Samsung LXB530, LXB550, LXB350 Troubleshooting

SyncMaster 33*TFT/53*TFT 6-1

6 Troubleshooting

Notes: 1. Before troubleshooting, setup the PC’s display as below.

• Resolution: 1024 x 768

• H-frequency: 48 kHz

• V-frequency: 60 Hz

2. If no picture appears, make sure the power cord is correctly connected.

3. Check the following circuits.

• No raster appears: Audio PCB, SMPS PCB, Main PCB (SyncMaster 330TFT/550TFT) Stand PCB, Main PCB (SyncMaster 331TFT/531TFT)

• 12V develop but no screen: Main PCB

• 12V does not develop: Audio PCB, SMPS PCB (SyncMaster 330TFT/530TFT)

Main PCB (SyncMaster 331TFT/531TFT)

4. If you push and hold the “EXIT” button for more than 5 seconds, the monitor automatically turns back to the factory preset.

6-1 No Power

Does proper DC 12 V appear at

DC jack connected to CN102?

Check Stand PCB.

Yes

Does proper DC 5 V appear at

Pin 3 of IC109?

Check F101 and IC109.

Check IC401, RL101, D110 and Q101.

Yes

6 Troubleshooting

6-2 SyncMaster 33*TFT/53*TFT

6-2 No Video

Replace IC101.

Power indicator is green

Replace IC305 or check its

related circuit.

Replace IC310 and IC311 or

check its related circuits.

Replace IC106.

Replace IC105 (seperate sync)

or IC104 (SOG).

Check IC401 and IC101.

Does the clock pulse

appear at output of

FT110, FT111, FT112?

Does the H-sync pulse appear

at Pin 94 of IC101?

Does the pulse appear at Pin 10

of IC105 or Pin 1 of IC104?

7 8 9

Does the sync pulses appear at

Pins 13 and 14 of IC110?

Does the sync pulses appear at

Pins 2 and 3 of IC110?

Replace IC110 or check its

related circuit.

18 19 20 1

Replace IC301 or check its

related circuit.

Replace LCD Panel

Do the sync pulses appear at

Pins 22, 23, 25 and 26 of IC310?

Do the sync pulses appear at Pins

2, 3, 54, 55 and 56 of IC301?

2 3 4 5 10 11 12 13 14

Do the waveforms appear at

Pins 5 and 20 of CN301?

Yes

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