Troubleshooting - Samsung PN19MT Service Manual

5 Troubleshooting

5-1 Parts Level Troubleshooting
Notes: 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 FG601, D601,
D701, Q701, IC601, and ZD601.
Yes
Repeating start?
Yes
IC601 Pin 1 waveform is right?
1
Yes
IC701 Pin 8 Voltage is right?
Yes
Operate normally?
Yes
Verify voltages.
Done.
PN19MT/MO/IO
x178/19P2
No
Check and replace D606, IC620,
D647, and D640.
No
Check and replace
D620, IC601 and IC701.
No
Check and replace ZD705, ZD706, D702,
and also check the secondary diodes.
No
Replace Main board.
WAVEFORMS
1 100 V (IC601, #1)
CH1 P-P = 100 V CH1 RMS = 350.2 V
5-1