SAMSUNG AQ17KS
Service Manual

5 Troubleshooting

5-1-13 High Voltage Failure WAVEFORMS
3

IC401 Pin 6 OSC pulse exists?

No

Check and replace IC401 and +12 V line.

3 2.00 V (IC401, #6)

Yes No
10

Q402 Gate driving pulse exists?

Check and replace Q401 and Q423.

Yes
11

CH1 P-P = 2.00 V CH1 RMS = 5.868 V

Q402 Drain pulse exists?

No

Check and replace D401, Q403 and L402.

10 2.00 V (Q402, Gate)

Yes Done
CH1 P-P = 2.00 V CH1 RMS = 7.692V

5-1-14 ABL Failure

11 50.0 V (Q402, Drain)

Input full white pattern to monitor.

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

No

Check and replace IC101.

CH1 P-P = 50.0 V CH1 RMS = 73.7V

T501 Pin 8 output exists?

No

Check and replace T501.

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

AQ17KS

5-7