SCD-1, SCD-777ES - Sony Audio Service Manual (repair manual). Page 7

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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).