Technics RS-TR474

29
30
31
32
33
34
Ls
amc
(5)
Q709
2SC33IIAIRTA
LED ORIVE
Q7TO7T
» DTCILAESTP
oy PEO ORIVE
1c 702
XLU93LC46AFE
EEPROM
0701
LN2BRPX
(STANDBY)
For (E,EB, EG)
areas.
mMmonwp
(-8V)P;
(-5.6V) Py
(+5.6ViP;
ic7ol .
E.G) rpt2 M38123M4101F
STD RPS2 MICRO COMPUTER
6) Voo (SYSTEM CONT/
Ea)
FL ORIVE)
wes ~4.8V
O.tys. 2V/DIV.
z7ol
RCOHC - 278N
(SENSOR)
Ge-ranNnMooDgD
F=4MHz
R760 22K
R774 22K
(REC LEVEL)
R720 VR702
1OOK(B)
15K
2SC33IIAIRTA
REC BIAS CONT.
WRT4S MR746 KRTST RR74E R749 MR75SO RTS MR752 #R753 RR754 RRTS5
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START)
pss
RESET)
—_— —_—
}—<o
s720
$723
(SYNCHRO
(4 OPEN/CLOSE)
$722
(REVERSE MODE)
(SPEED)
$724
pi at
fo
$7l2
(COUNTER2
Na dD CK |
CIRCUIT
cN704 —
WRITE
CONNECTOR
L_@y [tror ic702)
ne
METER Loh
| ey METER Rch
(3) +B (E.VR)
me E.VR Leh
ea {is} 0.GND
ol +812)
(21) +B (3)
(29) + B14)
(3) -VP
G4] M.GND
G5) HP Rech
GHP Loh
Ga HP GND
3
troRJmain
(14) OMT CIR
(CN3B)
UIT
JKTIO
HEADPHONES
| RS-TR474
i SCHEMATIC DIAGRAM (Parts list on pages 57~60.)
(This schematic diagram may be modified at any time with the development of
new technology.)
Note 1:
¢$701 : Dolby noise-reduction switch (DOLBY NR; Bl, [€)).
¢S702 : DECK 2 Stop switch (MM).
¢S703 : DECK 2 Forward-side playback switch (P).
¢S704 : DECK 2 Reverse-side playback switch (<d).
¢S705 : DECK 2 Fast-forward search switch (> TPS).
¢S706 : DECK 2 Rewind search switch (<<q TPS).
¢S707 : DECK 2 Open/close switch (4 OPEN/CLOSE).
eS708 : DECK 2 Record switch (@ REC).
¢S709 : DECK 2 Pause switch (§ PAUSE).
¢$710 : DECK 2 Automatic-record-muting switch (Q AUTO REC MUTE).
¢S712 : DECK 2 Counter reset switch (COUNTER 2 RESET).
¢©S714 : Power “STANDBY « /ON” switch (POWER, STANDBY © /ON).
¢S715 : DECK 1 Stop switch (MB).
¢S716 : DECK 1 Fowarde-side playback switch (p>).
°S717 : DECK 1 Reverse-side playback switch (<q).
°S718 : DECK 1 Fast-forward search switch (b> TPS).
¢S719 : DECK 1 Rewind search switch (<< TPS).
¢S720 : DECK 1 Open/close switch (4 OPEN/CLOSE).
¢S721 : Auto tape calibration switch (ATC).
¢$722 : Reverse-mode select switch (REVERSE MODE).
¢ $723 : Synchro-start switch (SYNCHRO START).
¢S724 : Tape-to-tape recording-speed switch (SPEED; X1, X2).
eS725 : DECK 1 Counter reset switch (COUNTER 1 RESET)
¢S801 : DECK 1 Cassette holder open detection switch in “off” position.
°S802 : DECK 1 Cassette holder close detection switch in “off” position.
¢S$803 : DECK 2 Cassette holder open detection switch in “off” position.
¢S804 : DECK 2 Cassette holder close detection switch in “off” position.
eS971 : DECK 1 Mode switch in “off” position.
¢ S971A : DECK 2 Mode switch in “off” position.
¢S972 : DECK 1 Half switch in “off” position.
¢ $972A : DECK 2 Half switch in “off” position.
eS973 : DECK 1 ATS (CrO,) switch in “off” position.
¢ S973A : DECK 2 ATS (CrO,) switch in “off” position.
¢S974A : DECK 2 Reverce rec. inhibit switch in “off” position.
¢S975A : DECK 2 Forward rec. Inhibit switch In “off” position.
¢ S976A : DECK 2 ATS (Metal) switch in “off” position.
¢ Resistance are in ohms (Q), 1/4 watt unless specified otherwise.
1K=1,000 (), 1M=1,000k (Q)
¢ Capacity are in micro-farads (uF) unless specified otherwise.
¢
All
voltage
values
shown
in
circuitry
are
under
no
signal
condition
and
playback
mode
with
volume
control
at
minimum
position
otherwise
specified.
(
)
scsueaces
Voltage
values
at
record
mode.
For
measurement
us
EVM.
¢ Important safety notice
Components identified by A\ mark have special characteristics important for safety.
When replacing any of these components, use only manufacturer's specified parts.
(+B >_—<) indicates +B (bias).
° (mim mK —B>w mmm) indicates —B (bias).
e( sumone ) indicates the flow of the playback signal.
o( —> ) indicates the flow of the record signal.
¢ The supply part number is described alone in the replacement parts list,
> marks indicate printed resistor.
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 aluminum foil.
¢ Ground the soldering iron.
¢ Put a conductive mat on the work table.
* Do not touch the legs of IC or LSI with the fingers directly.