Sony PMC-20 Service manual

digital
voltmeter

100 kΩ

TP (VT)

)

PMC-20

SERVICE MANUAL

Ver 1.0 2000. 02

Model PMC-20 is almost same as PMC-107 US model.
This manual contains only the points which differ from PMC-107 US model.
For the information not contained in this manual, please refer to PMC-107 service manual (9-924-914-S).
( ) : Refer to page of this manual (PMC-20)
(( )): Refer to page of PMC-107

1. ELECTRICAL ADJUSTMENTS ((Page 14))

TUNER SECTION 0 dB = 1 µV

• FM Section

Setting:

BAND switch: FM

FM RF signal
generator

TP (FM ANT)

0.01 µF
set

22.5 kHz frequency
deviation by 400 Hz signal
output level : as low as possible

• Connecting Level Meter (FM and AM)

32 Ω

set

phones jack

• Connecting Digital Voltmeter (FM and AM)

US Model

level meter
(range: 0.5–5 V ac

• AM Section

Setting:

BAND switch: AM

AM RF signal
generator

30% amplitude
modulation by
400 Hz signal

Put the lead-wire
antenna close to
the supplied MW/LW
loop antenna.

• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.

PERSONAL COMPONENT SYSTEM

– 1 –

FM FREQUENCY COVERAGE

CHECK

Frequency Display 87.6 MHz 108 MHz
Reading on Digital voltmeter 1.55 ± 0.2 V 4.0 ± 0.2V
Adjustment Part <confirmation> <confirmation>

FM TRACKING CHECK

Adjust for a maximum reading on level meter.

<confirmation> <confirmation>

87.6 MHz 108 MHz

AM FREQUENCY COVERAGE

ADJUSTMENT

Frequency Display 530 kHz 1,710 kHz
Reading on Digital voltmeter 0.75 ± 0.05 V 5.4 ± 0.2V
Adjustment Part L2 CT2

AM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L9 CT4

620 kHz 1,400 kHz

Adjustment Location: main board

– MAIM BOARD (COMPONENT SIDE) –

TP (VT)

TU1

R31

AM

TRACKING

ADJUSTMENT

AM

FREQUENCY

COVERAGE

ADJUSTMENT

TP

(FM ANT)

L9

CT4

L2

CT2

– 2 –

2. DIAGRAMS

2-1. BLOCK DIAGRAM — MAIN SECTION — ((Page 25))

PMC-20

ANTENNA

AM

ANTENNA

FM

04

CNP1
LOOP

FM

LEAD

HRP301

RECORD/PLAYBACK

L-CH

R-CH

CAPSTAN /REEL

S301

(MD POWER)

S302

(MD PLAY)

D302

PON+B

AM

HEAD

LPF
Q11

REG
Q12

M301

MOTOR

M

R-CH

VREF

CT4, L9

AM

TRACKING

CT4

3
4

8

((Page 24))

CD SECTION

T301

REC

BIAS

VREF

Q301, 316

+8V

FREQUENCY

COVERAGE

D5

L9

(AM ANT)

OSCOUT
VT

RFIN

RFPUT

VDD

TUNER PACK

TU1

SW301-2

PB REC

62

T-PLAY

CT2, L2

AM

CT2

CD L-CH

1

VREF

SW301-1

PB REC

BIAS
OSC

55

23–20

+8V

1
5

Q303

REC

COM0

LCD801

+5V

REC

REC/PB

CONTROL

Q302, 315

COM3

19–1, 80–78 30•31 35–38

L2

AMP

Q1

PB

SEG0

SEG21

70 69 68 57

4 5 6 7

PD1

21

AM RF

24 3 7

FM
RF

1

CDIN1

22

PBIN1

5

REC1

4

P/R

21

6

VREFVREF

R-CE

R-CLK

R-DATA

R-COUNT

CE

CK

DA

CD

AM IN

FM IN

17 16 1 2 8

FM

MIX

FM

OSC

OSC

2123

AM

OSC

AM

MIX

PRE-AMP

IC301

ALC AMP

RAIN1

24

TEX

TX

X802

32.768KHz

PLL
IC2

XOUT

X1

75KHz

FM/AM FRONT-END, IF DET,

FM STEREO DEMODULATOR

OUT1

20 31 24 2

TU 5V

CONTROL

CLOCK

SHIFT

Q804

XIN

IC1
CFT1

Q20

SEL

17

TAPE

15

52

TAPE

72 74 76 32 58 6167

SYSTEM CONTROL/LCD DRIVE

EXTAL

XTAL

X801

4.19MHz

CLOCK

SHIFT

Q803

MO/ST

9 14

Q10

14 181922

IF

MO/ST

BUFFER

6

CF2CF1

5V REG

Q2

IC801 (2/2)

SHIFT-CLK

IF IN

AM

DET

FM

DET

AUDIO 8V

RESET

IC804

COM 5V

FM

15 10

BAND

QUAD

VOLUME/SOUND CONTROL

IC302

IN2

SURROUND TONE VOL

CONTROL

PORT2

PORT1CKDATA

13 12 20 19 18

RST

R-ST

R-MUTE

Q15

Q8

ST-IND

AF

BUFFER

17 16

OUT2

VC

23

Q304

BC

LATCH

21

MUTE
CONTROL
Q305, 317

49 48 50 47

V-CE

V-CLK

V-DATA

KEY1

KEY4

WP

Q805

D806, 807

SW801

|

SW819

H. FREQ.

CUT

Q7

IF CUT

CF4CF3

AUDIO 8V

FM

MPX

13

VCO

H. FREQ.

POWER AMP

POWER AMP

CONTROL
Q313, 314

A-MUTE

MUTE

189

IF CUT

Q9

IC303

STBY

5

60

RECEIVER

R
L

PA-CON

28

SIRCS

IC803

12
11

RMC

R-CH

R-CH

12

RADIO

53

CD

54

REG-CON

REG-CHK

42

51

COM 5V

VDD 5V

+5V

TU 5V

CD 5V

+8V

D802

D805

D804

J302

PHONES

SP301

SPEAKER

(L-CH)

TUNER 5V

SWITCH

Q306

CD 5V

SWITCH

Q307

LED/LAMP

B+ SWITCH

DRIVE

Q806

Q801, 802

D801

OPERATION

VCC

5V REG

Q308

8V REG

Q309, 310

POWER ON

SWITCH

Q311, 312

+5V REG

IC802

RECT

D901–904

D905

T901

POWER

TRANSFORMER

AC IN

Signal path

: FM

R-CH

: AM
: PLAY

Q13

: REC
: CD

R-ch : same as L-ch.

– 4 –– 3 –

PMC-20

2-2. PRINTED WIRING BOARD — MAIN BOARD — ((Page 32))

Comon Note on Schematic Diagram:

• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.

• All resistors are in Ω and 1/
specified.

f

•

: internal component.

4

W or less unless otherwise

• 2 : nonflammable resistor.

• 5 : fusible resistor.

• C : panel designation.

Note: The components identified by mark 0 or dotted line

with mark 0 are critical for safety.
Replace only with part number specified.

• U : B+ Line.

• Voltage is dc with respect to ground under no-signal
(detuned) condition.
no mark : FM
( ) : AM / TAPE PB
< > : TAPE REC
[ ] : CD

• Voltages are taken with a VOM (Input impedance 10 MΩ).
Voltage variations may be noted due to normal produc­tion tolerances.

• Signal path.

F : FM
f : AM
E : PB
a : REC
J : CD

Comon Note on Printed Wiring Boards:

• X : parts extracted from the component side.

f

•

: internal component.

• b : Pattern from the side which enables seeing.

• Semiconductor Location

Ref. No. Location
D1 B-4

D2 B-3
D4 C-7
D5 C-4
D6 B-4
D7 B-3
D8 E-5
D301 F-3
D302 E-4
D303 F-7
D304 I-5
D305 H-10
D306 I-4
D307 J-3
D308 H-9

Ref. No. Location
Q9 E-5

Q10 D-4
Q11 C-9
Q12 C-10
Q13 D-6
Q14 D-6
Q15 C-6
Q20 B-6
Q301 J-8
Q302 I-9
Q303 I-9
Q304 E-9
Q305 E-9
Q306 G-6
Q307 F-7

Q308 I-5
IC1 C-5
IC2 D-8
IC301 H-7
IC302 F-8
IC303 G-5

Q309 I-4

Q310 J-5

Q311 I-5

Q312 I-5

Q313 E-4

Q314 F-4
Q1 B-5
Q2 C-8
Q7 D-5

Q315 H-9

Q316 I-9

Q317 E-8
Q8 D-5

A

B

C

D

E

F

G

H

J

1

SP301

SPEAKER

L-CCH

SP302

SPEAKER

R-CCH

I

234567891011

MAIN BOARD

R9

C75

C73

L6

CT4

C7

R10

R54

L2

C11

C76

JW92

C21

CF4
C19

R15

C20

R109

R332

C118

C218

C313

C119

R217

R110

C116

C320

C117

C115

C312

R341

C112

C114

R345

C360

Q309

JW43

L9

C16
C18

R116

C310

C41

R43
JW60

L302

JW51

R340

S

R36

C4

JW108

C213

C216

Q1 R5

R1

C6

JW65

C13

JW63

Q7

Q8

IC303

Q308

C8

R209

C342

JW77

C17

JW83
JW81

R210

R333

L12

IC1

JW26

JW4

JW52

R215

JW6

JW3

C214

C318

C61

124

1213

C22
C23

C212

R216

R334

Q310

C5
C31

R40

R38

L7
C14
L1
C64

C2

Q9

D8

JW101

JW59
JW58
JW57

JW45

R342

C215

C217

(CHASSIS)

JW7

Q311

D304

R39

R13

C15

C26

CF2

C25

CF3

C333

C319

Q312

Q20

C24

JW50

JW35

JW104

JW66

C42

C43

R46

R14

R337

CNP305

1

3

JW10
JW11

JW9

JW17

R44

R41

R35

R108

C65

BLK
BLK
WHT

R335
C317

CF1

C59

C58

CFT1

L13

R42

JW44

JW105

R47 R48

R45

JW73

C44

Q14

C45

JW30
JW34

JW62

JW8

JW47

JW89

JW96

JW39

JW42

JW2

JW90

Q15

JW78

JW41

JW79

JW74

R53

C9

Q13

JW28

JW103

C309

R211

Q306

JW38

C341

R302

JW88

C203

JW19

POWER
BOARD
CNP901

R16

C211

R208

C311

C204

R203

D4

R25

JW67

JW53

JW102

JW87

R37

JW12

C338

C336

C339

D303

C308

BLK

BLK

CNP304

17

BLK

R308

JW85

JW1

C205

R212

JW36

13 24

R204

C202

R202

R201

C201

C340

CNP301 CNP302

1414

BLU

HRP301

RECORD/PLAYBACK

HEAD

JW98

R107

Q307

R213

C347

RED

Q2

R33

JW97

C107

R207

C207

BLK

JW100

JW61

R205

R105

YEL

WHT

C46

L5

C34

C56

C29

R34

C306

C109

C108

32 17
1

C208

R309

WHT

JW27

JW64

C206

R214

IC301

C102

R101

BLK

JW76

C3

L3

C33

C30

R28

JW93

C111

C110

IC302

JW106

C209

JW31

JW82

WHT

REC SW
CNP801

C1

R22
JW109

R324

JW107

C210

JW5

R114

C106

112

R104

C101

C103

BLK

BLK

BOARD

C12

C307

JW33

C326

Q317

16

R102

JW54

R329

C316

C315

R112

R113

C302

JW18

Q301

IC2

C327

R111

C105

R301

C334

JW80

R12

C35

R336

C330

JW40

R103

1458

C37

JW49

JW94
JW32

TU1

JW99

JW95

R27

C39

3217

116

C51

Q305

R323
Q304

R338

C331

JW25
JW21

C303

Q315

Q302

C104

C345

JW22

C332

C335

Q316

(MD POWER)

(MD PLAY)

C36

R29

C52

C323

R325

C325

S301

S302

S

R339

C348
JW48

JW24

T301

JW20

C53

C27

R17

R322

R321

JW29

R303

R304

C301

R3

C38
R30

Q11

C28

R18

R19

C321

JW70

JW15
JW13

CNP303

2

22

23

JW37

Q303

C337

R26

X1

R20

1

D308

C304

R306

L8

C40

R32

S

JW84

R305

R343

Q12

C74

JW55

JW75

JW56

JW72

R327

JW46
JW69

C328

JW16

JW71

JW86

D305

R307

C305

CNP306

BRN

1

BRN
BLU

BLU
RED
BLK

6

1-670-854-

BLU
BLU
BRN
BRN

R31

JW68

R326

C324

JW23

((Page 40))

C346

11

(11)

(CAPSTAN/REEL)

RED BLK

3

CONTROL

BOARD

CNP801

M301

CD BOARD

((Page 28))

L

L

R

R

CNP704

H.P BOARD

CNP704

((Page 33))

AM

LOOP

ANTENNA

CNP1

AM

1

J301

RL

04

FM

LEAD

ANTENNA

CNP1

WHT

BLK
BLK
BLK
BLK

D2

D5

D302

C343

C329

R330

D301

R

L

CNP307

FM

D7

5

1

D307

C10

Q313

Q314

C219

C314

D6

CT2

C113

R117

D306

D1

C72

Q10

C344

R115

((Page 34)) ((Page 34))

– 5 – – 6 –