STR-DB725, STR-DB825 - Sony Audio Service Manual (repair manual)

str-db725, str-db825 service manual
Model
STR-DB725 STR-DB825
Pages
46
Size
6.6 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
str-db725-str-db825.pdf
Date

Read Sony STR-DB725 / STR-DB825 Service Manual online

– 1 –
MICROFILM
AEP Model
UK Model
SPECIFICATIONS
SERVICE MANUAL
FM STEREO/FM-AM RECEIVER
STR-DB725/DB825
— Continued on next page —
Photo: STR-DB825
– 2 –
SAFETY-RELATED COMPONENT WARNING !!
COMPONENTS IDENTIFIED BY MARK 
!
 OR DOTTED 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.
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.
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
Parts No.
PARTS No.
MODEL
MODEL IDENTIFICATION
— BACK PANEL —
4-900-493-0π
4-900-493-1π
DB725
DB825
– 3 –
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.
KEY CHECK
Mode for checking key input.
Procedure:
Turn on the power by pressing the  1/u  button while 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.
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
Turn the  FUNCTION  knob
Turn the  FUNCTION  knob
Turn the  FUNCTION  knob
The fluorescent display tube: Light up partially (1)
LED: TV/LED  ,  CD  ,  PHONO  ,
TONE  ,  BASS/TREBLE  and  
MASTER VOLUME  light
The fluorescent display tube: Light up partially (2)
LED: VIDEO 2  ,  TUNER  ,  BASS BOOST  ,
INDEX  ,  MASTER VOLUME  and  
MUTING  light
The fluorescent display tube: All lights out
LED: All lights out
– 4 –
Front Panel Descriptions
SECTION 2
GENERAL
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
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
7
8
2 3
4
6
5
1
10 11
13 14
15
12
9
45
26
29
17
18
19
21
22
20
27
28
30
33
34
35
36
23
24
25
31
32
37
38
39
40
41
42
16
43
44
Page of 46
Display

Download Sony STR-DB725 / STR-DB825 Service Manual (Repair Manual)

Here you can read online and download Sony STR-DB725 / STR-DB825 Service Manual in PDF. STR-DB725 / STR-DB825 service manual will guide through the process and help you recover, restore, fix, disassemble and repair Sony STR-DB725 / STR-DB825 Audio. Information contained in service manuals typically includes schematics / circuit diagrams, wiring diagrams, block diagrams, printed wiring boards, exploded views, parts list, disassembly / assembly, pcb.