AC501 Monitor Service Guide
Page 15
H. Block Diagram 15 Then Q981, Q982 turn on R983 which comes from u-p to degauss coil. Degaussing CKT The DEGU signal which through R981, R982 is high, Q950 will be lower at 0.2V and shut down the U901 and power. When DEGU is below 4.3V. H-1. Under Voltage Protection When the line input voltage is below 75~85Vac range, the DC voltage on , the U901 pin3 immediately be saturated to make RL901 working, AC line provides a degaussing current to control degauss coil act or not. G.
H. Block Diagram 15 Then Q981, Q982 turn on R983 which comes from u-p to degauss coil. Degaussing CKT The DEGU signal which through R981, R982 is high, Q950 will be lower at 0.2V and shut down the U901 and power. When DEGU is below 4.3V. H-1. Under Voltage Protection When the line input voltage is below 75~85Vac range, the DC voltage on , the U901 pin3 immediately be saturated to make RL901 working, AC line provides a degaussing current to control degauss coil act or not. G.
AC501 Monitor Service Guide
Page 16
I -1. Processor & Vert. Deflection I . I-2. Hor. Pre-Amp Fig. 3 is the block diagram of IC TDA4858. 1 .Block Diagram 16 Sync Rpocessor H-sync & V-sync or H+V input to U2(u-P), t hen u-P output t he H-out & V-out to U401(TDA4858).
I -1. Processor & Vert. Deflection I . I-2. Hor. Pre-Amp Fig. 3 is the block diagram of IC TDA4858. 1 .Block Diagram 16 Sync Rpocessor H-sync & V-sync or H+V input to U2(u-P), t hen u-P output t he H-out & V-out to U401(TDA4858).
AC501 Monitor Service Guide
Page 17
2 .Hor. The vertical output driver is available to get sawtooth waveform in pin 17, 18 and 19. Block Diagram 17 processor The H-out that , it will be com-pared again with the fly back pulse (pin 1) by V-out (pin 14) .It is come from ...(pin 26) phase detect or, After that come from u-P will input to make vertical deflection. Verti cal Output IC U601(TDA 8172) is the block diagram of IC TDA8172. 1. Pre-amp Vertical oscillator will be trigged by the PLL2. I-3. Fig. 4 is the vertical amplifier IC, the output pin5 connect to the...
2 .Hor. The vertical output driver is available to get sawtooth waveform in pin 17, 18 and 19. Block Diagram 17 processor The H-out that , it will be com-pared again with the fly back pulse (pin 1) by V-out (pin 14) .It is come from ...(pin 26) phase detect or, After that come from u-P will input to make vertical deflection. Verti cal Output IC U601(TDA 8172) is the block diagram of IC TDA8172. 1. Pre-amp Vertical oscillator will be trigged by the PLL2. I-3. Fig. 4 is the vertical amplifier IC, the output pin5 connect to the...
AC501 Monitor Service Guide
Page 18
... is about 24.7KV for CRT is U301 (KA2143B). Video output signal add to 4~5Vp. Video PRE. The video pre-amp IC is the block diagram. The WHITE BALANCE and CONTRAST shall be adjusted by the output pwm of U301. The DC bias is 0.7Vpp, then pre-amp IC U301 amplify... AC coupling. Video AMPLIFIER The video amplifier is U303 (LM2439), it convert to the secondary of IC U302. 18 The input signal is the block diagram. Video output signal add to 4~5Vpp. Hf Cs Hf < 40K C805 + C804 + C814 Hf < 58.5K C804 + C805 Hf > 58.5K C804 I -5. Video PRE...
... is about 24.7KV for CRT is U301 (KA2143B). Video output signal add to 4~5Vp. Video PRE. The video pre-amp IC is the block diagram. The WHITE BALANCE and CONTRAST shall be adjusted by the output pwm of U301. The DC bias is 0.7Vpp, then pre-amp IC U301 amplify... AC coupling. Video AMPLIFIER The video amplifier is U303 (LM2439), it convert to the secondary of IC U302. 18 The input signal is the block diagram. Video output signal add to 4~5Vpp. Hf Cs Hf < 40K C805 + C804 + C814 Hf < 58.5K C804 + C805 Hf > 58.5K C804 I -5. Video PRE...