4 Troubleshooting

4 Troubleshooting
4-1 Common Acknowledge

- If you change the interface board, be sure that the U105, U106 and U103 these three components also
changed to the new I/F board because there was program inside. If not, please re-write EDID or upload
firmware into Flash memory via VGA Cable.
- If you adjust clock and phase, please do it at the condition of Windows shut down pattern.
- If you confirm the R.G.B. color is normal or not, please do it under 16-grey scalar pattern.
- This LCM is analog interface. So if the entire screen is an abnormal color that means the problem
happen in the analog circuit part, if only some scale appears abnormal color that stand the problem
happen in the digital circuit part.
- If you check the H/V position, please use the crosshatch pattern.
- This LCM support more than 30 timing modes, if the input timing mode is out of specification, the picture
may appears abnormally.
- If brightness uneven, repairs Inverter circuit or change a new panel.
- If you find the vertical line or horizontal line lost on the screen, please change panel.

4-1
4 Troubleshooting

4-2 No Power & Power LED Off

No power

Check primary Check circuit if Check IC802,

rectifier voltage short C805, T801

Check F801, P801, D801

Check pin3 of
Check R801, R805,
IC802 voltage
R822, R823, R817
about 1V

Check pin2 of
Check R803, R807,
IC802 voltage
R824, R825
about 2V

Check pin1 of
IC802 voltage is Check R812, R816, C818
5.8V

END

4-2
 4 Troubleshooting

4-3 DC output voltage is unstable

Output Voltage Unstable

Check Vbe of Check circuit if Check ZD801, ZD802,

Q801 below short ZD803, D803, D805

Check Q801, Q802

Check reference Check pins of Check R801, R805,

voltage IC801 R822, R823, R817

Check R810, R811

Check feedback Check Vpin3-4 of

Check C815, D806, R812
circuit IC801 about 6V

Check Vpin1-2 of
IC801 about

Check C815, D806, R812

END

4-3
4 Troubleshooting

4-4 Output power is unstable

Unstable power

Check sampling Check R810, R811,

Circuit R818

Change R810, R811,

R818

Check the R pin Check the C pin

voltage of IC803 voltage of IC803 if Change IC803
about 2.5V 3V

Check R809, R808,

R814, D809

Check pin1 of
Check D806, C815
IC802 voltage is
if short
5.8V

Change D806, C815

Check pin3 of Change R801, R805,

IC802 voltage R822, R823, R817
about 1V

END

4-4
 4 Troubleshooting

4-5 Backlight can't be turned on

No backlight

Yes

No Yes
No power supply to Check the cable that from
LED lamp is OK
inverter I/F BD to P/I BD is ok

Yes

Is there 14V No No
voltage on pin 3,4 U501, U502 fail Check power supply
of T501, T502

Yes Replace U501, U502

Is there PWM No
signal on pin 4 of Check I/F BD
IC501

Yes

Is there High level No

voltage on pin4 of Check I/F BD
IC501

Yes

No
Vsense voltage
Lamp connector opened
2.9V

No

Are there PWM No

signal on pin1, IC501 failure
pin15 of IC501

Yes

Yes Yes
Pin 5 of IC501 Check R523, D504,
Feedback circuit failure
voltage is Low level R529, D507, R528, R533

Yes

Pin 5 of IC501 Yes Yes

voltage is high level IC501 protected Check D505, D506,
voltage D510, R522, R521, C520

END

4-5
4 Troubleshooting

4-6 Black Screen and backlight turn on

Black Screen

Check power No
supply: Pin1, 2 of Power Fail
CN101

Yes

Check pin34, 51, No

66, and 82 Of Check FB103 And U102
U105

Yes

Check pin32, 49, No

56, and 75 Of Check FB106 And U101
U105

Yes

Check Reset No
Check C144, R172
(pin84) Of U105

Yes

Check Crystal: No Check: X101, C153,

Pin96, Pin97 Of
C154
U105

Yes

Check CCFL- Yes Yes

Check pin5 of
Enable (pin85) of Inverter Fail
CN101
U105

No No
Check R167, Q106,
R108, R110
MCU Fail

4-6
 4 Troubleshooting

4-7 White Screen

White Screen

LVDS Cable Yes

Workmanship
Reinsert

No

Change LVDS Yes

LVDS Cable NG
Cable

No

Yes Yes
Check VLCD Is Check LVDS Panel Fail
5V? Signals

No No

Check Panel Check the HW No

Enable Of U105 Reset Of U105 Check C144 R172
(pin48) is High? pin84

No
Yes

Check R168, R105,

Q103, Q101
Check the pins Of
U105

END

4-7
4 Troubleshooting

4-8 Bad Screen

Bad Screen

LVDS Cable Yes

Workmanship
Reinsert

No

Change LVDS Yes

LVDS Cable NG
Cable

No

Check Yes Check :X101, C153,

Crystal:Pin96,97 Of
C154
U105

Yes

Check the No Check: SDO, SCZ, SCK,

communication Of
SDI, Reset
U105 and U106

Yes

Check the pins of U105

and U106

4-8
 6 Electrical Parts List

6 Electrical Parts List

-You can search for updated part codes through ITSELF web site.
URL : http://itself.sec.samsung.co.kr/
6-1 Parts List

Level Loc. No. Code No. Description & Specification Q'ty SA/SNA

0.1 M0215 BN07-00220A LCD-PANEL;CLAA170EA07Q,Matisses,6Bit,358 1

0.1 5010202070 BN81-00356A A/S-COVER,BACK;BLACK,W/DVI, LE1939,-,-,- 1
0.1 7140300053 BN82-00161A A/S MATERIAL ASSY-BEZEL(S);LE1729,-,-,-, 1

0.1 7000000002 BN82-00166A A/S MATERIAL ASSY-PCB&RIVENT;LE1729,-,-, 1

0.1 7906113000 BN82-00177A A/S MATERIAL ASSY-PCBA IF BOAR;LE1729-0E 1

0.1 7906114000 BN82-00178A A/S MATERIAL ASSY-POWER INVERT;LE1729-6E 1

0.1 7906115000 BN82-00179A A/S MATERIAL ASSY-KEYPAD BOARD;LE1729 1

6-1
6 Electrical Parts List

Memo

6-2
 9 Schematic Diagrams

9 Schematic Diagrams
- This Document can not be used without Samsung s authorization.
9-1 DC-DC

9-1
9 Schematic Diagrams

9-2 INPUT

9-2
 9 Schematic Diagrams

9-3 TSUM16AL

9-3
9 Schematic Diagrams

9-4 POWER

9-4
 9 Schematic Diagrams

9-5 INVERTER

9-5
9 Schematic Diagrams

9-6 KEYPAD

9-6