Philips DVD 580M Service Manual Download Page 50

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Circuit description

EN 50

DVD580M

Figure 9-15 SDRAM Memory

SDRAM is dynamic type memory; beside the clock generator,
it is also containing Row address, Column address buses, data
buses, and some other control port such as Chip enable, Write
enable.
In DVD580M, SDRAM is used as the video and Audio data
buffer, data storage, and renew. The data store in SDRAM will
be lost when supply voltage is OFF.
SDRAM has its own data access time requirement. In
DVD580M, the SDRAM with -7 specification is applied, any
defected SDRAM should be replaced with the same model or
Video mosaics and Color batch will appear on screen.

Audio Digital To Analogue Converter

Figure 9-16 Audio DAC

Audio digital to Analogue converter (DAC) is using the I2S bus
as data transfer interface. It is consisting of MCLK operation
clock and BCK bit clock, (LRCK) Left Right clock, audio data
(TSD0, TSD1, TSD2) and Analogue audio output. Also some of
the control port for internal function setup.

When measuring on the DAC, all three data bus will carry data
during multi channels sound is to be decoding such as Dolby
digital or DTS format. When decoding two channels stereo
sound, only TSD0 will carry signal.
Pins 12, 13, 14 of the DAC are the internal function setup
control pins.
MCLK, BCK, LRCK, and TSD0, TSD1, TSD2 are output from
the decoder (U1), the DAC could be faulty if no any output from
the 5.1 Channel terminals above.
Under the normal playback condition, the pin13 and 14 should
be +3.3V and the pin12 should be 0v.

Video Filter Network And Driving Circuit

Figure 9-17 Video Filter Network

Video signal output from the Digital decoder (ESS60x8) will to
be input into the filter network before further output to display
device in order to reduce the high frequency component
imposed on the Video signal. The video circuit in the above
figure is consisting of the low pass filter and buffer amplifier.
When there is no video signal output from any one of the
connecting terminals of player such as CVBS, S-video, and Y-
Pr-Pb. One of the corresponding buffer amplifiers could be
faulty.
It is because of the DVD580M has to support multiple video
output format, but only four output channels from ESS 60x8 are
to be provided, hence either S-video or Component video will
be selected once at a time as the output format instead of both.
During the practical use, the user setup menu should
correspond to the output video terminal.
The user may be selecting the video format in the way that
differs from their desire, which cause wrong output from the
terminal. Check the setting before further service work.

Karaoke mixer

Figure 9-18 Karaoke Mixer

The karaoke board is installed on the same board of power
supply unit due to the limited space in DVD580M. The main
function of the board is to create an echo effect at the
Microphone input. Adjust the circuit parameters at Pin 13 ~ 16
of U203 can adjust the frequency response, the ratio

MA1

MA6

MA8

MA11

MA4

MA7

32/64MBIT SDRAM

MA0

MA10

VCC33

MA5

4Mx16 SDRAM (9ns)