Technics SA-GX550 - SCHEMATIC DIAGRAM INTERPRETATION; Diagram Notes, Cautions, and Handling ICs;LSIs

SA-GX550 |
i SCHEMATIC DIAGRAM (Parts list on pages 52~58.)
(This schematic diagram may be modified at any time with the development of new technology.)
Note 1:
¢ $701 : Voltage adjustment switch in “220—240V”
position.
¢ $946 : Numeric (5) switch.
© $947 : Center level adjust (CENTER LEVEL —)
switch.
¢ $948 : Test signal ON/OFF (TEST) switch.
«$949 : Numeric (4) switch.
¢ $950 : Numeric (6) switch.
¢ $951 : Center level adjust (CENTER LEVEL +)
switch.
¢ $952 : Numeric (7) switch.
° $953 : Rear level adjust (REAR LEVEL —) switch.
¢ $954, 955 : Input select switches.
($954: CD, $955: TUNER]
¢ $956 : Center mode select (CENTER MODE)
switch.
© $957 : Numeric (9) switch.
« $960 : Rear level adjust (REAR LEVEL +) switch.
¢ $961 : Numeric (8) switch.
e $962 : Numeric (0) switch.
¢ $963 : Delay time (DELAY TIME) adjustment.
° $964 : Input select (PHONO) switch.
° S965 : Loudness (LOUDNESS) ON/OFF switch.
© S966 : Memory (MEMORY) switch.
¢ $967 : Muting (MUTING) switch.
¢ S970 : Tape/DCC monitor (TAPE/DCC [MONITOR})
switch.
° $971 : Input select (VCR2) switch.
¢ $972 : Input select (VCR1) switch.
¢ $973 : Speaker select (B) switch.
¢ $974 : FM mode select (FM MODE) switch.
© $975 : Band select (BAND) switch.
¢ $976 : Direct tuning (DIRECT TUNING) switch.
¢ $978 : Power (POWER) switch.
¢ $980 : Dolby pro logic 3 STEREO ON/OFF
(3 STEREO) switch.
¢ $981 : Speaker select (A) switch.
© $982 : Dolby pro logic surround ON/OFF
(SURROUND) switch.
e $983 : Numeric (3) switch.
¢ $984 : Numeric (2) switch.
© $985 : Numeric (1) switch.
° $986 : Tuning mode (TUNING MODE) switch.
© Signal line
coon : FM OSC signal
: AM (MW/LW) OSC signal
: Rec out signal (Lch)
: Rear speaker drive signal (Lch)
: Positive voltage lines
: Negative voltage lines
: FM signal
: AM (MW/LW) signal
% : AF signal (Lch)
=—=——p» <: Center speaker drive signal
¢ Important safety notice
Components identified by A mark have special
characteristics important for safety. Furthermore,
special parts which have purposes of fire-retardant
(resistors), high-quality sound (capacitors), low-noise
(resistors), etc. are used as occation calls. When
replacing any of components, be sure to use only
manufacturer’s specified parts shown in the parts list.
HE
1
¢The supply parts number is described alone in the
replacement parts.
| PartNo. | Original PartNo. | Supply Part No.
RCDHC-278-E RCDHC-278
¢ All voltage values shown in circuitry are DC voltage in
FM signal (Stereo signal) reception mode.
* Figures in ( ) stand for DC-voltage in AM (MW/LW)
signal reception mode.
* Figures in ( J stand for DC-voltage in LW signal
reception mode.
° Caution!
IC and LSI are sensitive to static electricity.
Secondary trouble can be prevented by taking care
during repair.
¢ Cover the parts boxes made of plastics with alminum
foil.
¢ Ground the soldering iron.
¢ Put a conductive mat on the work table.
¢Do not touch the legs of IC or LS! with the fingers
directly.