Samsung LB15VS Service Manual page 23

5 Troubleshooting
5-1-5 H_Lin. Failure
5-1-6 Invariable H_Size
IC401 Pin 28 voltage varies with
different B_DRV DAC values?
Yes
Q590 gate output duty
varies with different B_DRV
DAC values?
5-1-7 Abnormal H_Size
IC401 Pin 24 output duty
varies with different B+
offset DAC values?
Yes
Q490 collector
6
waveform is right?
Yes
Check components
around D405 and L411.
5-4
Check and Replace L441 (Fix Type)
No
Check and replace IC401.
Check some parts around
No
Q590,
Pin 14~16 of IC401.
No
Check and replace IC201,
IC401.
No
Check and replace Q411,
Q412, Q413, and Q414.
WAVEFORMS
6
1300 Vpp (Q490, Collector)
LB15VS/LB17LS/LB17KS/
LB17LT/LB17KT