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In terms of the optical pickups, which read signals, a twin pickup system has been adopted for reading CDs (wavelength: 780nm) and

SACDs (wavelength: 650nm). Although these two optical blocks are unified, their circuit operations are independent, so that if there is
trouble with one, the other will still operate with no problem.

At the base of the optical block, there are two soldered short lands for preventing damage from static electricity. When replacing the

optical block, a flexible board must be connected to the connector and the soldering removed.

A stationary optical mechanism used in high-quality CD players and the like was adopted. The spindle motor, which chucks the disc,

moves horizontally as the disc is fed. This mechanism reduces servo current fluctuations and thus improves playback.

Disc chucking is a manual process in which the stabilizer is placed on top of the disc. As the stabilizer has been made specially for this

model, stabilizers from other CD players cannot be used.

When transporting the set or placing it in long-term storage, make sure to remove the stabilizer from inside it.
As the stabilizer is fairly heavy, if the unit is subjected to shock without releasing the chucking, it could damage the spindle motor’s
shaft. In addition, leaving the stabilizer on top of the spindle motor for a long time could negatively affect the rubber on the chucking
plate.
If a power supply problem prevents the loading panel from opening, remove the top board, rotate the loading motor by hand, and
remove the stabilizer. When removing the top board, do it so that the stabilizer is pulled straight out from the spindle motor’s shaft.
(See “Service Manual for Primary Service,” p. 13.)

Circuits have primarily been configured with the following five boards.

Mounted to this board is the RF amplifier, which amplifies signal output from the optical block. Signals amplified with the RF amplifier

are output to the main board.

Built into the main board are main microprocessor, RAM and nearly all other digital processing circuits. Signals output from the RF board

are subjected to digital signal processing and output to the audio board.

Subjects digital signals output from the main board to D/A conversion, amplifies them with the amp circuit and outputs them. In consid-

eration of sound quality, layout has been given left-right symmetry.

AC voltage input from the power cord is reduced by power transformers, one for digital circuits and one for analog circuits, and input to

the power board. The power board’s series regulator produces and outputs different voltages for analog and digital circuits.

Mounted to this board are the FL tube, FL driver, and display microprocessors. Displays depend on the main board’s microprocessor

output.

OP

RF board

AUDIO board

DISPLAY board

POWER board

MAIN board

Audio
signal

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Operating with a timer available on the market, the player will automatically start playing when a disc is inserted and the power is turned

on. In this case, the following five operations are performed.

When AC voltage is supplied to the power transformer through the power switch, different voltages are output from the power circuit.

When voltage is output, the reset signal is output and the set will start.

If the loading panel is open, it will automatically be closed. Next, the presence of the stabilizer will be confirmed. If the stabilizer is not

there, “NO STABILIZER” will be displayed and set operations will stop.

When the stabilizer can be detected, the spindle motor will be moved to the side where the optical block is.

The type of disc that has been loaded will be detected. If the player judges that the disc cannot be played, it will display “TOC ERROR.”

Table 2-1. “TOC ERROR” Displays

Display

Disc Type

TOC ERROR*

Type that can’t be played (DVD, etc.)

TOC ERROR****

Illegal disc (pirated disc, etc.)

Adjustment values are set in accordance with disc type. Playback will start after some adjustments have been made in keeping with the

disc. When the CD/SACD button setting differs from the disc detected, playback will start in accordance with the disc detected.

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AC plugs for Japan, the US and Canada are tripolar. Thus, a bipolar power plug adapter has been included.
Noise may occur from electric potential differences in ground wires. Although household power outlets usually have a safety ground,

when a tripolar cord is used and each outlet differs slightly in electrical potential, sound quality could deteriorate and ham noise be output. In
this case, attach the conversion plug adapter and use it without connecting the ground wire to anything.

There are two power transformer systems: one for analog circuits and one for digital circuits. Voltage output reduced by the power

transformers (T401 and T451) is output to the power board.

Although the SCD-777ES uses regular power transformers, the SCD-1’s power transformers stress sound quality and thus have been

plugged inside.

The AC board’s analog circuit output has a fuse (F481) that should be checked if no sound is output.

The power board is divided in terms of analog and digital power circuits. The following voltages are output via the rectifying circuit and

series regulator.

DF + 5V for the audio board: Digital filter (IC301)
DAC + 9V for the audio board: Pulse generator (IC302) and current DAC (IC101 and IC201)
DAC - 9V for the audio board: Pulse generator (IC302) and current DAC (IC101 and IC201)
S + 20V for the audio board: Analog amp
A + 20V for the audio board: Analog amp
S - 20V for the audio board: Analog amp
A - 20V for the audio board: Analog amp

D-30V for the FL tube
MOT12V for the motor driver
D5V for the display board: Display microprocessor (IC1001) and FL driver (IC1002)
DRST for the main board: DSD decoder (IC703)
RF5V for the RF board
DIG5V for the main board: Digital IC and +3.3VREG (IC740)
ARP3V for the main board: ARP (IC702) and DRAM (IC707)
DIG3V for the main board: DSD decoder (IC703)

The +12V, +5V and +3V regulator circuits for digital circuits all have fuses, and the -30V regulator circuit has fuse resistance. These
should be checked if circuits do not operate.

The DAC + 9V and DAC - 9V input will be ±7V for the current DAC (IC101 or IC201), in accordance with the series regulator (IC205 or

IC206). In addition, the S+20V, A+20V input will be ±15V for the analog amp, in accordance with the regulator circuit.

The DIG5V input will be 3.3V for the ARP (IC702), in accordance with the series regulator (IC740).

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When the power plug has been connected, the reset signal will be output from the reset signal generator (Pin 6 of IC734) in accordance

with the power board’s DIG5V output. The reset signal will be input to the main board’s main microprocessor (Pin yd of IC701) and other
digital ICs and the display board’s display microprocessor (Pin e; of IC1001).

The reset signals for the ARP (Pin if of IC702) and the DSD decoder (Pin qd of IC703) are input via the logic ICs (IC778 and IC 726).

Using TP708, the main board’s test point, confirm that the reset signal output from the reset signal generator (IC734) is the L-pulse signal
for voltage of 5V (approx. 65µs). Confirm that the signal to the ARP (IC702) is the switch output (Pin 4 of IC778).

The system is controlled with a microprocessor (IC701).When the microprocessor starts up, the set’s operation program is read from a

4Mbyte flash ROM (IC716) and set operations are begun. The buffer for microprocessor operations has SRAM  of 1Mbyte (IC717 and
IC718). Terminal input and output information communicates with the microprocessor via a parallel data bus. Operations other than those of
the display board are controlled with serial data from the expander.

EEPROM (IC735) is provided for backing up data. The various adjustment values set when the player was shipped from the factory, the

operating mode when the power is off, etc., have been saved in EEPROM.

The display is controlled with a display microprocessor (IC1001). When the main microprocessor starts up, “SYS ERROR” will be

displayed if communication with the display microprocessor is abnormal. In this case, confirm the clock, the communication lines and the
like.

When replacing the flash ROM for program version upgrades or the like, remove the black ROM cover and replace the ROM. Remove the
ROM cover by sliding it slightly in the direction of the arrow imprinted on it. When the ROM cover has been removed, you can pull out
the ROM with your finger. After replacing the ROM, put the ROM cover back on by reversing the order in which you removed it.
Make sure never to touch the optical block during this process.

EXPANDER
     IC712

 1MB
SRAM
 IC718

 1MB
SRAM
 IC717

CPU
IC701

EXPANDER
     IC711

DISPLAY MICON
       IC1001

       4MB
FLASH ROM
      IC716

EEPROM
   IC735

D0-D7

D8-D15

EEP_SIO

SINO
SINI