Troubleshooting - Samsung PN22N Series Service Manual

5 Troubleshooting

5-1 Parts Level Troubleshooting
Notes: 1. If a picture does not appear, fully rotate the brightness and contrast controls clockwise and reinspect.
2. Check the following circuits.
• No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit.
• High voltage develops but no raster appears: Video output circuits.
• High voltage does not develop: Horizontal output circuits.
5-1-1 No Power Supply
Check and replace FH601, D601,
Q601, Q604, and IC611.
Repeating start?
No
IC611 Drain waveform is right?
5
Yes
Q601 Drain waveform is right?
2
Yes
Q604 Drain waveform is right?
4
Yes
Done.
PN22N*
Yes
Done.
No
Check and replace IC611.
No
Check IC601 and D602.
No
Check IC602 and IC603.
WAVEFORMS
2 Q601 Drain
CH1 RMS = 226.0V
4 Q604 Drain
CH1 RMS =434.4V
5 IC611 Drain
CH1 RMS = 333.2V
5-1