SAMSUNG PN15HT
Service Manual

5 Troubleshooting

5-1-13 High Voltage Failure
No Check and replace IC401 and +12 V line.

WAVEFORMS
3 5.00 V (IC401, #28)

3

IC401 Pin 28 OSC pulse exists?

Yes No
10

Q402 Gate driving pulse exists? Yes No

Check and replace Q401.
CH1 P-P = 2.00 V CH1 RMS = 5.868 V

10 5.00 V (Q402, Gate)

11

Q402 Drain pulse exists?

Check and replace Q403 and L402.

Yes Done

CH1 P-P = 2.00 V

CH1 RMS = 7.692V

11 50.0 V (Q402, Drain)

5-1-14 ABL Failure
CH1 P-P = 50.0 V CH1 RMS = 73.7V

Input full white pattern to monitor.

IC101 Pin 22 input exists and varies with different patterns? Yes Check CN102. Yes T501 Pin 8 output exists?

No

Check and replace IC101.

No

Check and replace T501.

Yes IC201 Pin 26 output exists and varies with different patterns? Yes Done No Check and replace IC201.

PN15VT/VO PN15HT/HO

5-7