Acer AC501 AC501 Monitor Service Guide - Page 17

2 .Hor. processor The H-out that come from u-P will input to the pin 15 of U401,it will be compared with the oscillator sawtooth voltage by the PLL1(pin 26) phase detect or, After that, it will be com-pared again with the fly back pulse (pin 1) by the PLL2. The PLL2 detector thus compensates for the delay in the external horizontal deflection circuit by adjusting the phase of the HDRV(pin 7) output pulse. 3 Vert. Pre-amp Vertical oscillator will be trigged by V-out (pin 14) .It is available to get sawtooth waveform in pin 24. V-center, V-amp and V-linearity can be adjusted in pin 17, 18 and 19. The vertical output driver is come from pin 12 and 13. I-3. Verti cal Output IC U601(TDA 8172) is the vertical amplifier IC, the output pin5 connect to the YOKE .The sawtooth current float across the YOKE to make vertical deflection. Fig. 4 is the block diagram of IC TDA8172. 1. Block Diagram 17