Samsung CN15MSAPN, CN15MSAAN, CN15MSAPSP Troubleshooting
SyncMaster 570B TFT / 580B TFT 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 (CN15MSS/MOS)
Does proper DC 12 V appear at
DC jack connected to CN101?
Check SMPS or CN809.
Yes
No
Does proper DC 3.3 V appear at
Pin 4 of IC104?
Check IC104.
Check IC102, IC104, Q101 or
IC105, IC106
Yes
No
2
IC251 #31
CH1 RMS= 2.12V
3
IC133 #31
CH1 RMS= 2.12V
4
IC182 #94
CH1 RMS = 3.5V
5
IC182 #9
CH1 RMS =3.1V
6
IC203 #1
CH1 RMS =4.56V
7
IC251 #141
CH1 RMS =2.3V
1
IC251 #30
CH1 RMS= 2.8V
WAVEFORMS
4 Troubleshooting
4-2 SyncMaster 570B TFT / 580B TFT
4-2 No Video (CN15MSS/MOS)
Replace IC133.
Power indicator is green
Replace IC251 or check
its related circuit.
Replace IC182.
Replace IC181(SOG)
or check R181 and PIN 13 of
CN102
No
Does the clock pulse
appear at Pin 84 of
IC133?
Does the H-sync pulse appear
at Pin 94 of IC133?
Does the pulse appear at Pin 9
of IC182 or Pin 1 of IC181?
5
Replace IC203 or check its
related circuit.
Replace IC251 or check
its related circuit.
No
Do the sync pulses appear at
Pins 30 and 31 of IC251?
Do the sync pulses appear at
Pins 70 of IC203?
6
Yes
Yes
Yes
Yes
Yes
No
No
No
3
4
21
Do the waveforms appeaer at
Pins 1 and 16 of CN251?
7
Replace LCD Panel
Yes
No
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