Samsung PN19LT/LO, Service Manual

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PN19LT/LO/JT/JO 5-1
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.
• 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 IC601, IC701,
Q702, and Q703.
Check and replace FH1, D601,
D701, and Q701.
Done.
Yes
Repeating start?
Check and replace D606.
No
Yes
IC601 Pin 1 waveform is right?
Check and replace D614, IC601,
Q602, and ZD601.
Check and replace IC201, IC301,
IC401, Q402, and Q404.
Yes
No
C609 Voltage is 13 V ± 0.5V?
Replace Main board.
Yes
No
No
Operate normally?
Yes
Verify voltages.
WAVEFORMS
1
1 100 V (IC601, #1)
CH1 P-P = 100 V CH1 RMS = 350.2 V
Chirping noise exists?
No