Samsung SyncMaster 320TFT Service Manual page 24

6 Troubleshooting
6-3 No Video of Alternate Vertical Line
One or more even or odd vertical lines do not display.
Does the waveform appear
6
at Pin 20 of CN301?
Yes
Replace LCD panel.
6-4 No OSD
There is video but no OSD.
While pushing a front control
15 button does any pulse appear
at Pin 12 of IC307?
Yes
Replace IC308.
6-5 User Controls Don't Work
Does the DC level change at
Pins 11 and 12 of IC401 when you
push the front panel button?
Yes
Go to 6-4 No OSD Display.
6-4
No
Replace IC311 or check its
related circuit.
No
Do sync signals appear at Pins 5
16
and 10 of IC307?
17
Replace IC307 or check its
related circuit.
Check IC306 and related circuits.
No
Check the buttons.
(SW861 ~ SW866)
No
Yes
SyncMaster 320TFT/520TFT
WAVEFORMS
6 CN301 #5~20
CH1 RMS = 1.18 V
WAVEFORMS
15 IC307 #12
CH1 RMS = 2.2 V
IC307 #5
16
CH1 RMS = 1.7 V
17 IC307 #10
CH1 RMS = 4.3 V