LG Flatron L1742P - Troubleshooting Raster Issues

6. Raster
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Only for training and service purposes
LGE Internal Use Only
NO Raster
(Lamp Off)
NO
Check Scaler Output
(Main Board)
CHECK T301
NO
NO
Check Q301, Q302
Check the waveform of U301
Pin1, 15
Check the waveform of U301
Pin2, 3
NO
If waveform is no problem
Check D302~D308
Or Trouble in U303, U304
YES
CHECK
P201 Pin9
3.3V?
Check U301 Pin2
5V?
Check U301 Pin6 VSEN,
Less than 3V
Check U301 Pin12 SSTCMT,
Less than 1V
Check U303, U304
Drain waveform
YES
YES
YES
NO