Sony STR-DB925 Service Manual

MICROFILM

STR-DB925

SERVICE MANUAL

Photo: BLACK

AEP Model

UK Model

Australian Model

SPECIFICATIONS

— Continued on next page —

FM STEREO/FM-AM RECEIVER

– 1 –

Notes on chip component replacement

• Never reuse a disconnected chip component.

• Notice that the minus side of a tantalum capacitor may be
damaged by heat.

SAFETY-RELATED COMPONENT WARNING !!

COMPONENTS IDENTIFIED BY MARK ! OR DO TTED LINE
WITH MARK ! ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.

– 2 –

TABLE OF CONTENTS

1. SERVICING NOTE ..........................................................3

2. GENERAL ..........................................................................5

3. DIAGRAMS

3-1. Circuit Boards Location ........................................................ 6

3-2. Block Diagrams

• DSP Section ........................................................................ 7

• Input Section.......................................................................9

• Power Section ................................................................... 11

• Dolby Section ...................................................................13

3-3. Schematic Diagram – Input Section – ................................ 17

3-4. Printed Wiring Board – Input Section – .............................. 19

3-5. Schematic Diagram – Power AMP Section – ..................... 21

3-6. Printed Wiring Board – Power AMP Section –...................23

3-7. Schematic Diagram – Trans Section – ............................... 25

3-8. Printed Wiring Board – Trans Section – ............................. 27

3-9. Schematic Diagram – Rear AMP Section – ........................ 29

3-10. Printed Wiring Board – Rear AMP Section – .................. 31

3-11. Schematic Diagram – Display Section – ......................... 33

SECTION 1

SERVICING NOTE

3-12. Printed Wiring Board – Display Section – .......................35

3-13. Schematic Diagram – Panel Section – ............................. 37

3-14. Printed Wiring Board – Panel Section –........................... 39

3-15. Schematic Diagram – Back Panel Section – .................... 41

3-16. Printed Wiring Board – Back Panel Section –..................43

3-17. Schematic Diagram – Volume Section – ..........................45

3-18. Printed Wiring Board – Volume Section – ....................... 47

3-19. Schematic Diagram – D In/Out Section – ........................ 49

3-20. Printed Wiring Board – D In/Out Section – ..................... 50

3-21. Schematic Diagram – Digital (1/2) Section – .................. 51

3-22. Schematic Diagram – Digital (2/2) Section – .................. 53

3-23. Printed Wiring Board – Digital Section – ........................ 55

3-24. IC Block Diagrams ........................................................... 57

3-25. IC Pin Functions ............................................................... 60

4. EXPLODED VIEWS

4-1. Case and Back Panel Section.............................................. 68

4-2. Front Panel Section ............................................................. 69

4-3. Chassis Section ................................................................... 70

5. ELECTRICAL PARTS LIST ........................................ 71

FACTORY SET

Mode which sets the preset settings of the unit to that at shipment.

Procedure:

With the power off, press the 1/u button while pressing the SET UP and SOUND FIELD ON/OFF buttons to turn ON the power.
“FACTORY SET” will be displayed and FACTORY PRESET will be executed.
As the “DEMO MODE” will automatically be set about 1 minute later, press the 1/u button to turn OFF the power.

INITIALIZATION

This mode erases all the preset settings of the unit.
Use this mode when returning the unit to custimer.

Procedure:

With the power off, press the 1/u button while pressing the DISPLAY and SOUND FIELD ON/OFF buttons to turn ON the power.
As the “DEMO MODE” will automatically be set about 1 minute later, press the 1/u button to turn OFF the power.

FLUORESCENT INDICATOR TUBE AND LED LIGHTING CHECK

Mode which lights up the whole fluorescent indicator tube or partially.

Procedure:

With the power of f, press the 1/u button while pressing the SET UP and SOUND FIELD MODE buttons to tur n ON the power . The whole
fluorescent display tube will light up.
As the “DEMO MODE” will automatically be set about 1 minute later, press the 1/u button to turn OFF the power.

DEMO MODE (NOT USED IN SERVICE)

Mode for demonstration

Procedure:

With the power off, press the 1/u button while pressing the CURSOR button to turn ON the power.
To end, press the 1/u button to turn OFF the power.

PRECAUTIONS ON REMOVING THE FRONT PANEL

When the front panel is removed, the front panel board and VOLUME board cannot be connected, thus causing the following problems.

• The MASTER VOLUME LED does not light up

• The MASTER VOLUME cannot be turned UP/DOWN using the remote controller.

– 3 –

DSP SELF DIAGNOSIS FUNCTION

This unit is equipped with a DSP self-diagnosis function.
After completing self-diagnosis, the “DSP TEST MODE” can be set, where signals input from the external equipment will be
assigned to the designated channels as shown in the table below.

Table-1 Assignment of Signals in DSP TEST MODE

Input Signal

FRONT L-ch
FRONT R-ch

Procedure:

1. Connect external equipment such as CD and DVD players using the DIGITAL cable (optical or coaxial).

2. Rotate the FUNCTION knob, and switch to the FUNCTION connecting the external equipment.

3. Press the INPUT MODE button, and select the type of DIGITAL signal connected at 1.
(“AUTO INPUT” is recommended for convenience.)

4. Press the 1/u button to turn OFF the power.

5. Press the 1/u button while pressing the SET UP and SOUND FIELD GENRE buttons to turn ON the power.

6. Perform DSP check in the following sequence to display the results. If no problems, “DSP NO ERROR” will be displayed on the
fluorescent indicator tube, and the reference signals of the 1 KHz internal oscillation will be output to FRONT, REAR, CENTER, and
WOOFER.

Sequence :

1 DSP1 BOOT ERROR CHECK (DSP1:IC1301)

2 DSP1 REPLAY ERROR CHECK

3 DSP2 RAM ERROR CHECK (DSP2:IC1402 RAM:IC1402)

4 DSP2 REPLAY ERROR CHECK

Refer to Table 2 if errors occur and perform the repairs.

FRONT L-ch + CENTER + REAR L-ch
FRONT R-ch + WOOFER + REAR R-ch

Output T o

µ

µ

µ

Table-2 Display of Errors and Main Causes

Error Message

DSP1 BOOT ERROR
DSP1 REPLY ERROR
DSP2 RAM ERROR
DSP2 REPLY ERROR

7. Each time the < , ∧ , ∨ , or > button is pressed, the display changes between “DSP TEST MODE” and “DSP NO ERROR”.
When “DSP TEST MODE” is displayed, the signals input from the exter nal equipment connected at 1. will be assigned to the outputs as
shown in Table 1.
When “DSP NO ERROR” is displayed, the ref erence signal of the internal oscillation will be output to the FRONT , REAR, CENTER, and
WOOFER channels.
(Each time the < , ∧ , ∨ , or > button is pressed, self-diagnosis will be executed from 3 of step 6.

8. To end, press the 1/u button and turn OFF the power.

Note:

Do not touch other buttons except < , ∧ , ∨ , or > during this mode with a specific purpose.
Messages are displayed in the same way as in normal operations.
Operations itself will not be normal here, therefore if other buttons or knobs are touched by accident and the message is changed, press
the 1/u button to turn OFF the power and exit the mode.

Faulty connection of IC1301, fault around the power supply of IC1301
Fault of peripheral circuit of Pin @º of IC1301
Faulty connection with RAM (IC1402)
Faulty communication with microprocessor, fault of peripheral circuit of Pin !£ of IC1401,
fault around power supply and clock of IC1401

Possible Cause and Countermeasure

– 4 –

Front Panel Descriptions

SECTION 2

GENERAL

1

234

65

47

46

45

42 164344

41

LOCATION OF PARTS AND CONTROLS

1 1/u (power) switch
2 VIDEO 1 indicator
3 VIDEO 2 indicator
4 VIDEO 3 indicator
5 DVD indicator
6 TV/LD indicator
7 MULTI CHANNEL DECODING indicator
8 TAPE indicator
9 MD/DAT indicator
10 CD indicator
11 TUNER indicator
12 PHONO indicator
13 MASTER VOLUME knob and indicator
14 MUTING indicator
15 MUTING button
16 FUNCTION knob
17 MODE switch
18 SOUND FIELD indicator
19 EQ indicator
20 BASS BOOST button
21 BALANCE knob
22 SOUND FIELD ON/OFF button
23 SOUND FIELD MODE button
24 SOUND FIELD GENRE button

78

33343536 2324

3237383940

10 11 13

129

28

2629

30

27

25 INPUT MODE button
26 5.1 INPUT button
27 EQ ON/OFF button
28 SET UP button
29 SURROUND indicator
30 EQUALIZER indicator
31 INDEX indicator
32 <, ∧, ∨, > buttons
33 SET UP button
34 RDS EON button
35 RDS PTY button
36 TUNING + button
37 TUNING – button
38 VIDEO 3INPUT jacks
39 FM MODE button
40 MEMORY button
41 DISPLAY button
42 PRESET TUNING + button
43 PRESET TUNING – button
44 FM/AM button
45 SHIFT button
46 PHONES jack
47 SPEAKERS knob

14

15

18

22

21

19

17

20

2531

– 5 –

3-1. CIRCUIT BOARDS LOCATION

SECTION 3

DIAGRAMS

H.P board

F-VIDEO board

SP-S board

BALANCE board

VIDEO board

S-VIDEO board

TUNER board

D. IN/OUT board

5.1 IN board

AUDIO board

VOLUME board

DISPLAY board

SP SW board

AMP board

LED board

AC board

SW board

REG board

REAR AMP board

JOINT board

DIGITAL board

INPUT board

ROTARY board

– 6 –

3-2. BLOCK DIAGRAMS

– DSP SECTION –

STR-DB925

E

DOLBY

SECTION

(Page 14)

AUDATA2
AUDATA1
AUDATA0

BCK

LRCK
SCLK

SCCLK

SRDT

ERROR

2

SOA

3

SOB

4

SOC

SIC

119

SIB

118

SIA

117

BCKO

113

LRCKO

115

CLK1

99

ED16 ED31 EA0 EA15

53-60 62-69

...

7-10 13-16 29-32 35-38

D0 D15 A0 A15

DIGITAL SIGNAL

PROCESSOR

IC1401

..

.

76-80 83-90 92-94

...

5-1 44-42 27-24 21-18

STATIC RAM

IC1402

XWE XCE

74 70

17

41

CEWE

SOD

HD0

HD7

HAO

XRST

XHDCS

HRDY

XHDWR

XHDRD

5

16

I

20

23

I

25

15
26
14

13

9

10

10
12

8

BUFFER

Q1207

BUFFER

Q1206

INVERTER

IC1202

78

SOD

37

HD0

25

I

32

HD7

HAO

35

XRST

36

XHDCS

24

HRDY

23

3
1
5

21
22
16

75
40

XHDWR
XHDRD
SCLK

SRDT
ERROR

SYSTEM CONTROL

IC1201(2/2)

SCLK
XLAT

SWDT

RESET
DIG-IN2
DIG-IN1
DIG-IN0

CDTO

CDTI

CCLK

EVSTB
EVDATA

EVCLK

ACMUTE

DISPDATA

DISPCLK

DISPMR

SLVDATA/REQ

RESET

77
76

2

C

109

B

110

A

111

7

PD

6
5
4
3

CS

48
49
50

84

52
55
51
53
90

SDTI1
SDTI2

SDTI3

SCLK

XLAT

SWDT

RESET
C

B
A

PD
CDTO
CDTI
CCLK
CS

VOL CE

VOL DATA
VOL CLK

AMUTE

UDATA
UCLOCK
UMREQ
USREQ
URESET

D

DOLBY

SECTION

(Page 13)

BUFFER

Q1203

XTALERR

ANA/DIGI

SCDIN

CS

RESET

SCDOUT

INTREQ

09

F MUTE

CONTROL

Q1201,1202

SWITCH

Q1208

BUFFER

Q1204,1205

X1201

4MHz

FUNMUTE

85

XTALERR

13

ANALOG/DIGI

14

SCDIN

15

CS

17

RESET

20

SCDIO/OUT

18

INTREQ

19

XI

93

XO

92

RY-FRONT/A
RY-FRONT/B

RY-CENTER

WOOFER-RY

RY-POWER

RY-REAR

RY-HP

PROTEC

STOP

SINO

SOTO

MDO
MD2

101
102
103
104
105
106
107

79
64

9
10
89
87

• Signal path
: FM

SP/A RY
SP/B RY
C RY
SUR RY

W RY
HP RY
P RY

PROTECT
STOP

SINO
SOTO
MDO
MD2

F

POWER

SECTION

(Page 11)

: CD
: DIGITAL IN

FMUTE

G

INPUT

SECTION

(Page 10)

– 7 –

– 8 –

STR-DB925

– INPUT SECTION –

TUNER UNIT IS SUPPLIED AS THE ASSEMBLED BLOCK

FM

75Ω

AM

J301

TV/LD

DVD

VIDEO2

VIDEO1

PHONO IN

MD/DAT

REC OUT

TAPE

REC OUT

AUDIO IN

AUDIO IN

AUDIO OUT

AUDIO IN

AUDIO IN

AUDIO OUT

CD IN

IN

L

L

J302

L

L

J303

LIN

L

J305

L

L

L

L

L

L

J304

AM

FM

FNIF

TM301

TUNER UNIT

MUTING

STEREO

DO

STEREO

DO

MUTING

TUNED

TUNED

DATA

S DATA

L OUT

R OUT

RDS

CLK

CE

S CLK

S LAT

EQ AMP

IC303

31

R CHR CH

AUDIO SELECT

3

2

1

7

5

6

10

9

CONTROL

SDATA

AUDIO SELECT

1

2

6

7

10

9

CONTROL

IC301

1514

SCLK

IC303

DOLBY

(Page 14)

CENTER

WOOFER

SECTION

LS

27

26

24

23

4

5

1

2

SELECTOR

IC303

CONTROL

14

15

SCLK

SDATA

RELAY
DRIVE

Q301

LPF

VOL

MOTOR

IC103

3

IC405

IC406

8
7

1

LPF

13

75

13

UP

DOWN

RY301

25

22

6

3

13

SLAT

MUTE
Q302

MUTE
Q303

MUTE
Q304

MUTE
Q354

3
2

LPF

IC407(1/2)

LPF

IC407(2/2)

BALANCE

RV402

UP

DOWN

LINE AMP

IC304

4

8

11

13

SLAT

4

8

11

75

RDS DECODER

IC1

4

14

13

X1

4.43MHz

2

16

RDS DATA

RDS CLK

C

L-CH L

MASTER
VOLUME

RV401

M

• R CH is omitted

• Signal path
: FM
: PHONO
: CD
: VIDEO

-AMP­IC408

75

75

IC409

13

IC410(1/2)

75

IC410(2/2)

F MUTE

L

SL

C

W

G

DSP

SECTION

(Page 8)

A

POWER

SECTION

(Page 11)

5.1/DVD INPUT

VIDEO

09

VIDEO 3

INPUT

MONITOR

FRONT

REAR

CENTER

WOOFER

AUDIO

VIDEO

VIDEO 1

VIDEO 2

TV/LD IN

DVD IN

OUT

OUTOUT

OUT

14

13

15

SDATA

SLAT

VIDEO -A

VIDEO-B

VIDEO-E

VIDEO-INH

SCLK

DO

60

MUTING

97

DATA IN

TUNED

STEREO

61

62

STEREO

AUSTOP

TUNER MUTE

S CLK

S DATA

57 58 56

S DATA

S CLOCK

SYSTEM

CONTROL

IC1201

LED

DRIVE

Q120

Y SWITCH

IC252

V1 O

TV

Y

TV/LD

S LAT

108

LAT

DIRECT-PASS

S-VIDEO

IN

J253

DVD

J252

VIDEO 1

C

Y

C

Y

C

VA

3

LD

5

V1 I

13

14

SW1

10

SW2

4

SW3
SW4

6

SW5

2

C SWITCH

TV

3

LD

5

V1 I

13
14

SW1
SW2

10

4

SW3

6

SW4

2

SW5

VB

V INH

VC

IC251

M O

V3 O

V1 O

M O

V3 O

15

1

7

15

1

7

Y

C

Y

C

Y

C

J252

VIDEO 1

J251

MONITOR

J298

VIDEO 3

INPUT

S-VIDEO

LED VOL

VOL DOWN
VOL UP

ANT LEV
RDS DATA

RDS CLK

S-VIDEO

OUT

B

POWER

SECTION

(Page 11)

J430

L

L

J299

L

VIDEO SELECT

IC201

13

15

11

3

7

1

9

5

V3 IN

M OUT

V1 IN

V1 OUT

V2 IN

V2 OUT

TV

LD

VCC

VEE

SW1

SW2

SW5

SW3

SW4

16

8

14

10

2

4

6

3

IC202

-5V

REG

+5V

-15V

2

81

82

83

80

J201

IN

J202

IN

J203

– 9 – – 10 –

– POWER SECTION –

L

C

W

A

INPUT

SECTION

(Page 10)

SL

VOL DATA

VOL CLK

VOL CE
AMUTE

HP RY
SP/A RY
SP/B RY

PROTECT

C RY

W RY

SUR RY

F

DSP

SECTION

(Page 8)

B

INPUT

SECTION

(Page 10)

09

STOP

P RY
ND 2

MD0

SINO

SOTO

UDATA

UCLOCK

UHREQ
USREQ

URESET

LED VOL

VOL DOWN

VOL UP

RDS DATA

RDS CLK

ANT LEV

61

U-DATA

62

U-CLOCK

60

U-HREQ

59

U-SREQ
U-RESET

58

88

LED VOL

56

VOL DOWN

55

VOL UP

54

RDS DATA
RDS CLOCK

53

AD VERTION

45

+B

SWITCH

IC414

14 15

CONTROL

8

10

9

CLK

LAT

DATA

SWITCH

IC416

3

14

CONTROL

8

CLK

SWITCH

14

CONTROL

8

CLK

19 20 49 51

SIN0

SOT0

67

2

15

109

LAT

DATA

IC415

15

10

9

LAT

DATA

MD0

MD2

AUBUS-OUT

AUBUS-IN

AD KEY IN2

AD KEY IN3

AD KEY IN4

63 39 40 41 43 44 90 70 69

FUNCTION

KEY

Q180

IN/OUT

BUFFER

MUTE

Q501,503

AD KEY IN5

AD KEY IN6

-B

+B

-B

+B

-B

LED DRIVE

Q102

D101

MUTING

POWER AMP(L)

IC501

13

VCC

14

VCC

15

VEE

IN

6

MUT

1

POWER AMP(C/W)

IC001

VCC

13

14

VCC
VEE

15

IN

8

IN

6

POWER AMP(SL)

IC701

13

VCC

14

VCC

VEE

15

6

IN

1

MUT

LED MUTE

J204
S-LINK
CTRL A1

+VE

2

NF

5

3

-VE

12

+VE

9

NF

11

-VE

2

+VE

-VE

3

2

+VE

5

NF

3

-VE

FUNCTION-DOWN

FUNCTION-UP

FUNCTION

RV101

LIMITER

Q504

LIMITER

Q505

LIMITER

Q604

LIMITER

Q605

LIMITER

Q704

LIMITER

Q705

SP-A

SP-B

72 73 74

SPEAKERS

S134

BOOSTER

Q506

BOOSTER

Q507

BOOSTER

Q606

BOOSTER

Q607

BOOSTER

Q706

BOOSTER

Q707

POWER

SYSTEM CONTROL/

MODE CONTROL

POW-KEY IN

S131

CUR DET

Q508

CUR DET

Q608

CUR DET

Q708

PROTECTOR

Q547-549

X101
4MHz

82

83

XI

XO

IC102

LED

..

1-10 14-16 87 89 91 92

...

LED DRIVE

Q103,104

106-119,122

D100,104-106,
D108-119,122

FL GRID
DRIVER

IC105

PROTECTOR

Q509,510

FL DATA

22 21 24 25

30 29

DIN

1G 19G

17-26 16-8

Q511

77

FL CLK

FL LAT

FL CLEAR

4

5

LS

CL

CLK

D OUT D IN

.

RESET

3

FL TUBE

FL101

RESET

SWITCH

Q105

29

RELAY
DRIVE

Q601

47

24 26 34

CLR

P1 P35

5-20 41-59

STOP

LAT

.

RY602

CLK

RELAY
DRIVE

Q546

RELAY
DRIVE

Q596

IMPEDANCE

SELECTOR

FL

SEGMENT

DRIVER

IC104

F1
F2

Q611

S501

98

RY501

RY502

RELAY

DRIVE
Q645

RELAY
DRIVE

Q544

RELAY

DRIVE

Q745

LAT

SIRCS

RY601

RY503

OVER LOAD SW

Q609, 610, 709, 710

RY701

+B

+32V

8

4

26

+32V REG

-B

BUFFER

R CH

R CH

R CH

Q801

SWITCH

Q613,616

+15V
+12V

Q182

I/O

IC404

+5V

1313

+5V

REG

-15V

+5V

Q101

11

12

5

CONTROL
RECEIVER

I/R
CONT
IC181

15 16

X180

7.28MHz

R CH

IC101

REMOTO

14

33

2

L

R

C

S(L)

S(R)

IC403

+12V
REG

IC1501

+5V

3

REG

+5.6V

RESET

Q181

J701

PHONES

J501

WOOFER

CNJ701

WIRELESS

SPEAKER

1

IC180

I/R

DET

TM501
FRONT

SPEAKER

CENTER

REAR

REAR

Q184,185

TM701

SPEAKER

D+5V

D+3.3V

D+3.3V

IC702

+18V

1

3

REG

+24V

IC809

+5V

13

REG

IC401
+15V

13

REG

IC402

-15V

31

REG

DELAY

+B SW

Q902

3

POWER

8

CONT
IC901

6

D184-186

LED

DRIVE

5

IC801IC8

+5V

3

REG

IC802IC8

+3.3V

3

REG

IC803
+3.3V

3

REG

SWITCH

Q747,748

-24V

D901-904

• R CH is omitted

• Signal path
: FM
: CD

1

1

D808

1

D801

D802-805

D806 F2

F1

RY901
RELAY
DRIVE

Q901

T902

POWER

TRANSFORMER

STR-DB925

T901

POWER

TRANSFORMAER

F801

F802

F803

F804

CNS901

AC

OUTLET

AC IN

– 11 –

– 12 –

STR-DB925

– DOLBY SECTION –

PD
CS

CCLK

CDTI

CDTO

SDTI1
SDTI2

SDTI3

AMP

IC1104(1/2)

D

DSP

SECTION

(Page 8)

SWDT

XLAT
SCLK

DIGITAL

A
B
C

RESET

09

67

AMP

IC1104(2/2)

OPI

TV/LD

IN

OPI

DVD

IN

OPI

MD/DAT

IN

DVD

COAX

OPT

MD/DAT

OUT

21

IC1001

OUT

IC1002

OUT

IC1003

OUT

J1001

IC1004

D IN

17
41
42
43

44

6
7
8

29

30

39

1

1

1

3

PD
CS
CCLK

CDT1
CDTO

ADC

CLOCK

GENERATOR

15
14

13

INVERTER

IC1007(1/2)

A/D,D/A CONVERTER

INTERFACE

HPF

DIGITAL IN

SELECTOR

IC1005

D4
D5
D0

4

D6

A

BC

11

10 9

A

53

IC1103

AUDIO

4

BC

IC1007(2/2)

5

5

INVERTER

DAC

DAC

DAC

DAC

26

1
2

6

LPF

LPF

LPF

LPF

BUFFER
IC1006)

L-CH

L
LS
WOOFER
CENTER

C

INPUT

SECTION

(Page 9,

10)

AMP

IC1107

27

25

24

23

9

SWDT

XLAT
SCLK

C

HVCO

57

57

31

IC1105(1/2)

57

5

AMP

IC1105(2/2)

12

13

INVERTER

IC1108(4/4)

40
41
42

MULTIPLEX

47

17

PLL

18

11

24.576MHz

AMP

IC1106

AMP

2

3

1

DATA

CONTROL

IC1108(1/4)

11

DIGITAL AIDIO INTERFACE

IC1101

INTERFACE

DEMODULATION

GENERATOR

X'TAL

OSC

26

27

X1101

ERROR CONT

IC1109

DATA

TIMING

2

1

X1301

49.152MHz

38

9

10

CONTROL

IC1108(3/4)

8

DATA

13

1

IC1102(2/2)

LOCK

ERROR

DET

MUTE

OUTPUT

4

35

30

29
34
36

VR

VR

VR

VR

3

4
5

4

5

DATA

SELECTOR

IC1108(2/4)

BUFFER

11 10

9

13

INVERTER

IC1305(2/2)

INVERTER

IC1102(1/2)

6

9

10

4

6

8

12

2
I
9

ADDRESS
DECODER

IC1304

1D

I

8D

CLK

11

1Q

8Q

30

22
26
25

27

29
28

19

I

I

12

CLOCK GENERATOR

IC1403

2CLKCK2QB

PLL CLOCK

MANAGER

DIGITAL

AUDIO

INPUT

INTERFACE

COMPRESSED

DATA

INPUT

INTERFACE

ADDRESS
DECODER

IC1303

2

1D

I

I

9

8D

CLK

CONTROLLER

8-11 14-17

1Q

I

8Q

11

1013

FRAMER

SHIFTER,

INPUT

BUFFER

.

19

I

12

DOLBY DIGITAL

AUDIO DECODER

IC1301

STC

24 BIT

DSP

PROCESSING

PARALLEL

or

SERIAL

HOST

INTERFACE

21

MEMORY

IC1302

12

A0

I

3

.

29

I

25

.

A15

23

BUFFER

IC1305(1/2)

D0

D7

CE

OE

5

13

15
17

21

22
24

OUTPUT

FORMATTER

I

.

I

SCLK

36

39
40
41
42
43
44

7

6
18
20

19

RESETRESET

AUDATA2

AUDATA1

AUDATA0

SCCLK

SCDIN
CS
INTREQ

SCDOUT

E

DSP

SECTION

(Page 7)

SRDT
ERROR

BCK

LRCK

63

ANA/DIGI

XTALERR

• R-CH is omitted

• Signal path
: FM
: CD
: DIGITAL IN
: DIGITAL OUT

– 13 – – 14 –

THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMA TIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)

For schematic diagrams.

Note:

• 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
specified.

¢

•

: internal component.

• 2 : nonflammable resistor.

• C : panel designation.

Note: The components identified by mark ! or dotted line

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

• U : B+ Line.

• V : B– Line.

• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM

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

• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc­tion tolerances.

• Circled numbers refer to waveforms.

• Signal path.

F : FM
L : AUDIO
g : VIDEO
i : SURROUND
d : PB (TAPE)
G : REC (TAPE)
p : Y
l : CHROMA
J : CD
I : PHONO
E : PB (MD/DAT)
a : REC (MD/DAT)
c : DIGITAL OUT
N : DIGIT AL IN

1

4

/

W or less unless otherwise

For printed wiring boards.

Note:

• X : parts extracted from the component side.

• Y : parts extracted from the conductor side.

•

p : parts mounted on the conductor side.

¢

•

: internal component.

• b : Pattern from the side which enables seeing.

• Indication of transistor

C

EB

These are omitted

– 15 –

WAVEFORMS
– DISPLA Y SECTION –

1

3.2Vp-p

4MHz

IC102 *™ XO

2

7.28MHz

IC103 !¡ X2

– TUNER SECTION –

1

4.33MHz

IC1 !£

4Vp-p

3.2Vp-p

– DIGIT AL SECTION –

1

4Vp-p

4MHz

IC1201 (™ XO

2

3.6Vp-p

24.576MHz

IC1101 @¶ X OUT

3

4.8Vp-p

12.28Vp-p

IC1101 @ª CLK OUT

4

4.8Vp-p

3MHz

IC1101 #¢ BCK

5

6

7

8

4.8Vp-p

48MHz

IC1101 #§ LRCK

3Vp-p

12.27Vp-p

IC1403 0 2QB

0.56Vp-p

49.152MHz

IC1305 !¡, !™

3Vp-p

12.28MHz

IC1305 6

– 16 –

STR-DB925

3-3. SCHEMATIC DIAGRAM – INPUT SECTION –

• See page 58 for IC Block Diagrams.

(Page 38) (Page 38)

(Page 41)

(Page 53)

(Page 45) (Page 45) (Page 45)

(Page 21)

(Page 29)

(Page 42) (Page 46)

(Page 30)

(Page 22)

– 17 –

– 18 –

3-4. PRINTED WIRING BOARD – INPUT SECTION –

• See page 6 for Circuit Boards Location.

(Page 48) (Page 24) (Page 31) (Page 47)

STR-DB925

(Page 23)

• Semiconductor
Location

Ref. No. Location
D301 D-8

IC301 B-2
IC302 C-2
IC303 C-8
IC304 D-5
IC401 B-11
IC402 B-11
IC403 C-11
IC404 D-3
IC405 D-10
IC406 D-10
IC407 C-11
IC414 A-9
IC415 B-9
IC416 C-9
IC501 B-7
IC601 C-5
IC701 B-5

(Page 47)

(Page 47)(Page 40)(Page 40)(Page 56)(Page 32)(Page 43)(Page 44)

Q301 E-9
Q302 D-9
Q303 D-9
Q304 C-9
Q352 D-9
Q353 C-9
Q354 C-9
Q501 A-8
Q503 A-8

– 19 – – 20 –

STR-DB925

3-5. SCHEMATIC DIAGRAM – POWER AMP SECTION –

(Page 18)

(Page 29)

(Page 29)

(Page 29)

(Page 26)

(Page 26)

(Page 18)

(Page 30)

(Page 53)

– 21 –

– 22 –

3-6. PRINTED WIRING BOARD – POWER AMP SECTION –

(Page 31)

(Page 31)

(Page 56)(Page 28)(Page 28)(Page 20)(Page 32)

(Page 32)

(Page 19)

• See page 6 for Circuit Boards Location.

STR-DB925

• Semiconductor Location

Ref. No. Location
D501 D-4

D502 D-4
D503 D-5
D504 D-5
D505 A-3
D506 A-3
D545 A-2
D546 D-2
D547 C-11
D548 C-11
D549 C-10
D551 D-10
D552 D-10
D553 D-10
D554 D-10
D555 B-3
D556 A-3
D601 D-7
D602 D-7
D603 D-7
D604 D-7

Ref. No. Location
D608 A-10

D801 B-7
D802 C-8
D803 C-8
D804 C-9
D805 C-9
D806 A-9
D807 C-6

IC809 B-10
Q504 D-5

Q505 D-5
Q506 D-4
Q507 D-5
Q508 D-6
Q509 A-3
Q510 A-2
Q511 A-3
Q546 A-10
Q547 C-11

Ref. No. Location
Q548 C-11

Q549 C-10
Q554 D-10
Q555 D-10
Q556 D-9
Q557 D-10
Q558 D-11
Q559 B-3
Q560 A-3
Q561 A-3
Q596 A-10
Q601 A-10
Q604 D-7
Q605 D-7
Q606 D-7
Q607 D-8
Q608 D-8
Q613 D-3
Q616 D-2
Q801 C-7

– 23 – – 24 –

STR-DB925

3-7. SCHEMATIC DIAGRAM – TRANS SECTION –

• See page 58 for IC Block Diagrams.

(Page 53)

(Page 22)

(Page 22)

– 25 – – 26 –

3-8. PRINTED WIRING BOARD – TRANS SECTION –

• See page 6 for Circuit Boards Location.

(Page 56)

– 27 –

STR-DB925

(Page 24)
(Page 24)

– 28 –

STR-DB925

3-9. SCHEMATIC DIAGRAM – REAR AMP SECTION –

(Page 18)

(Page 21)

(Page 18)

(Page 21)

(Page 51)

(Page 22)

(Page 22)

– 29 –

– 30 –

3-10. PRINTED WIRING BOARD – REAR AMP SECTION –

• See page 6 for Circuit Boards Location.

(Page 24) (Page 24)

STR-DB925

(Page 19)

• Semiconductor
Location

Ref. No. Location
D701 A-7

D702 A-7
D703 A-6
D704 A-6
D751 A-2
D752 A-3
D753 A-2
D754 A-2

Q704 A-6
Q705 A-6
Q706 A-7
Q707 A-5
Q708 A-7
Q754 A-2
Q755 A-2
Q756 A-3
Q757 A-2
Q758 A-1

(Page 23) (Page 56) (Page 19) (Page 24)

• Semiconductor
Location

Ref. No. Location

D543 A-4
D605 B-2
D606 B-2
D607 A-2
D649 B-4
D705 A-5
D706 A-5
D749 B-6

IC702 B-1
Q544 A-4

Q609 B-2
Q610 B-2
Q611 A-2
Q645 B-2
Q709 A-5
Q710 A-5
Q745 A-3
Q747 B-2
Q748 B-1

– 31 – – 32 –