Samsung PN15VT / VO Service Manual page 21

5 Troubleshooting
5-1-5 H_Lin. Failure
IC201 Pin 21 voltage varies with
different H_Lin. DAC values?
Yes
IC603 Pin 14 voltage varies with
different H_Lin. DAC values?
Yes
Check Q412, Q413 and T402.
5-1-6 Invariable H_Size
IC401 Pin 28 voltage varies with
different B_OUT DAC values?
Yes
Q402 Gate output duty varies with
different B_OUT DAC values?
5-1-7 Abnormal H_Size
IC401 Pin 24 output duty
varies with different B+ offset
DAC values?
Yes
Q408 Collector waveform is
6
right?
Yes
Check some parts
around D409 and L401.
5-4
No
Replace IC201.
No
Check +13 V_1, Coil_5 V line.
Check some parts around IC603.
No
Check and replace IC401.
No
Check some parts around Q402,
IC401 Pin 4 ~ 6.
No
Check and replace IC201.
No
Check and replace Q405,
Q406, Q407, and Q408.
WAVEFORMS
5.00 V (Q408, Collector)
6
PN15VT/VO
PN15HT/HO