
23 DTV_Pb I DTV_Pb In
24 GND - GND
25 GND - GND
26 DTV_L I Audio DTV L ch IN
27 DTV_Pr I DTV_Pr In
28 DTV_R I Audio DTV R ch IN
29 DTV_DL I DTV_DL pin
30 DTV_IR I DTV_IR pin
31 DTV_NM I DTV_NM pin
32 GND - GND
P2S BOARD
Function: TUNER OUT / 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 CHECK AV Board In
2 V5_TUNER I POWER IN_5V
3 V5_TUNER I POWER IN_5V
4 GND - GND
5 GND - GND
6 NC - No connection
7 NC - No connection
8 NC - No connection
9 NC - No connection
10 GND - GND
11 HD_PR O HD_PR OUT
12 HD_PB O HD_PB OUT
13 HD_Y O HD_Y OUT
14 SV_SEL1 I S_Video_SEL
15 GND - GND
16 ALO_SC2 I Scart2 AUDIO_L CH IN
17 ARO_SC2 I Scart2 AUDIO_R CH IN
DigiMedia
Doc No.
Version 1.0
Page 20/39
TITLE
Service Manual
LCD TV For LT37HVS
18 ALO_SC1 I Scart1 AUDIO_L CH IN
19 ARO_SC1 I Scart1 AUDIO_R CH IN
20 GND - GND
21 YCBCR_L I YCBCR 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
29 IF_TU2CVBS 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_RX OUT
38 S2DTV_TX O SYS TO DTV_TX OUT
39 S2DTV_RX O SYS TO DTV_RX OUT
40 RESETn O RESET
41 GND - GND
42 CVBS_SC1 O CVBS1 OUT
43 IF_YCVBS O S-VIDEO1_Y OUT
44 IF_C O S-VIDEO1_C OUT
45 GND - GND
46 OCVBS_SC2 I Scart2 cvbs IN
47 IF_CR O YCBCR_CR OUT
48 IF_CB O YCBCR_CB OUT
49 IF_Y O YCBCR_Y OUT
50 GND - GND
51 DTV_PR O DTV_ Pr OUT
52 DTV_PB O DTV_ Pb OUT
53 DTV_Y O DTV_ Y OUT
DigiMedia
Doc No.
Version 1.0
Page 21/39
TITLE
Service Manual
LCD TV For LT37HVS
54 TPA_MODE O CHECK EARPHONE CONNECT OUT
55 EPOUT_L I Audio EARPHONE L CH IN
56 EPOUT_R I Audio EARPHONE R CH IN
57 AMP_WF I Audio Sub 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
64 CVBSAR_SC1 O Audio CVBS1/SV1 R ch OUT
65 GND - GND
66 SCL I 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 ADC2 O A/D conver
75 DTV_L O Audio DTV L ch OUT
76 DTV_R O Audio DTV R ch OUT
77 ADC1 O A/D conver
78 DTV_SPDIF O DTV audio format
79 ADC0 O A/D conver
80 DTV_IR O DTV_IR pin
Function: TUNER IN /AV IN TUNER TO P2S 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 I CHECK AV Board In
2 V5_TUNER O POWER OUT_5V
3 V5_TUNER O POWER OUT_5V
DigiMedia
Doc No.
Version 1.0
Page 22/39
TITLE
Service Manual
LCD TV For LT37HVS
4 GND - GND
5 GND - GND
6 NC - No connection
7 NC - No connection
8 NC - No connection
9 NC - No connection
10 GND - GND
11 HD_PR I HD_PR In
12 HD_PB I HD_PB In
13 HD_Y I HD_Y In
14 SV_SEL1 O S_Video_SEL
15 GND - GND
16 ALO_SC2 O Scart2 AUDIO_L CH out
17 ARO_SC2 O Scart2 AUDIO_R CH out
18 ALO_SC1 O Scart1 AUDIO_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 - GND
26 SIF1_IN I SIF format _IN1
27 SIF2_IN I SIF format _IN2
28 GND - GND
29 IF_TU2CVBS I Tuner2 CVBS IN
30 IF_TU1CVBS I Tuner1 CVBS IN
31 GND - GND
32 V12_SYS2 O +12V OUT
33 NC - No connection
34 NC - No connection
35 V12_SYS2 O +12V OUT
36 PC2DTV_TX I PC TO DTV_TX IN
37 PC2DTV_RX I PC TO DTV_RX IN
38 S2DTV_TX I SYS TO DTV_TX IN
39 S2DTV_RX I SYS TO DTV_RX IN
DigiMedia
Doc No.
Version 1.0
Page 23/39
TITLE
Service Manual
LCD TV For LT37HVS
40 RESETn I RESET
41 GND - GND
42 CVBS_SC1 I CVBS1 IN
43 IF_YCVBS I S-VIDEO1_Y In
44 IF_C I S-VIDEO1_C In
45 GND - GND
46 OCVBS_SC2 O Scart2 cvbs out
47 IF_CR I YCBCR_CR IN
48 IF_CB I YCBCR_CB IN
49 IF_Y I YCBCR_Y IN
50 GND - GND
51 DTV_PR I DTV_ Pr In
52 DTV_PB I DTV_ Pb In
53 DTV_Y I DTV_ Y In
54 TPA_MODE I CHECK EARPHONE CONNECT In
55 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 CVBS2/SV2 L ch in
62 SAR_SC2 I Audio CVBS2/SV2 R ch in
63 CVBSAL_SC1 I Audio CVBS1/SV1 L ch in
64 CVBSAR_SC1 I Audio CVBS1/SV1 R ch in
65 GND - GND
66 SCL O Software I2C Clk
67 SDA I/O Software I2C data
68 HWSDA I/O hardwae I2C data
69 HWSCL O hardwae I2C clk
70 GND - GND
71 CVBS_SC2 I CVBS2 IN
72 IF_YCVBS2 I S-VIDEO2_Y In
73 IF_C2 I S-VIDEO2_C In
74 ADC2 I A/D conver
75 DTV_L I Audio DTV L ch in
DigiMedia
Doc No.
Version 1.0
Page 24/39
TITLE
Service Manual
LCD TV For LT37HVS
76 DTV_R I Audio DTV R ch in
77 ADC1 I A/D conver
78 DTV_SPDIF I DTV audio format
79 ADC0 I A/D conver
80 DTV_IR I DTV_IR pin
Function: Power Input
Connector type:M5-I25002
Specification:
CNNT M 5PIN pitch 2.5mm DIP straight
Pin Definition
Pin No. Pin Name I/O Description
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 Definition
Pin No. Pin Name I/O Description
1 +V12 O DC Power 12V OUT
2 +V12 O DC Power 12V OUT
3 GND - GND
4 GND - GND
5 +V18 O DC Power 18V OUT
6 +V18 O DC Power 18V OUT
KEYPAD BOARD
Function: Keypad In
Connector type: M15-I20001
Specification: CNNT M 15PIN pitch 2.0mm DIP Straight WST
Pin Definition
Pin No. Pin Name I/O Description
1 NC - NC
DigiMedia
Doc No.
Version 1.0
Page 25/39
TITLE
Service Manual
LCD TV For LT37HVS
2 LED_B1 I Signal for Indicator LED
3 LED_B1 I Signal for Indicator LED
4 LED_B1 I Signal for Indicator LED
5 GND - GND
6 IRD O IR Data Out
7 GND - GND
8 KEY_Y3 O Signal sent from Keypad to System 3
9 KEY_Y2 O Signal sent from Keypad to System 2
10 KEY_Y1 O Signal sent from Keypad to System 1
11 KEY_X3 I Signal sent from System to 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: CNNT M 3PIN pitch 2.0mm DIP Straight WST
Pin Definition
Pin No. Pin Name I/O Description
1 V5_Indicator O 5V POWER Out
2 LED_B1 I Signal for Indicator LED
3 GND - GND
INDICATOR BOARD
Function: Signal In
Connector type: M3-I20001
Specification: CNNT M 3PIN pitch 2.0mm DIP straight
Pin Definition
Pin No. Pin Name I/O Description
1 V5_KEY1 I 5V POWER IN
2 LED I Signal for Indicator LED
3 GND - GND
DigiMedia
TITLE
p
N
N
p
LCD TV For LT37HVS
3. Troubleshooting
3.1 No Power
Service Manual
No Power
Doc No.
Version 1.0
Page 26/39
Check power plug is
securely inserted into the
ower socket?
Yes
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 key connector
insert?
Power plug is
o
securely inserted
into the power
socket.
o
Please replace the
cable what cause the
ower on failed.
Yes
If power on still failed, please replace power module.
DigiMedia
TITLE
N
N
3.2 No Sound
Service Manual
LCD TV For LT37HVS
No Sound
Doc No.
Version 1.0
Page 27/39
Check the speaker wire
connector to system
board?
Yes
Check the input source
and audio cable into the
correct connector?
Please connection
o
the speaker wire to
system board.
Confirm input
o
source and audio
cable select to the
correct channel.
Yes
1. Keep OSD is not in mute mode.
2. Confirm the volume value is not 0.
3. Power off, and re-plug power socket again.
4. If items 1,2 and 3 have no problem, replace
interface board or system board.
DigiMedia
TITLE
N
N
LCD TV For LT37HVS
3.3 No Source Input
RGB or video source can’t be found
Service Manual
Doc No.
Version 1.0
Page 28/39
Check OSD select
correct?
Yes
Check image signal input
at system board or
interface board?
Confirm input
o
source and the
output of OSD select
is correct.
Check input source
o
cable connection
into the connector.
Yes
Replace system board or interface board.
DigiMedia
TITLE
3.4 Keypad Failed
Service Manual
LCD TV For LT37HVS
Doc No.
Version 1.0
Page 29/39
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 board or system board.
DigiMedia
TITLE
N
N
N
3.5 IR Failed
Service Manual
LCD TV For LT37HVS
IR no response
Doc No.
Version 1.0
Page 30/39
Check F/W vision?
Yes
Check remote control
has energy?
Yes
o
o
Reinstall F/W .
Change remote
control battery.
Check keypad board
connection into system
board?
o
Please connection
the keypad board
into system board.
Yes
Replace Keypad or remote control or
system board.
DigiMedia
TITLE
N
N
N
Service Manual
LCD TV For LT37HVS
3.6 Indicator LED Failed
Indicator LED is not bright
Doc No.
Version 1.0
Page 31/39
Check the cable of
indicator board to keypad
board?
Yes
Check the cable of
keypad board to system
board?
Yes
Check indicator board or
keypad board connector
o
Please connection the
cable of indicator board
to keypad board.
o
Please connection the
cable of keypad board
to system board.
Please connection the
o
indicator board into
keypad board or keypad
board into system board.
Yes
Replace indicator board.
If indicator LED still
unlighted, please replace
keypad board or system
board.
DigiMedia
TITLE
Service Manual
LCD TV For LT37HVS
4. Firmware upgrade applications
Doc No.
Version 1.0
Page 32/39
1. Update Firmware tools：
1.PC(Notebook)
2. transmission line as Figure1
3.Sofeware(
MtkTool.exe , COMPR.DLL , MTKDLL.DLL)
2. Cable switch: on D side (refer Figure2)
Figure1
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)
Figure3
Figure4
Figure5
5. There are some files should be in directory. (MtkTool.exe , COMPR.DLL , MTKDLL.DLL)
Figure6
6. Execute MtkTool.exe.(step 6 and step 7 please refer Figure 6)
7. Make sure IC model is MT8205, serial connection is correct(default is COM1) and baud rate is
115200.
DigiMedia
TITLE
8. Click the Browse of “Load 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
Service Manual
LCD TV For LT37HVS
Doc No.
Version 1.0
Page 33/39
form has to show the “Finished” as blow arrow (step 8 and step 10 please refer the Figure7)
10. pull out the RS232 cable and AC cord.
Figure7
DigiMedia
TITLE
Service Manual
LCD TV For LT37HVS
5. Disaggregate Graphic
5.1 TV Box
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 arrow.
Doc No.
Version 1.0
Page 34/39
1. Loosen handle screws as blue circles.
DigiMedia
TITLE
5.3 Back Cover
Service Manual
LCD TV For LT37HVS
1. Please finished step 5.1 and 5.2 first.
2. Loosen 19 screws as blue circles.
3. Pull up the Back Cover.
Doc No.
Version 1.0
Page 35/39
DigiMedia
Doc No.
Version 1.0
Page 36/39
TITLE
Service Manual
LCD TV For LT37HVS
5.4 System Board
Figure 1
Figure 3
Figure 2
Figure 5
1. Loosen 5 screws as blue circles of Figure 1 and take off the 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 5.
5.5 Indicator Board Module
Figure 1
1. Please loosen 2 screws as blue circles to take off the Chin Metal.
2. Loosen 4 screws as blue circles to take apart the Indicator board.
Figure 4
Figure 2
DigiMedia
TITLE
5.6 Keypad Board
5.7 Speaker
Service Manual
LCD TV For LT37HVS
1. Please loosen 6 screws as blue circles.
2. Take off all of connector as red circles.
1. Please loosen 4 screws as blue circles.
Doc No.
Version 1.0
Page 37/39
DigiMedia
TITLE
Service Manual
LCD TV For LT37HVS
5.8 Power Module and LCD Panel Module
1. Loosen 6 screws as blue 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 LCD Support Metal.
Doc No.
Version 1.0
Page 38/
39
1. Pull out all of wires as red circles
2. Loosen 8 screws as blue circles.
3. pick off the LCD Support Metal.
DigiMedia
TITLE
Service Manual
LCD TV
For LT37HVS
Doc No.
Version 1.0
Page 39/39
1. Loosen 8 screws as blue circles, then can pick up LCD panel.
DigiMedia
Loading...