Kenwood KRC-31Y Schematics

A B C D E

0

5

A

M

SYNTHESIZER UNIT (X14-689X-XX)

CLK

REQ C

R411 100

R408 4.7K

C404 0.01

R415 100K

7
5
6

R413 100K
R414 100K
R412 100K

63

18

17

+B

39

5V
0V

5V
0V

0V

IC8

1

2

3
4

5

6
7

GND

MUTE
DRIVE

PREOUT
MUTE DRIVER

VDD

14
13

12
11
10
9

8

IC1 :

1

IC2 : TDA7407D
IC4 :
IC6 : TDA7479D
IC7 : TDA3682ST
IC8 : HD74HC27FP
IC9 : HA12221F
IC10
IC11
IC12

Q1,301 : DTC124EUA or
Q10,11,20,101,201

Q40 : DTA124EUA or
Q50 : 2SA1036K

Q151 DTA114YUA or:

2

Q223,224 : DTC143TUA or
Q251 : DTC114YUA or
Q501 : 2SD1760

Q551 : 2SB1443
Q552 : DTC114EUA or

D1 :
D2,3 : 1GWJ43 (TPB5)

D4,551 : AM01Z or
D10,11,401,402
D20 : MA4051 (N) -M

3

D40,101,251-253
D102

D153,154,157,159-161,

∗

TDA7386

LB1930M

:

S-80835CNNB

:
: BR24C01AF

UN5212
2SC4081 or:

2SD1819A
UN5112

UN5114
UN5216
UN5214

UN5211
1N5393G-M6 or

S2V20 A

ERA15-01

: MA4068 (N) -M

MA4047-M or:D30
HZS5B1

: 1SS133
: B30-1567-05

403,404,407,409-411

MA4062-L or:
HZS6C1

ACC

RED

BLK

8

A-PART

75

B-PART

7B531

GRN

GRN/BLK

REAR. L

(E30-4792-05)

BATT

P.CONT OUT

ANT.CONT

BLU/WHT

WHT/BLK

FRONT. L

YEL

31

GRY

GRY/BLK

FRONT. R

64

6248

WHT

DC1

2

VIOL

A

VIOL/BLK

REAR. R

CH-IN

B.U.

+B

+B

D404
D407
D401
D402
D403
D409
D410
D411

GND

CON

REQ H

R404 100

R405 4.7K

44

J4

159

2

43812

MUTE

S GND

R403 4.7

R406 4.7K

+

C403 100u10

42

10

13

7611

Lch

Rch

RST

DATA H

DATA C

R402 10

R401 10

R410 100

R407 4.7K

R409 4.7K

C402 1u50+C401 1u50

+

16

SIGNAL LINE
GND LINE

B LINE

A1

CB

YES

X86-3512-70

NO

X86-3512-72

NO

X86-3512-70

NO

X86-3512-70
X86-3512-70

CASSETTE MECHANISM
(D40-1150-05)

YES

UPD780058GC418

NO

UPD780058GC426
UPD780058GC418

NO

UPD780058GC426
UPD780058GC418NONO

PACK

IC1

MODE

R111C308

YES

NO
NOYES

YES

FWD/REV

FWD/REV

R112

NO

YES
YES

R113

YES

YES
YES

NO
NO

4

5

(X14-689X-XX)

MODEL NAME
KRC-394Y (E)

KRC-37Y (E)
KRC-394 (E)
KRC-37 (E)
KRC-36 (E)
KRC-391 (E)
KRC-4904Y (E)
KRC-31Y (E)
KRC-366L (M)
KRC-466R (M)

+B

UNIT

No.

2-70

2-72
2-71
0-22
0-21 YES YES YES

PACK

M1M2

MAIN

HD1

+2V

SUB

M

M

7
6

T-END

5

STBY

4
3
2
1

PLAY

10

HEAD R

9

HEAD COM

8

HEAD L

7

6

GND

F/R

PACK IN

SUB(+)

SUB(-)

MODE+B

MODE

6
5
4
3
2
1

HEAD

Rch

Lch

+2V

CAUTION : For continued safety, replace safety critical components only with
manufacturer's recommended parts (refer to parts list).

Indicates safety critical components. To reduce the risk of electric shock,

leakage-current or resistance measurements shall be carried out (exposed

7

parts are acceptably insulated from the supply circuit) before the appliance is
returned to the customer.

• DC voltages are as measured with a high impedance voltmeter. Values may
vary slightly due to variations between individual instruments or/and units.

M+R
GND

T-END

STBY

GND

R114

NO

NO

NO
YES
YES

R146R118

YESYES

NO NONO

YESNONO

NO

YES YES

HEAD COM

Q301

YES

YES

NO

YES

MODE

MODE+B

SUB(-)

SUB(+)

PACK IN

GND

HEAD L

HEAD R

GND

STBY

T-END

GND

M+B

CN1

F/R

CN2

1

2
3
4
5
6
7

8

9

10

1
2
3
4

5

6

7

R533 470C532 0.01

R534 100K

R536

22K

R535

9
7

19

R556 470
R554 470

20

D551

Q551

1K

R552

470

R531

MOTOR

R551 10K

1/2W

10K

10K

Q552

+2V

+B +B

SUB MOTOR
DRIVER

IC10

6

0V 0V

PGND

7

7.6V

7

+5V

77

470

64
57

9

+B28

C511

1500P

C512

1500P

R513

C513

150

22u6.3

OUT2

8

NC

C533C534

9

7.6V

OUT1

10

NC

0.22 0.22

330K 5.1K

C516

R516

12K

0.01

+

C514

22u6.3

150

R514

3.8V

C509
1u50

+

0V

3.8V

15K

R511

3.8V

15K

R512

3.8V

+

C515

0.01
R517 R519

330K 5.1K

R515

12K

5

SGND

4

5.0V

IN2

IN1

NC

VCC

R520R518

31

NFI (R)

32

R IN (R)

33

RIP

34

F IN (R)

35
36

37

F IN (L)

38

V REF

39

R IN (L)

40

NFI (L)

58

3

5.0V

59

2
1

7.7V

+B

4.3K

R522

C518

0.1u50

3.8V

3.8V

302928272625242322

D IN (R)

M-OUT (R)

EQ OUT (R)

3.8V

EQUALIZER
AMPLIFIER

M-OUT (L)

RQ OUT (L)

D IN (L)

1

2

345

3.8V

3.8V

+

C517 0.1u50

4.3K

R521

+

IC9

3.8V

+B

3.8V

3.8V

RAI (R)

RAI (L)

PB OUT (L)

678

3.8V

PB OUT (R)

MS GV (R)

5V

S/R (MSGV)

0V

9

21

MA OUT

MS DET

5V
1V

MUSIC

MUTE

10

MS GV (S)

MSI

VCC

F/R

MTL

0V

V

V

X-XX)

M

100

270 10 16

23

9

33

X1

4

VDD

TE
IVE

UT
DRIVER

JIHGF

D251

TH1

D252

R258 100

MT

RST

J5

R231R223

C223

D253

R259 22K

34

MUT

B.U

B.U

B.U

GND

GND

GND

T.MUTE

P.CON

ACC

A.5

RR-

RR+

RL-

RL+

FL-

RL-

RR+

R32 22K
C30 0.01

TEL
MUTE

78

D30

RL+

R20

FL-

FL+

FL+

3.3K

R22 47K

1234567 8 910 1112131415161718

R15

56K

R16
100K

Q11Q10

R1

4.7K

D2

SERGE
DET.

R14

D11

R2

82K

9
7

RR-

4.7K

9
7

10K

R30

R31 47K

5.0V

14

+5V

13

5V
0V

12
11
10
9

5V
0V

RST

Q40

22K

MT

5V
0V

22K

MUT

8

+5V

L1

C40 0.01

+B

+B+B

R10

D1

D10

30K

+

C1

3300u16

+5V

+B

C14

1000P

R11
10K

BACK-UP
DET.

D3D4

FR+

FR+

1/2W

C20 0.01

Q20

ACC
DET.

FR-

J2

FR-

R21

47K

D20

DC-IN/SP-OUT

R12 100K

R23 100K

21

22

+B

R256

R255 33K

47K

R263

IC4

POWER
AMPLIFER

C255 1u50

+

C256 100u10

+

Q251

1K

10K

Q251

35

POWER

40

IC SVR
SW

246

47K

GND

4.7V

14.4V

STBY

1

0V

+B

7.3V

8

10121416182022

SVR

VCC

GND

TAB

OUT2-

OUT2+

OUT1-

OUT1+

3

579

7.3V

7.3V

7.3V

7.3V

FR-

RR-

FR+

RR+

4.7K

R254

C252

C254

0.22u50

RR

RR

7.2V

4.7K

R252

0.22u50

IN2

11

7.2V

+B

7.2V

IN4

IN1

13

0V

C251

FR

0V0V0V

0V

GND

GND

7.3V

OUT3+

GND

IN3

1517192123

7.2V

FL+

4.7K

R251

R253

C253

0.22u50

0.22u50

FL

RL

14.4V

4.7K

+B

VCC

OUT3-

FL-

RL

3.3V

MUTE

OUT4+

OUT4-

RL-

RL+

0V

24

GND

CD

25

C258

R260

1u50

750R261

C257 1u50

R257

8.2K

+

R262
180K

50

430

+

D40

+B

+5V
+5V
+8V

77

1V

5V

2.5V

80

5V
0V

BU-DET

22

R107 47K
R109 47K

∗

R111 47K

∗

R113 47K

AV CONT

5V
0V

5V
0V

5V
0V

5V
0V

2.5V

1.6V

79

NOISE

5V
0V

5V
0V

5V
0V

5V
0V

IC2 TYPE 0

232425

0V

+5V

C106

22K

78

4700P

R141

4.7K

R142

78

77

76757473727170

PHONE

T-MODE

S-METER

5V
0V

R140
160K

AV REF 0

4V
0V

5.0V

VDD 0

+5V

XT1

5V
0V

C105

15P

IC

XT2

∗

IC1

SYSTE
u-COM

C10

0V

5V
0V

5V
0V

IC2 TYPE 1

TYPE 0

TYPE 1

26

0V

0V

0V

5V
0V

∗

R112 47K

∗

R114 47K

5V
0V

TYPE REF

MOTOR

282930

27

5.0V

5V
0V

5V
0V

PLL-CESDAFS

R116 4.7K

R115 2.2K

29

30

5
0

LO/DX

31

32

R117 4.7K

R118 2.2K

∗

32

MOTOR DRIVER
AVR

R537

C531

22

+

10u10

+8V

Q501

+8V

L201

FL

4.1V

262725

OUT FL

L

3

4.1V

RL

FR

4.1V

4.1V

24

OUT RL

OUT FR

CD RRPH-

5

4

4.1V

4.1V

5

4.7uH

RR

4.1V

8.3V

232122

OUT RR

CD GND

678

4.1V

4.1V

6

C201

47u10

+

C202

0.01

0V

VDD

E-VOLUME

CD L

AFS

9

4.9V

7

9

38

37

192018

SCL

SDA

GND

MPXAMLEVEL

11

10

C207 0.47

C206 0.015

R201 2.7K

R202 4.7K

11

10

5V
0V

4.1V

C210 0.033

C508

R504

0.01

24K

22

21

4.7

R502

C507

0.47u50
+

0.22u50

180K

C501

C505

+8V

47u10

R501

+

56

+

0.01

C502

IC2

C205 1
C204 1

28

AC OUT L

VREF

1

C203

AC OUT R

GREF

2

4.2V

+

2.2u50

MS GV (R)

MA OUT

MS DET

5V
1V

MUSIC

S/R (MSGV)

MUTE

10

MS GV (S)

MSI

VCC

F/R

MTL

R503

1.6K

4.0V

20

C506

19

0.01

18

4.0V

17

8.0V

16
15

54

14

55

0V

13

0V

12
11

5V
0V

Q201

S MUTE

12

0V

C209 0.1

C211 150P

3.6V
0V

R203

4.7K

R204

+5V

1K

0V

17

QUAL

MP IN

13

0V

13

4.7K

R205

16

15

MUX OUT L

MUX OUT R

MP OUT

14

3.8V

C208 0.1

∗

NOISE
DETECTION

5.0V

2.5V

∗

R146

2.2K

R104

5V
0V

5.0V

0V

100K

DSI

Q101

1
2

3

4

5
6
7

8
9

10

11

12
13

14
15
16
17
18
19
20

4.3V
0V

0V

DSI
PAN EL

AVSS

L-RST
L-CE

AVREF1

PLL-DATA
PLL-CLK

L-DATA L

L-DATA S
L-CLK

R- DATA
R-QUAL
CH-DATA C
CH-DATA H
CH-CLK
M-STBY
T-END

ACC-DET

21

22

21

D102

R143

+5V

B

240

5V
0V

2

5V
0V

5
6

+5V

R102

2.2K

8

R103

2.2K

10

11

R105 2.2K

12

R106 2.2K

13
14

15
16
17
18

19
20

28