Daewoo DLT-37C7, DLT-37C3, DLT-32C7, DLT-32C6, DLT-32C3 Service Manual

S/M NO. : DSL500TEF0

Service Manual

LCD TV

CHASSIS : SL-500T

Model : DLT-26C2

DLT-26C3

DLT-32C1

DLT-32C2

DLT-32C3

DLT-32C6

DLT-32C7

DLT-37C3

DLT-37C7

Sep. 2007

Contents

1.Safety Precaution ………………………………………………………………………………… 3 2.Product Specification …………………………………………………………………………… 4 2-1.Product Specification………………………………………………………………………… 4 2-2.Available Input Signal ……………………………………………………………………… 5 3.Block Diagram …………………………………………………………………………………… 6 3-1.Block Diagram(Signal) ……………………………………………………………………… 6 3-2.Block Diagram(Power) ……………………………………………………………………… 7 4.Description of Each Block ……………………………………………………………………… 8 4-1.Block Diagram of Main IC and TP ………………………………………………………… 8

4-2.Overview ……………………………………………………………………………………… 9 4-2-1.Composite video, Y/C(S-Video) and SCART(CVBS, RGB) composite video … 9 4-2-2.DTV/DVD signal ……………………………………………………………………… 11 4-2-3.PC(Personal Computer)signal ……………………………………………………… 13 4-2-4.HDMI signal …………………………………………………………………………… 15 4-2-5.R/G/B Processing(SCART1, TELETEXT R/G/B) ………………………………… 15 4-2-6.Audio signal processing, KEY, and LED …………………………………………… 17

4-3.POWER PCB ………………………………………………………………………………… 21 5.SERVICE MODE ………………………………………………………………………………… 24 5-1.Entering SERVICE MODE ………………………………………………………………… 24 6.Main PCBs Trouble Diagnosis ………………………………………………………………… 26 6-1.Main PCBs Trouble Diagnosis ……………………………………………………………… 26 6-1-1.Common checking process when “No signal of Noraster” ……………………… 26 6-1-2.When No Sound ……………………………………………………………………… 33 6-1-3.When Control Key does not operate………………………………………………… 35 6-1-4.When Remote Controller does not operate ………………………………………… 36 6-2.POWER PCB ………………………………………………………………………………… 38 7.Trouble Diagnosis ………………………………………………………………………………… 39 7-1.Facts you must know when Diagnosis or Repairing……………………………………… 39 7-2.Typical Symptoms of PCB problem or bad connection ………………………………… 40 8.Structure of LCD Set …………………………………………………………………………… 41 9.Exploded View …………………………………………………………………………………… 43 10.Service Part List ………………………………………………………………………………… 52 11.Circuit Diagram ………………………………………………………………………………… 98

-2-

1.Safety Precautions

(1)When moving or laying down a LCD Set, please deal with care. Avoid any impact towards the LCD Set.

(2)Do not leave a broken LCD Set on for a long time. To prevent any further damages, after check the broken Set’s condition, make sure to turn the power (AC) off.

(3)When opening the BACK COVER, you must turn off power (AC) to prevent any electric shock.

(4)When loosening screws, check the connecting position and type of the screw.

Sort out the screws and store them separately

Because screws holding PCBs are working as electric circuit grounding, make sure to check if any screw is missing when assembling.

(5) A LCD Set contains different kinds of connector cables.

When connecting or disconnecting connector cables, check the direction and position of the cable beforehand.

(6)When disconnecting connectors unplug the connectors slowly with care.

(7)Connectors are designed so that if the number of pins or the direction does not match, connectors will not fit.

When having problem in plugging the connectors, make sure to check their kind, position, and direction.

-3-

2. Product Specification

2-1.PRODUCT SPECIFCATION

Features		DLT-26C2SMDB	DLT-32C6LMBD	DLT-32C6SMBD	DLT-37C3LMBD
	Screen Size	26”	32”	32”	37”
	Aspect Ratio	16 : 9	16 : 9	16 : 9	16 : 9
LCD Panel
	Resolution	1366x768(WXGA)	1366x768(WXGA)	1366x768(WXGA)	1366x768(WXGA)
	Pixel Pitch	0.421(H) x	170.25um x	0.51075(H) x	0.200mm x
		0.140(W)*3mm	510.75um x RGB	0.17025(W)*3	0.600mm x RGB
	Contrast	1200 : 1	800 : 1	800 : 1	800 : 1
	Ratio
	Receiving	PAL, SECAM	PAL, SECAM	PAL, SECAM	PAL, SECAM
	System
TV System	Stereo	FM MONO /	FM MONO /	FM MONO /	FM MONO /
	System	2-Carrier, NICAM	2-Carrier, NICAM	2-Carrier, NICAM	2-Carrier, NICAM
	Channel	ANALOG : 0~99CH	ANALOG : 0~99CH	ANALOG : 0~99CH	ANALOG : 0~99CH
	Memory
	RF	75 Ohm Coaxial	75 Ohm Coaxial	75 Ohm Coaxial	75 Ohm Coaxial
	S-Video	1	1	1	1
Input	SCART	2	2	2	2
Connector	Component	RCA X 1	RCA X 1	RCA X 1	RCA X 1
	PC RGB	D-Sub X 1	D-Sub X 1	D-Sub X 1	D-Sub X 1
	PC Audio	3.5mm Mini-Jack	3.5mm Mini-Jack	3.5mm Mini-Jack	3.5mm Mini-Jack
	HDMI	1	1	1	1
Output	Headphone	3.5mm Mini-Jack	3.5mm Mini-Jack	3.5mm Mini-Jack	3.5mm Mini-Jack
Connector
Sound		10W	10W	10W	10W
Output
Power	Max	100W	115W	135W	150W
Consumption	Power	180VAC ~ 264VAC,	180VAC ~ 264VAC,	180VAC ~ 264VAC,	180VAC ~ 264VAC,
	Source	50~60Hz	50~60Hz	50~60Hz	50~60Hz
Dimension	Set	812 x 502.7 x 240	806 x 628.5 x 250	806 x 628.5 x 250	940 x 720 x 328.7
(W x H x D)	Dimension

-4-

Product Specification

2-2.Available Input Signal

2-2-1.HDMI/PC/COMPONENT

Resolution	V-freg	HDMI	PC(D-Sub)	Component	Standard
	60Hz	O	O	X
640 x 480
	72Hz	O	O	X
	75Hz	O	O	X	VESA Standard
	60Hz	O	O	X	VESA Standard
800 x 600
	72Hz	O	O	X	VESA Standard
	75Hz	O	O	X
	60Hz	O	O	X	VESA Standard
1024 x 768
	70Hz	O	O	X	VESA Standard
	75Hz	O	O	X	VESA Standard
1360 x 768	60Hz	O	O	X
	75Hz	O	O	X
720 x 480	60Hz	O	X	O
720 x 576	50Hz	O	X	O
1280 x 720	50Hz	O	O	O
	60Hz	O	O	O
1920 x 1080i	50Hz	O	X	O
	60Hz	O	X	O
720 x 480i	60Hz	X	X	O
720 x 576i	50Hz	X	X	O

2-2-2.VIDEO

-PAL, PAL-M, PAL-N

-NTSC, NTSC4.43

-SECAM

-5-

3. Block Diagram

3-1.Block Diagram(Signal)

-6-

Block Diagram

3-2.Block Diagram(Power)

-7-

4. Description of Each Block

4-1.Block Diagram of Main IC and TP

-8-

Description of Each Block

4-2.Overview

Digital PCB is Multi Media circuit board that can process carious input signals such as Video, component, PC, HDMI, and analog TV signal.

4-2-1.Composite video, Y/C(S-Video) and SCART(CVBS, RGB) composite video -Flow Chart of RF, Video, S-Video Signal

Y-pb-pr

AV3-Y/C

Scart1-rgb-fb

Tuner Cvbs

Scart1-Cvbs U8

MST96889LD

Scart1-Cvbs
AV3-Cvbs	LVDS

R-G-B

HY HDMI

TMDS-IN

-9-

Description of Each Block

Y signal(input to U8)

Location:R199

Color signal(input to U8)

Location:R173

-10-

Description of Each Block

CVBS signal(input to U8)

Location:R203

4-2-2.DTV/DVD signal

Y signal(input to U8)

Location:R171

-11-

Description of Each Block

PB signal(input to U8)

Location:R193

Pr signal(input to U8)

Location:R167

-12-

Description of Each Block

4-2-3.PC(Personal Conputer) signal

R signal(input to U8)

Location:R150

G signal(input to U8)

Location:R149

B signal(input to U8)

Location:R147

-13-

Description of Each Block

Horizontal sync(Output of U8) Location:R89

Vertical sync(Output of U13)

Location:R91

-14-

Description of Each Block

4-2-4.HDMI signal

Location:R62, R63, R64, R65, R66, R67, R68, R69

4-2-5.R/G/B PROCESSING(SCART 1, TELETEXT R/G/B)

R signal(input to U8)

Location:R159

-15-

Description of Each Block

G signal(input to U8)

Location:R156

B signal(input to U8)

Location:R184

-16-

Description of Each Block

4-2-6.Audio signal processing, KEY, and LED -Flow Chart of Audio Signal

RF(SIF)

SC1

SC2

AV3

COMP

PC

	12S	U1		SC1-OUT
		W M 8521			Speaker L &
	Sound L				Headphone L
U8				U12
				TDA8931T
M ST96889LD		U13
					Speaker R&
	Sound R	TDA1308
				U14	Headphone R
				TDA8931T

HDMI

Pre AMP input

Location:CE38, CE39

-17-

Description of Each Block

U12, U14 input

Location:CE33, CE43

U12, U14 output

Location:C199, C215

-18-

Description of Each Block

SIF input

Location:R124

I2S input

Location:R19(CLK)

-19-

Description of Each Block

Location:R20

Remote control signal

Location:L73

-20-

Description of Each Block

4-3.Power PCB

4-3-1.Power Spec -Rating:180V ~ 264V -Regulating Method:

-Input Frequency : 50/60Hz

-Inrush Current : Below 80A at AC 230V -Output Voltage and Current are shown below

26” & 32”

Board

Output

Minimum

Maxmum

Output Current

Condition

Output

Output

Voltage

MIN

NOR

MAX

Voltage

Voltage

+29Vdc

+27.0Vdc

+32.0Vdc

0.1A

0.5A

0.7A

+24Vdc

+22.3Vdc

+25.4Vdc

0.3A

5.2A

6.0A

PWR-CTL

DEP

+12Vdc

+11.0Vdc

+12.0Vdc

0.3A

1.2A

2.0A

ON

+ 5Vdc

+4.75Vdc

+5.25Vdc

0.1A

1.5A

2.0A

ST+5Vdc

+4.75Vdc

+5.25Vdc

0.1A

0.2A

0.3A

PWR-CTL

OFF

37”

Board

Output

Minimum

Maxmum

Output Current

Condition

Output

Output

Voltage

MIN

NOR

MAX

Voltage

Voltage

+29Vdc

+27.0Vdc

+32.0Vdc

0.1A

0.5A

0.7A

+24Vdc

+22.3Vdc

+25.4Vdc

0.3A

5.6A

6.5A

PWR-CTL

DEP

+12Vdc

+11.0Vdc

+12.0Vdc

0.3A

1.2A

2.0A

ON

+ 5Vdc

+4.75Vdc

+5.25Vdc

0.1A

1.5A

2.0A

ST+5Vdc

+4.75Vdc

+5.25Vdc

0.1A

0.2A

0.3A

PWR-CTL

OFF

-Ripple and Noise

Output Valtage

AC ripple, switching ripple

Output

and noise

Condition

Minimum

Maxmum

Name

Continuous

Output Voltage

Output Voltage

+29V

+27.0Vdc

+32.0Vdc

+24V

+22.3Vdc

+25.4Vdc

500mVp-p

PWR-CTR

+12V

+11.0Vdc

+12.0Vdc

ON

+ 5V

+4.75Vdc

+5.25Vdc

MAX LOAD

ST+5V

+4.75Vdc

+5.25Vdc

500mVp-p

PWR-CTL

Other Lines

Don’t Care

OFF

-21-

Description of Each Block

4-3-2.Connectors

A. CN7, CN8 pin Spec(YEON-HO 20010WS-14 14P)
		CN7(AUO PANNEL)								CN8(SAMSUNG PANNEL)
				PIN No.		Output						PIN No.	Output
												1	+24V
				1		+24V
												2	+24V
				2		+24V
												3	+24V
				3		+24V
												4	+24V
				4		+24V
												5	+24V
				5		+24V
												6	GND
				6		GND
												7	GND
				7		GND
												8	GND
				8		GND
												9	GND
				9		GND
													GND
				10		GND						10
												11	N/C
				11		DIMIMING
												12	INV ON/OFF
				12		INV ON/OFF
												13	DIMIMING
				13		N/C
												14	N/C
				14		GND
B. CN5, CN6 pin Spec(YEON-HO 20010WS-12 12P)
CN5,CN6(LG PANNEL)
				PIN No.		Output
		1				+24V
		2				+24V
		3				+24V
		4				+24V
		5				+24V
		6				GND
		7				GND
		8				GND
		9				GND
		10				GND
		11				DIMIMING
		12				INV ON/OFF

-22-

Description of Each Block

C.CN2 Pin Spec(YEON-HO YW025-04 4P)

PIN No.	Output
1	+29V
2	+29V
3	GND
4	GND

D.CN4 Pin Spec(YEON-HO SMW025-09 9P)

PIN No.	Output
1	+12V
2	+12V
3	GND
4	GND
5	+5VS
6	PWR ON/OFF
7	GND
8	GND
9	+5VS

E.CN3 Pin Spec(CA3237W-300-08P)

PIN No.	Output
1	DIMIMING
2	INV ON/OFF
3	N/C
4	GND
5	GND
6	+5VS
7	+5VS
8	+12V

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5. SERVICE MODE

5-1.Entering SERVICE MODE

Using the Service Remote controller, you can enter service mode directly.

	5-1-1.Adjustment REMOCON and EEPROM Initial DATA
	A.The adjustment Specification use the SERVICE REMOCON R-34SVC
	(S/N:48B3034SVC)
	B.Adjustment DATA					2007. 05. 11
Key	Menu			Sub Menu	Default Value	Description
S1	Heat Run Mode				Full White	to enter into Heat Run Mode
S2	Gumi Ch Map Write					to set Gumi factory channels directly
S3	Volume Test				0-50-100-L-R	to set sound(display in sequence)
S4	HDMI EDID WRITE					to write HDMI EDID data directly from main chip
S5	Test Pattem				Black-W-R-G-B	to display Test Pattem in sequence
					Bri_Min-Cen-Max	to test picture(displays in sequence)
S6
	Picture Test				Con_Min-Cen-Max	to test picture(displays in sequence)
					Col_Min-Cen-Max	to test picture(displays in sequence)
S7	DEMPOL CH Map Write					to test picture(displays in sequence)
				input Source Display		to display present input source mode
				Offset R	32
				Offset G	32
				Offset B	32
S8	Write Balance					to display offset and gain value at mode above
				Gain R	32
				Gain G	32
				Gain B	32
				Read Value	32	to display the matched real value of the offset
						and gain
				Speaker_SIF	32
				Speaker_AV3 DVB	37
				Speaker_AV2	43
	Sound Prescale			Speaker_HDMI	47	to display sound prescale value at each mode
				Speaker_AV1 PC COM	55
S9				Scartout_SIF	88
				Scartout_EXCEPTSIF	88
				Delay Enable	OFF	to active or inactive sound delay mode
	Sound Delay
				Delay value	0	to assign delay value
				Apply		to apply the changed value about sound delay
	Dimming Control				254	to control the dimming value of the panel
				IFAGC NORMAL	18	to adjust IF AGC value about signal except
	IFAGC Contronl					SECAM L/L’
				IFAGC L or L’	16	to adjust IF AGC value about SECAM L/L’
	Frequency				000 MHz	to display the frequency of the present signal
	Gamma				OFF	to active or inactive gamma function
	DLC				OFF	to active or inactive DLC function
	Memory Recall					to reset EEPROM
	Oper Mode				NOR-DEB-DW	Normal Mode-Debug Mode-Data Writing Mode
S10	Don’t use
S11	Version information					to display the date of the firm ware
S12	Factory Mode					to initialize TV and make TV standby mode
						¡White Balance items(S8) are not initialized

-24-

SERVICE MODE

5-1-2.Description of SERVICE MODE ITEM A.S1(1) : Heat-Run Key

B.S2(2) : Gumi Channel Map Write C.S3(3) : Volume Test

=> This key can check sound D.S4(4) : EDIT WRITE

=> Using this key, you can up data EDID data. (but the “shunt”must be connected, and only executed in the Factory.)

E.S5(5) : PANEL TEST

=> Using this key, you can test problem of PANEL, as confirm white pattern red pattern, blue pattern, green pattern.

F.S6(6) : PICTURE TEST

=> Using this key, you can test brightness, contrast and color. G.S7(7): DEMPOL CHANNEL MAP WRITE

H.S8(8) : White Balance adjustment

=> Using this key, you can adjust White balance. I.S9(9) : Device control

=> This key only use for R&D. J.S10(10) : Opion key

=> Using this key, you can adjust SSC, Dimming, panel Type and etc. K.S11(11) : Version key

=>Using this key, you can identify the information of the S/W of the set. L.S12(SLEEP ) : Shipping key

=> Using this key, you can up at shipping mode.

-25-

6. Main PCBs Trouble Diagnosis

6-1.Main PCB Trouble Diagnosis

6-1-1.Common checking process when “No signal of Noraster” No signal : OSD is work but no images are displying

No raster : OSD as well as images in not working

Check start

Does No signal	N
screen appear?

Y

Is the signal	N		Check the connection
			of Jack
input Jack properly?
			(LCD and AV device)

Y

	Does input source	N
				Check AV device
	(AV device) work?

Y

N

Is input selection

Check input mode

in the Correct mode?

Y

Replace Main PCB and/or Sub PCB

Is a weak	N
Discharge detected
in the screen?

Y

N

Is LVDS connection Correctly connected?

Y

N

Is waveform of CLK in the Main PCB

Normal?

Y

Check other PCBs and connectors

1.Check AC connection 2.Check Power S/W ON 3.Check other PCBs

Check LVD connection Panel & P3 of Main PCB

Replace Main PCB and/or Sub PCB

-26-

Main PCBs Trouble Diagnosis

A.When “No signal”in CVBS(RF, AV) 1)First check if other inputs are working

=>if other inputs are not working, replace MAIN PCB

2)Checking waveforms with Color Bar Pattern(Using the oscilloscope) - Main TP(RF) : R203

- Main TP(RF) : R177

-27-

Main PCBs Trouble Diagnosis

B.When “No signal”in Y/C signal(S-Video) 1)First check if other inputs are working

=>if other inputs are not working, replace MAIN PCB

2)Checking waveforms with Color Bar Pattern(Using the oscilloscope) - Main TP(Y signal) : R199

- Main TP(C signal) : R173

-28-

Main PCBs Trouble Diagnosis

C.When “No signal”in Y/Pb/Pr signal(Component) 1)First check if other inputs are working

=>if other inputs are not working, replace MAIN PCB

2)Checking waveforms with Color Bar Pattern(Using the oscilloscope) - Main TP(COMP1- Y) : R171

- Main TP(COMP1-Pb) : R193

-29-

Main PCBs Trouble Diagnosis

- Main TP(COMP1-Pr) : R167

D.When “No signal”in PC

1)First check if other inputs are working

=>if other inputs are not working, replace MAIN PCB

2)Checking waveforms with Color Bar Pattern(Using the oscilloscope) - Main TP(R signal) : R150

-30-