Samsung CN15LSBPN, RN15LS-LO Troubleshooting

SyncMaster 570STFT/580STFT 4-1

4 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

• 12V develop but no screen: Main PCB

• 12V does not develop: Audio PCB, SMPS PCB

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

4-1 No Power

Does proper DC 12 V appear at

DC jack connected to CN101?

Check SMPS or CN809.

Yes

Does proper DC 5 V appear at

Pin 4 of IC101?

Check FT104 and IC101.

Check IC102, IC103, IC104, Q101 or

IC901.

Yes

4 Troubleshooting

4-2 SyncMaster 570STFT/580STFT

4-2 No Video

Replace IC201.

Power indicator is green

Replace IC304 and IC305 or check

its related circuit.

Replace IC304 and IC305 or

check its related circuits.

Replace IC106.

Replace IC104 (SOG)

or check R102 and Pin 13 of

CN201

Check IC201 and IC401.

Does the clock pulse

appear at Pin 81, 83 and 84 of

IC201?

Does the H-sync pulse appear

at Pin 94 of IC201?

Does the pulse appear at Pin 9

of IC106 or Pin 1 of IC105?

5 6 7

Does the sync pulses appear at

Pins 20 and 22 of IC303?

Does the sync pulses appear at

Pins 34 and 39 of IC303?

Replace IC303 or check its

related circuit.

9 10 11 1

Replace IC301 or check its

related circuit.

Replace LCD Panel

Do the sync pulses appear at

Pins 25 and 26 of IC304?

Do the sync pulses appear at Pins

141 and 142 of IC301?

2 3 8

Do the waveforms appear at

Pins 1 and 16 of CN301?

Yes

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