17
Model No: CT-21FDS1
Version 1.0
3. Only horizontal line in the middle of the screen:
If vertical deflection circuit does not work, this kind of failure will happen. In deflection yoke, there only has horizontal sweeping, the electron beam in the CRT only moves in the horizontal orientation, so form this failure.
(While checking horizontal and vertical deflection circuit’ s failure, we have better to use an oscilloscope.)
Abnormal
Normal
Normal
Abnormal
24V
0V
Abnormal
Normal
The waveform on the pin 24 of N201
Measuring the waveform on the deflection yoke
Check C272,R279,N201
The voltage on pin 3 of N402
Check VD557, R550,V554,N402
Check N402
Measuring the waveform on pin 4 of N402
Check R908, C448, N402, N201
Measuring the waveform on pin 2 of N402
Check R442,C413,VD433,XZ411, deflection yoke
Abnormal
The deflection yoke on the CRT
