Sony STR-DB725, STR-DB825 Service Manual

MICROFILM

STR-DB725/DB825

SERVICE MANUAL

Photo: STR-DB825

SPECIFICATIONS

AEP Model

UK Model

— Continued on next page —

FM STEREO/FM-AM RECEIVER

– 1 –

TABLE OF CONTENTS

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

2. GENERAL .......................................................................... 4

3. DIAGRAMS

3-1. Circuit Boards Location........................................................5

3-2. Block Diagrams

• Main Section.......................................................................7

• Power Section .....................................................................9

3-3. Schematic Diagram – Video Input Section – ...................... 13

3-4. Printed Wiring Board – Video Input Section – ................... 15

3-5. Schematic Diagram – Input Section – ................................ 17

3-6. Printed Wiring Board – Input Section – .............................. 19

3-7. Schematic Diagram – S-Video Section – ............................ 21

3-8. Printed Wiring Board – S-Video Section – ......................... 23

3-9. Schematic Diagram – Speaker Section – ............................ 25

3-10. Printed Wiring Board – Speaker Section –...................... 27

3-11. Printed Wiring Board – Display Section – ....................... 29

3-12. Schematic Diagram – Display Section – ......................... 31

3-13. Schematic Diagram – Front Panel Section – ................... 33

3-14. Printed Wiring Board – Front Panel Section – ................. 35

3-15. Schematic Diagram – Power AMP Section –.................. 37

3-16. Printed Wiring Board – Power AMP Section –................ 39

3-17. Schematic Diagram – Trans Section – ............................ 41

3-18. Printed Wiring Board – Trans Section –........................... 42

3-19. IC Block Diagrams ...........................................................43

3-20. IC Pin Functions ...............................................................46

4. EXPLODED VIEWS

4-1. Case and Back Panel Section.............................................. 48

4-2. Front Panel Section ............................................................. 49

4-3. Chassis Section ................................................................... 50

5. ELECTRICAL PARTS LIST ........................................ 51

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.

MODEL IDENTIFICATION
— BACK PANEL —

– 2 –

Parts No.

PARTS No. MODEL

4-900-493-0π
4-900-493-1π

DB725
DB825

SECTION 1

SERVICING NOTE

FACTORY SET

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

Procedure:

While pressing the < button and BASS BOOST button together, press the 1/u button to turn on the power.
“FACTORY” will be displayed and factory settings executed.

INITIALIZATION

Mode which erases all the preset settings of the unit.
Use this mode when returning the unit to the customer.

Procedure:

While pressing the MEMORY button and MUTING button together, press the 1/u button to turn on the power.
“ALL CLEAR” will be displayed and initialization executed.

FLUORESCENT INDICATOR TUBE AND LED LIGHTING CHECK

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

Procedure:

While pressing the ∨ button and BASS BOOST button together, press the 1/u button to turn on the power.
The whole fluorescent display tube lights up.
The fluorescent display tube and LED light up in the following sequence each time the FUNCTION knob is rotated.

The fluorescent display tube: All light up
LED: VIDEO 1 , VIDEO 3 , TAPE/MD ,

5.1/DVD INPUT , MASTER VOLUME
and SURROUND light

Turn the FUNCTION knob

The fluorescent display tube: Light up partially (1)
LED: TV/LED , CD , PHONO ,

TONE , BASS/TREBLE and
MASTER VOLUME light

Turn the FUNCTION knob

The fluorescent display tube: Light up partially (2)
LED: VIDEO 2 , TUNER , BASS BOOST ,

INDEX , MASTER VOLUME and
MUTING light

Turn the FUNCTION knob

The fluorescent display tube: All lights out
LED: All lights out

Turn the FUNCTION knob

KEY CHECK

Mode for checking key input.

Procedure:

Turn on the po wer by pr essing the 1/u button w hile pressing the ∧ button and the BASS BOOST button. “REST 25 KEY” is displayed.
The count decreases each time the button is pressed.
Buttons counted once will not be couned again.
“REST 00 KEY” is displayed when all the buttons are pressed.

– 3 –

Front Panel Descriptions

SECTION 2

GENERAL

1

3

465

45

44
43

4142

LOCATION OF PARTS AND CONTROLS

1 1/u (power) switch
2 DISPLAY button
3 FM/AM button
4 VIDEO 1 indicator
5 VIDEO 2 indicator
6 VIDEO 3 indicator
7 TV/LD indicator
8 TAPE/MD indicator
9 Display window
10 CD indicator
11 SURROUND indicator
12 TUNER indicator
13 PHONO indicator
14 5.1/DVD INPUT indicator

TONE indicator
BASS BOOST indicator

15 MASTER VOLUME knob
16 MUTING button and indicator
17 FUNCTION knob
18 MODE switch
19 BALANCE knob
20 SOUND FIELD ON/OFF button
21 SOUND FIELD MODE button
22 SOUND FIELD GENRE button

782

3033343536

10 11 13 14

28

29 1718192122 2027

129

26

232425313237383940

23 BASS BOOST button
24 TONE ON/OFF button
25 5.1/DVD INPUT button
26 BASS/TREBLE indicator
27 INDEX indicator
28 SET UP button
29 Digital Processing Controls
30 CURSOR MODE button
31 RDS EON button
32 RDS PTY button
33 VIDEO 3 INPUT AUDIO R connecot
34 VIDEO 3 INPUT AUDIO L connecot
35 VIDEO 3 INPUT VIDEO connecot
36 VIDEO 3 INPUT S-VIDEO connecot
37 TUNING + button
38 TUNING – button
39 FM MODE button
40 MEMORY button
41 PRESET TUNING + button
42 PRESET TUNING – button
43 SHIFT button
44 PHONES jack
45 SPEAKERS selector switch

15

16

– 4 –

3-1. CIRCUIT BOARDS LOCATION

d

SECTION 3

DIAGRAMS

SP board

S VIDEO board

H.P board

DISPLAY board

VIDEO (3) board

AMP board

BALANCE board

STANDBY board

VIDEO boar

SURR board

VOLUME board

STANDBY (2) board

REAR AMP board

CONNECTOR board

SP SWITCH

board

SW board

INPUT board

FUNCTION board

– 5 –

3-2. BLOCK DIAGRAMS

L

24

IF DATA

KEY 4/SMETER

FM

AM

FM

75Ω

AM

DO

ASTOP

TMUTE

STEREO

DATA

CLK

CE

L OUT

R OUT

TUNER UNIT

TUNER UNIT IS SUPPLIED AS THE ASSEMBLED BLOCK

DO

AUTO STOP

TMUTE

STEREO

S DATA

S CLK

S LAT

R CHR CH

RDS

: FM

: CD

• Signal Path

• RCH is omitted

PHONO

LCD

J201

LIN

LREC OUT

J202

LFRONT

LREAR

J203

WOOFER

5.1/DVD INPUT

TAPE/MD

M OUT

1

J201

IN

MONITOR

J202

J203

5.1/DVD
INPUT

TV/LD

VIDEO 2

OUT

IN

VIDEO 1

OUTOUT

OUT

V1 IN

13

V1 OUT

15

V2 IN

9

V2 OUT

11

TV

3

LD

5

8

VEE

16

VCC

14

SW1

10

SW2

2

SW5

4

SW3

6

SW4

3 2

VIDEO SELECT

IC201

-5V

REG

IC202

-15V

+5V

: VIDEO

3

2

1

10

9

6

4

11

8

CONTROL

CE13CLK

15DI14

AUDIO SELECT

IC302

MUTE
Q300

S LAT

S CLK

S DATA

CONTROL

EN45CLK47DATA

46

D LAT

S CLK

S DATA

31

LINE AMP

IC404

9

L OUT

S OUT

C OUT

41

39

38

MATRIX DECODER

IC401

DOLBY PROLOGIC

11

13

31

EQ AMP

IC303

30
29
27
26

28

25

CONTROL

LAT13CLK15DI

14

SELECTOR

IC403

S LAT

S CLK

S DATA

20k

L.P.F

ADM

5k/7k
L.P.F

VOL/

MUTE

DEC

EN4CLK

2DI3

D LAT

S CLK

S DATA

22

20

PROCESSOR

IC400

SURROUND

SL OUT

L OUT

24
23

22

MUTE SW

Q411

3
2

1

31

MUTE
Q304

57

MUTE
Q305

IC306

IC304

IC305

L.P.F

MUTE
Q302

4

2

3

6

5

BASS

TREBLE

TONE CONTROL

IC502

LEVEL SHIFT

STB10CLK8DI

9

T LAT

S CLK

S DATA

BOOST

DET

Q501,502

Q414

+5V

RY301

RELAY
DRIVE

Q308

RV401

VOLUME

RV402

BALANCE

L

C

W

SL

A

POWER

SECTION

M

UP

DOWN

V-A

2

SYSTEM
CONTROL
IC103(1/2)

V-B

3

V-E

4

V INH

27

09

21

AUTO STOP

23

STEREO

22

TUNER MUTE

RDS DATA

RDS CLK

S DATA

S CLK

S LAT

DO

AUTO STOP

STEREO

TMUTE

19

S DATA

18

15 38

S CLOCK

20

S LATCH

9

D LATCH

17

T LATCH

D LAT

T LAT

30

RDS SM

52

VOL +

51

VOL–

3
2

8
7

VOL

MOTOR

IC106

DOWN

6

S MUTE

49

BASS BOOST

41

DIRECT PASS

LED SW

Q108

LED SW

Q143

D136

B

POWER

SECTION

: PHONO

CENTER

J299

VIDEO

LAUDIO

VIDEO 3

INPUT

V3 IN

7

1

7

10

9

4

11

CONTROL

CE

13

CLK15DI

14

AUDIO SELECT

IC300

S LAT

S CLK

S DATA

6 8

LTV/LD

L

J300

VIDEO2

AUDIO IN

AUDIO IN

LAUDIO OUT

L

VIDEO1

AUDIO IN

L

31

LINE AMP

IC301

BASS

BOOST

UP

Y

V1 O

3

VIDEO 1

S-LINK

CTRL A1

J204

LED
DRIVE
Q150

13

14
10

4
6

TV

15

1

7

V1 I

SW1
SW2
SW3
SW4

V3 O

M O

Y SWITCH

IC252

C

Y

J252

VIDEO 1

Y

C

C

Y

C SWITCH

IC251

C

Y

C

J251

MONITOR

J298

VIDEO 3

INPUT

S-VIDEO

TV/LD

J253

J252

55

VOL LED

CTRL A1 OUT

36

IN/OUT

BUFFER

Q1101

CTRL A1 IN

37

J301

V1 O3

13
14

10

4
6

TV

15

1

7

V1 I
SW1

SW2
SW3
SW4

V3 O

M O

13

V1 I

C

Y

5.1/DVD
INPUT

S-VIDEO

IN

3

TV

VA

VB

VC

V INH

SIRCS

CTRL A1

P RY

RDS DATA

RDS CLK

RDS SM

4

2

1413

RDS DECODER

RDS DATA

RDS CLK

X450

4.43MHz

IC452

16

S-VIDEO

OUT

AUDIO OUT

AUDIO OUT

VIDEO

– MAIN SECTION –

STR-DB725/DB825

– 7 –

– 8 –

STR-DB725/DB825

– POWER SECTION –

L

C

W

A

MAIN

SECTION

SL

P RY

B

MAIN

SECTION

CTRL A1

12

X101

4.19MHz

X1

11

X2

09

KEY1

33

FUNCTION

KEY

S102-S111

KEY2

32

FUNCTION

KEY

S115-122

+B

–B

+B

–B

+B

–B

MUTE

Q691,692

8

AC MUTE

KEY3

31

FUNCTION

KEY

S114, S125-130

POWER AMP(L)

IC601

13 VCC

+VE

VCC

14
15

VEE

NF

IN

6

MUT

1

–VE

POWER AMP(C/W)

IC001

13 VCC

+VE

14 VCC

VEE

15

IN

8

NF

IN

6

–VE

POWER AMP(SL)

IC701

13 VCC

VCC

+VE

14

VEE

15

IN

NF

6

1

MUT

–VE

MUTING LED

59

D116

MUTING

2

5

3

12

9

11

2+VE
3–VE

2

5

3

FUNCTION

53

RV101

LIMITER

Q504

LIMITER

Q505

LIMITER

Q604

LIMITER

Q605

LIMITER

Q704

LIMITER

Q705

SYSTEM CONTROL/

MODE CONTROL

IC103(2/2)

RE B54RE A

BOOSTER

Q506

BOOSTER

Q507

BOOSTER

Q606

BOOSTER

Q607

BOOSTER

Q706

BOOSTER

Q707

56

S151

POWER

CUR DET

CUR DET

CUR DET

POWER

Q508

Q608

Q708

PROTECTOR

Q547-549

47

PROTECTOR

TONE60SURR61INDEX

62

LED DRIVE

PROTECTOR

PROTECTOR

DIRECT PASS585.1 INPUT

57

Q103,104

Q103,104

D111,135D115-113

Q509,510

Q609,610

TUNER64VIDEO1

70

D124

Q511

Q611

MD/TAPE

PHONO63TV/DBS

66

67

VIDEO 2

69

44

FRONT RY

CD

65

131

S155

SPEAKERS

VIDEO 3

68

RY602
RELAY
DRIVE

Q601

A+B

OFF

A

B

50

SP OFF

P1 17

.

71 78

80 88

FL101

FL TIBU

F2 F1

43

G1 12

100 89

S(L)

S(R)

J701

PHONES

• RCH is omitted

L

R

C

CENTER

J501

WOOFER

TM501
FRONT

SPEAKER

REAR

TM701

SPEAKER

• Signal Path

:FM

:CD

CNJ701

WIRELESS

REAR

SPEAKER

IC702

+18V

3

REG

IC809

IC809

+5V

3

1

REG

+5.6V

IC107

3

DET

IC801

+15V

3

1

REG

IC803

-15V

1

3

REG

DELAY
+B SW

Q902

3

POWER

CONT
IC901

6

Q129,130

LED

I/R

DRIVE

IC451

+12V

1

REG

RESET

Q107

1

+24V

-24V

-30V

D101-103

SWITCH

Q747,748

D802-805

REG
Q801

RELAY
DRIVE

Q901

D901-904

58

D801

D806 F2

RY901

T902

F801

T901

F802

F803

F804

F1

F901

F903

CNJ909

CNP901

AC IN

R CH

RY501
RELAY
DRIVE

Q546

RY502
RELAY
DRIVE

Q596

RY601

RELAY
DRIVE

Q645

RY503

RELAY
DRIVE

Q544

OVER LOAD SW

Q609, 610, 709, 710

Q611

RY701

RELAY
DRIVE

Q745

+B

-B

S501

SIRCS

RESET

STOP

8

4

48

26

10

39

Q106

BUFFER

DB825

IMPEDANCE

SELECTOR

45

42

POWER RY

SUR RY

MIX SUB RY

CENTER RY

CTRL A1 LAT

28

R CH

R CH

R CH

SWITCH

Q613,616

+15V
+12V

IC450

+5V

3

1

+5V

-15V

Q105

I/O

RESET

Q101

11

12

5

REG

REMOTO
CONTROL
RECEIVER

Q102

I/R
CONT
IC102

15 16

X102

7.28MHz

IC101

14

33

2

– 9 – – 10 –

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/MD)
G : REC (T APE/MD)
p : Y
l : CHROMA
J : CD
I : PHONO

1

4

/

W or less unless otherwise

WA VEFORMS
– DISPLA Y SECTION –

1

3.8Vp-p

7.28MHz

IC102 !§ XOUT

2

4.3Vp-p

4.19MHz

IC103 !¡ X2

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

– 11 –

STR-DB725/DB825

3-3. SCHEMATIC DIAGRAM – VIDEO INPUT SECTION –

• See page 43 for IC Block Diagrams.

(Page 21)

(Page 21)

(Page 32)

(Page 17)

– 13 – – 14 –

3-4. PRINTED WIRING BOARD – VIDEO INPUT SECTION –

• See page 5 for Circuit Boards Location.

STR-DB725/DB825

(Page 30)

(Page 23)

(Page 23)

(Page 19)

– 15 – – 16 –

STR-DB725/DB825

3-5. SCHEMATIC DIAGRAM – INPUT SECTION –

• See page 43 for IC Block Diagrams.

(Page 22)

(Page 21,

22)

(Page 22)

(Page

37)

(Page

25)

(Page

26)

(Page 32)

– 17 –

(Page

14)

(Page

37)

(Page 31, 32)

(Page 33)

– 18 –

3-6. PRINTED WIRING BOARD – INPUT SECTION –

• See page 5 for Circuit Boards Location.

(Page 15)

(Page 39)

(Page 27)

(Page 27)

(Page 40)

STR-DB725/DB825

• Semiconductor
Location

Ref. No. Location
D301 D-7

D401 F-8 D402 E-10

IC001 C-7 IC301 D-5 IC302 B-2 IC303 C-2 IC304 E-8 IC305 E-7 IC306 D-10 IC450 B-11 IC451 B-10 IC452 F-1 IC502 D-11 IC601 B-7 IC701 B-5 IC801 B-9 IC803 B-10

Q300 F-8 Q301 E-8 Q302 E-6 Q303 E-5 Q304 E-6 Q305 D-6 Q411 F-7 Q414 E-11 Q501 C-10 Q502 B-10 Q551 E-10 Q552 E-11 Q691 B-8 Q692 B-8 Q3008 D-6

(Page

24)

(Page

24)

(Page 30)

(Page 30)

(Page 24)

(Page 35)

– 19 – – 20 –

STR-DB725/DB825

3-7. SCHEMATIC DIAGRAM – S-VIDEO SECTION –

• See page 43 for IC Block Diagrams.

(Page 18)

– 21 –

(Page 14)

(Page 14)

(Page 18)

(Page 18)

– 22 –

3-8. PRINTED WIRING BOARD – S-VIDEO SECTION –

• See page 5 for Circuit Boards Location.

STR-DB725/DB825

(Page 15)

(Page 15)

(Page 19)

(Page 19) (Page 19)

– 23 – – 24 –