Samsung UN19D4003BD, UN26D4003BD, UN32D4003BD, UN22D5003BF, LN32D40*E*D Service Manual

4. Troubleshooting

4. Troubleshooting

4-1. Troubleshooting

4-1-1. Previous check

1.Check the various cable connections first.

•Check to see if there is a burnt or damaged cable.

•Check to see if there is a disconnected or loose cable connection.

•Check to see if the cables are connected according to the connection diagram.

2.Check the power input to the Main Board.

				14p cable			LVDS Cable												Power Assy
															14p cable
Power Assy							Main Assy					Main Assy			LVDS Cable
	Speaker							Speaker				Speaker			T-CON					Speaker
Main Assy (CN202 / 204)						Power Assy (CMN801)					Main Assy (CN201 / 203)						Power Assy (CMN801)
1		B5V	2	SW_PW	1		B5V	2	SW_PW	1		B5V	2		SW_PW	1			B5V		2	SW_PW
3		B5V	4	A5V	3		B5V	4	A5V	3		B5V	4		A5V	3			B5V		4	A5V
5		GND	6	GND	5		GND	6	GND	5		GND	6		GND	5			GND		6	GND
7		B12VS	8	GND	7		B12VS	8	GND	7		B12VS	8		GND	7			B12VS		8	GND
9		B12VS	10	SW_INV	9		B12VS	10	SW_INV	9		B12VS	10		SW_INV	9			B12VS		10	SW_INV
11		B13V	12	NC	11		B13V	12	NC	11		B13V	12		NC	11			B13V		12	NC
13		B13V	14	DMM	13		B13V	14	DMM	13		B13V	14		DMM	13			B13V		14	DMM

4-1

4. Troubleshooting

4-1-2. How to check fault symptom

No Power

	-- The LEDs on the front panel do not work when connecting the power cord.
Symptom	-- The SMPS relay does not work when connecting the power cord.
	-- The units appears to be dead.
	The IP relay or the LEDs on the front panel does not work when connecting the power cord if the
	cables are improperly connected or the Main Board or SMPS is not functioning.
	In this case, check the following:
Major	-- Check the internal cable connection status inside the unit.
checkpoints	-- Check the fuses of each part.
	-- Check the output voltage of SMPS.
	-- Replace the Main Board.
				No
		Power indicator LED on?					Check an AC power connection.
			Yes
				No
		Check the 14P power cable					Change 14p power cable or SMPS.
			Yes
		Check ‘Stand-By 5V’ DC5V appear at		No
		BD207(middle)/BD214(small)?
			Yes				Change SMPS.
		Check ‘Power input of Main Assy’ ?		No
		DC B13V, B5V appear at BD209(M)/BD221(S)
		(B13V), BD208, BD213(M)/BD210, 212(S)(B5V)?
			Yes
		Check ‘Power of main IC(B1.1V)’		No
		Check ‘Power of DDR IC(B1.9V)’					Change the Main Assy.
Diagnostics		appear at L201 (B1.1V)
		BD1012 (B1.9V) ?
			Yes
				No
		Check ‘Power of LVDS (13V)’ appear at					Change the LVDS cable.
		LVDS connector Pin #1~5 of T-con b’d?
			Yes
				No
		Does proper DC B13V appear at F1 of					Change the T-con b’d.
		T-con b’d?
			Yes
		Please, Contact tech support.

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

4-2

4. Troubleshooting

Location (Main) - TOP

Location (Main) - T-CON

4-3

4. Troubleshooting

No video_HDMI1, 2 - Digital signal

	Symptom	--	Audio is normal but no picture is displayed on the screen.
	Major	--	Check the HDMI source.
		--	Check the HDMI switch, Check the Chelsea.
	checkpoints
		-- This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
						No
				Power indicator LED is off.					Check a set in the 'Stand-by mode'.
				Lamp(Backlight) on, no video ?
					Yes
				check the Self Diagnosis		No			Check external devices and
				(SupportSelf DiagnosisPicture Test)
									connections.
				Dose the promblem still exist self diagnosis ?
					Yes
				Check the HDMI source and		No			Input the HDMI signal properly.
				check the connection of HDMI cable ?
					Yes
				Does the signal appear at					Check CN502, CN503.
				CN602 (Pin#12 , #7 )(HDMI1)		No
									Check HDMI cable.
				CN601 (Pin#12 , #7 )(HDMI2)
									Change the Main Assy.
				(HDMI RX_Clk , RX_Data) ?
					Yes
				Does the digital data appear at		No			Check IC1001 (X5N)
				TP-E_TXCLK+, E_TXCLK- ,
									Change the Main Assy.
	Diagnostics			O_TXCLK+, O_TXCLK-?
					Yes
				Check the LVDS cable ?		No
				Check the T-Con B’d ?					Please, Contact Tech support.
				Replace the LCD panel ?

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

4-4

4. Troubleshooting

Location (Main) - TOP

4-5

4. Troubleshooting

WAVEFORMS

HDMI input (RX_Data, RX_Clk)

LVDS output

4-6

4. Troubleshooting

No Video_Tuner - CVBS

	Symptom	-- Audio is normal but no picture is displayed on the screen.
	Major	-- Check the Tuner CVBS source.
		-- Check the Tuner, Check the Chelsea.
	checkpoints
		-- This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
					No
			Power indicator LED is off.				Check a set in the 'Stand-by mode'
			Lamp(Backlight) on, no video ?
				Yes
			Check the RF source and		No		Input the RF source properly.
			check the connection of RF cable ?
				Yes
			check the Self Diagnosis		No		Check external devices and
			(SupportSelf DiagnosisPicture Test)
							connections.
			Dose the promblem still exist self diagnosis ?
				Yes
			Does the DC B1.8V B3.3V		No		Change the Main Assy.
			appear at #3, #5 Pin of Tuner ?
				Yes
			Check the CVBS data		No		Change the Main Assy.
			at #15 Pin of Tuner ?
				Yes	No
			Does the digital data appear at				Check IC1001 (X5N).
			TP-E_TXCLK+, E_TXCLK- ,
							Change the Main Assy.
	Diagnostics		O_TXCLK+, O_TXCLK- ?
				Yes
			Check the LVDS cable ?
			Check the T-Con B’d ?		No		Please, Contact Tech support.
			Replace the LCD panel ?

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

4-7

4. Troubleshooting

Location (Main) - TOP

4-8

4. Troubleshooting

WAVEFORMS

LVDS output

4-9

4. Troubleshooting

No Video_Tuner DTV

	Symptom	--	Audio is normal but no picture is displayed on the screen.
	Major	--	Check the DTV source.
		-- Check the Tuner, Check the Chelsea.
	checkpoints
		-- This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
						No
				Power indicator LED is off.				Check a set in the 'Stand-by mode'
				Lamp(Backlight) on, no video ?
					Yes	No
				Check the connection of RF cable ?				Input the RF source properly.
					Yes
				check the Self Diagnosis		No		Check external devices and
				(SupportSelf DiagnosisPicture Test)
								connections.
				Dose the promblem still exist self diagnosis ?
					Yes	No
				Check the 'signal strength' in Self Diagnosis				Check the D-TV source.
				menu Strength is enough ?
					Yes
				Does the DC B1.8V B3.3V		No		Change the Main Assy.
				appear at #3, #5 Pin of Tuner ?
					Yes
				Check the DTV data(DIF+, DIF-)		No		Change the Main Assy.
	Diagnostics			appear at #11, #10 Pin of Tuner ?
					Yes
				Does the digital data appear at		No		Check IC1001 (X5)
				TP-E_TXCLK+, E_TXCLK- ,
								Change the Main Assy.
				O_TXCLK+, O_TXCLK- ?
					Yes
				Check the LVDS cable ?
				Check the T-Con B'd ?		No		Please, Contact Tech support.
				Replace the LCD panel ?

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

4-10

4. Troubleshooting

Location (Main) - TOP

4-11

4. Troubleshooting

WAVEFORMS

LVDS output

4-12