CS, CLK and DATA perform the communication between VFD
driver and CPU.
VFD driver also keep scanning the keyboard (front panel
buttons) periodically to detect the user command and transfer
to CPU for performing the action.
Remote Control Isolation Circuit And Cpu Interface At
To CPU on front Board
Figure 9-24 Remote Control Isolation
The two transistors in the circuit are used for isolation of remote
signal. Infrared signal for remote receiver will be send to the
CPU (front panel board) for command processing. When the
set is in standby condition, no voltage is supply to the Decoder
IC; the output voltage at IR receiver is in low output condition,
the CPU (front panel) will not receive the IR signal from remote
handset without the isolation circuit.
In the following diagram shows that a high stage voltage will be
send out from U302 to turn off all supply other than the VCC.
Figure 9-25 U302 Control Diagram
Digital Audio Output Circuit
Figure 9-26 Digital Audio Out
SHORT£ 1000 OHM£©
Digital audios are source from the decoder (ESS60x8) chip set
that is the serial data stream in SPDIF format. There are two
form of digital audio output, one of them is coaxial, and while
the other one is optical. The optical terminal is an electrical to
optical signal converter.
Trouble Shooting On The Disc Loader Of
The Disc loader in DVD580M is of Slot-Entrance-type with a
high accuracy of the mechanical structure and a good
shockproof capability. The loader in the DVD player is not
belonging to component serviceable part. Hence, it is
necessary to clarify if any fault condition of the player is caused
by the loader, before replacing the loader.
In the DVD system, the linkage between loader and the
decoder board is the ATAPI standard. The loader is a stand-
alone system, the servo control board of the loader is
consisting all necessary device for disc reading and primary
decode, such as CPU, DSP and data memory. Once a stable
voltage is supplied to the loader, the loader itself can operate
even without connecting to the decoder board. By observing
the movement of optical assembly part and the major axis
motor will know the loader is operating. Hence, to clarify
whether the loader is in fault condition, remove the 40 pins wire
assembly and observe the movement descript above. If the
+12V and +5V supply voltage is normal by measure, and no
any movement can be obtained, the loader is faulty.
One the other hand, If the loader can operate alone, but lost it
after 40 pins connecter is reconnected, then the decoder board
or the decoder chipset itself may get faulty. In this situation,
check the circuit between the two modules (loader and decoder
board) or replace the decoder IC chipset if necessary.
The disc loader is having two type of laser pickup optical, one
for DVD disc, while the other one works for VCD or CD. If any
one type of disc (DVD or VCD / CD) dose not be identified. It
can be sure that the fault is come from the disc Loader.