SAMSUNG GH15LSSN_EDC Service Manual Troubleshooting
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 (GH15LS/GH15ES/GH15MS)
Does proper DC 12 V
appear at FT901, FT902
or Pin 1, 2 of CN101?
Yes
Does proper DC 3.3 V
appear at Pin 7 of CN 101?
Yes
Check IC102 and Q192.
No
Check SMPS or CN101.
No
Check SMPS.
GH15LS/GH15ES/GH15MS 4-1
4 Troubleshooting
4-2 No Video
Does the H-sync pulse
1
appear at Pin 9 of IC108?
Yes
Does the H-sync pulse
4
appear at Pin 150 of IC105?
Yes
Does the V-sync pulse
2
appeaer at Pin 30 of IC301?
Yes
Does the V-sync pulse
3
appeaer at Pin 148 of IC105?
Yes
No
No
No
No
Check CN102.
Replace IC108 or
check its related circuit.
check CN102.
Replace IC301 or
check its related circuit.
Does the clock pulse
5
appeaer at Pin 44 of IC105?
Yes
Do the pulse appeaer
6
at Pin 43 of IC105?
Yes
Does the waveforms
7
appeaer at Pin 3
and 16 of CN201?
Yes
Replace LCD Panel
No
No
Replace IC105 or
check its related circuit.
No
Replace IC251 or
check its related circuit.
4-2 GH15LS/GH15ES/GH15MS
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