Vertical Scanning Section
Vertical scanning section adopted STV8172A vertical deflection booster, we use as
differential-output driver. The vertical raw-tooth wave signal sends out from pin14/15 of IC201
VDA/VDB. The two differential signal input pin 1 and 7 of STV8172A IC301. Pin2(+14v) and
Pin7(-14v) of IC301 is power supply which come from the main power transformer. Pin 6 is boost
voltage, rectified by D301. C309,C301 and R305 makes up a voltage feedback network, R306 is a
damping resistor. C306 is correction capacitor, R308 is current feedback resistor.
Fig 4. Vertical Scanning Processing Section
CRT Scanning Section
Q507,D501,D502 and D503 makes up a light eliminate circuit network. When the TV is playing
mode, +8V voltage across R533 charge for C512, Q507 is cut off. At the right of turn off the TV,
Q507 is turn-on, the current across D501, D502 and D503 send to R.G. B to discharge the
electronic quickly.
