SAMSUNG TFT-LCD 933HD (LS19CFE) - Troubleshooting

4. Troubleshooting

4. Troubleshooting 4-1. First Checklist Checklist for Troubleshooting 1. Check the various cable connections rst. - Check to see if there is a burnt or damaged cable. - Check to see if there is a disconnected cable connection or a connection is too loose. - Check to see if the cables are connected according to the connection diagram. 2. Check the power input to the Main Board. 3. Check the following circuits. • No raster appears: Function PBA, Main PBA, I/P PBA • 55V develop but no screen: Main PBA • 5V does not develop: I/P PBA 4. Check the voltage in and out between the IP↔ Main Board, between the IP↔ Panel, and between the Main LV LVDS DS Boards.

4-1

4. Troubleshooting

4-2. No Power  Symp Sy mpto tom m

Major  checkpoints

- Th Thou ough gh th the e pow power er sw swti tich ch on on,, the the LE LED D pow power er of offf and and th the e scr scree een n is is bl blan ank. k. - Check Power cable. - Check whether the Lamp connector is connected correctly to the IP IP.. - Check whether the power cable is connected correctly to the MAIN. - Check whether the Function cable is connected correctly to the MAIN.

C1109 CN1001

Diagnostics

LAMP off, power indicator  LED red color?

No

Check a connection a power cable.

No

Change a Assy PCB Power.

No

Change a Assy PCB Power.

No

Check IC1013, IC1005. Change a main PBA.

No

Check a other function.(No picture part) Replace a lcd panel.

Yes Does proper DC 13V appear  at DC5V DC5 V. Yes Does proper DC13V appear  at C1004? Yes Does proper DC3.3V DC3.3V,, 1.2v appear  at C1109? Yes A power is supplied to set?

Caut Ca utio ion n

4-2

Make Ma ke su sure re to to disc discon onne nect ct th the e powe powerr befo before re wor worki king ng on the the IP IP boa board rd..

4. Troubleshooting

4-2-1. Circuit diagrams when the power does not turn on on

R1301

1

1/10W 2

PWM_DIMMING_OUT

0OHM

B5V CN1001       1

      1      D      N       G      M

A13V 1 2 1 3 1 4 5 6 7 8 9

1:PWM 2:13V/0.65A 3:GND 4:GND 5:GND 6:5.1V/3.0A 7:5.1V/3.0A 8:A-DIMMING 9:ON/OFF

R1001_DE

4.7KOHM 1 1

1

      2

A5V 1 1

1 1

2

R1002 0OHM

R1031 4.7KOHM

1

2

B5V 1

      2

      1       2      D      N       G      M

      1       3

CN_SMD_S_009

C1001_22       2

      1

B

KTC3875S-Y

2 2

1

      4       0       0       1       2      R

1UF

      1

      1

C1005

100UF 6.3V       2

SW_INVERTER

E

     M      H       O       0

FGND

C

Q1005

C1004

100NF 25V

      2

      0      F       0      U     V       1       5       C       0       0       2       1

      3       0       0       1       C

      2

     F      N      V       0       0       0       5       1

      1

      2

R1032 4.7KOHM

      1

FGND

FGND

L:INVERTER ON H:INVERTER OFF

FGND

B3.3V_DTV B5V

B3.3VD

A5V       2

BD1022 C1107 1UF 10V

HIGH:ON LOW:OFF

R1040 100KOHM 1/10W

IC1023 1 2 3 4

5A (MAX)

BEAD_CHIP

SI4435BDY-T1-E3

IC1013

TP1002

8 7 6 5

C1120 100NF 25V

      1

IN

OUT GND

C1110 100UF 6.3V

TP1001 POWER_ON

R1030 10KOHM 1/10W B

C E

FGND

FGND

3       1

      2

      2

R1043 10KOHM 1/10W

      1

AP1084K33A

1

     P       4      I      H       3      C _      0      D       1      A      E     D      B B

C1112 100NF 25V

C1109 100UF 6.3V

      2

FGND

FGND

FGND

Q1006 2SC2412K-Q

FGND

4-3

4. Troubleshooting

4-3. No Video (Analog PC) Symp Sy mpto tom m

Major  checkpoints

- Th Thou ough gh th the e LED LED po powe werr tur turns ns on on,, the the sc scre reen en is bl blan ank k whe when n con conne nect ctin ing g the the VG VGA A ca cabl ble. e. - Even though the LED power turns on, the screen is blank when connecting the VGA cable. - Check the D-sub cable connections. - Check whether the LVDS cable is connected correctly to the panel. - Check whether the lamp connector of the panel is connected correctly to the IP board.

RA5008 RA5009 RA5010 RA5011 RA5012

IC5002

R3020 R3021 R3022

Diagnostics

Power Indicator is off. Lamp on, no video. Yes Check a PC source and check the connection of DSUB cable?

No

Input a analog PC signal and connected cable(DPMS).

No

PC cable. Change a PC cable. Change a main PCB ass’y.

No

Check IC5002. Change a main PBA.

No

Please, Call to Samsung Co. LTD.

Yes

① Does the sigmal appear at R3020, R3021,R3022? Yes Does the digital data appear at the output of RA5008~RA5012? Yes Check a LVDS cable? Replace a lcd panel? Caut Ca utio ion n

4-4

Make Ma ke su sure re to to disc discon onne nect ct th the e powe powerr befo before re wor worki king ng on the the IP IP boa board rd..