Samsung TXT3093WHX Service Manual page 87

Troubleshooting
6-4-2 Troubleshooting Main Board
■ Countermeasures by Deflection Types
1. The screen is blank and only the relay repeats close and open when turning the power on.
▶ This happens when the vertical voltage or vertical signal is not supplied, and because the Micom operates for 5 to 10
seconds and then turns the power off by force as it cannot detect the vertical signal.
2. CHECK POINT
- Check that the vertical output voltage is measured in the FBT terminal.
→ VCC (+) : 18.5V
VCC (-) : 18.5V
▶ If you cannot measure the output voltage, check that the collector voltage of the horizontal TR is 1360V.
If the voltage is measured, the problem is a defect in the FBT unit.
(When you don't have an oscilloscope, and you can hear the high-voltage sound, you can determine that the horizontal TR
is normal.)
- Is the vertical input waveform output from the CXA2165 Chroma IC?
....... Input Wave Form: Weak
▶ If the signal is not measured, check the CXA2165 VCC power voltage ====> 9V
3. Check if 15V is measured at the SMPS Transformer.
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