Zenith DVB318, Service Manual

Page: 20 / 68

3-11
IC202
IC201
Driver IC
Pin23
Pin24
Pin133 Pick-up
F-
F+
Pin8
Pin9
FACT
FACT is made from focus error signal at DSP(IC202) and is input to IC201.
And then FACT is converted into F - and F+ in IC201.
Finally, they are sent to pick - up to control a focus actuator.
IC202
pin33
IC201
pin8
IC201
pin9
A signal flow for FACT The waveform of FACT, F- and F+
20. Focus Drive signal(FACT)
MRESET signal is output from front µ-COM when power is on, so IC501 is initialized.
And those(front µ-COM and IC501) communicate each other through SCKO, TXDO, RXDO signals
Waveforms display each signal when power on and after power on
IC501
pin207
IC501
pin1
IC501
pin208
IC501
pin124
SCKO
TXDO
RXDO
MRESET
IC501
pin207
IC501
pin1
IC501
pin208
IC501
pin124
The waveform when power is on The waveform after power on
21. Signals for Front micom