Sony FWD-50PX3 Service Manual page 105

5-1. Microcomputer
A microcomputer is mounted in IC800 (A board). It
controls the whole block. Firmware is stored in IC501,
and each setting data is stored in IC400. Two external
SDRAMs (IC502 and IC503) of 128 MB are connected for
image processing.
5-2. Input Signal Selection
A signal can be input from DVI or Option 1 as a digital
signal. An RGB/component signal can be input from the
HD15 terminal as an analog signal, and RGB/component
and composite/S-video signals can be input from Option 1/
2. The RGB/component signal from the standard HD15
terminal is received using a transistor and then input to
IC800. The RGB/YUV signal from Option is selected
using a switch and input to IC800. The signal from
standard DVI and the digital signal from Option are
selected using IC203 and input to IC800. The composite/
S-video signal from Option is selected using IC1 and input
to IC800. An HDMI audio signal is output from IC203,
converted from digital to analog using IC601, and input to
IC1. Other audio signals are also input to IC1, selected,
and output from Audio_Out and Speaker_Out terminals.
The Speaker_Out terminal enables volume control. The
Audio_Out terminal outputs an input signal directly.
5-3. Video Decoder and Filter Circuits
The composite/S-video signal input from Option is select-
ed using IC1 and input to IC800. A video decoder is
incorporated into IC800. In addition to a main path, the
video decoder has a sub-path for PIP/PAP. The main path
and sub-path have different filter circuit configuration. A
slight difference appears in the image pattern during PAP.
Picture quality is all set in this IC.
FWD-50PX3
Section 5
Circuit Description
5-4. Audio Circuit
Analog audio signals are selected using IC1, branching
into Audio Out and speaker terminals. An Audio_Out
signal is directly output from a connector. A speaker
signal is converted into a digital audio signal using IC601
and input to sound processor IC602. IC602 sets each
sound quality or volume. The input signal of IC602 is
output through an audio amplifier (IC606) from a speaker.
An HDMI audio signal is output from IC203 as a digital
audio signal. The output signal is converted into an analog
signal using IC607 and input into IC1 as in other analog
audio signals. And in audio signal output from speaker,
using memory (IC603) connected to IC602, an audio delay
value is adjusted to synchronize an image and sound.
5-5. Connection with Panel
A signal is connected with the panel using an LVDS signal
and directly output from IC800.
5-6. Network
A network function is controlled using IC1003. It internal-
ly communicates with a main microcomputer (IC800)
using an RS-232C protocol. For connection with the
outside, a network function is connected to IC1003 via
IC1000. The firmware of IC1003 is stored in IC1002 and
processed using work memory (IC1001).
5-1