Sony STR-DB925 User manual

– 1 –
MICROFILM
AEP Model
UK Model
Australian Model
SPECIFICATIONS
SERVICE MANUAL
FM STEREO/FM-AM RECEIVER
STR-DB925
— Continued on next page —
Photo:BLACK
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– 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.
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– 3 –
SECTION 1
SERVICING NOTE
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 INDICATORTUBE AND LED LIGHTING CHECK
Mode which lights up the whole fluorescent indicator tube or partially.
Procedure:
With the power off, press the 1/u button while pressing the SET UP and SOUND FIELD MODE buttons to turn 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 REMOVINGTHE 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.
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 – RearAMP Section – ........................29
3-10. Printed Wiring Board – Rear AMP Section – ..................31
3-11. Schematic Diagram – Display Section –......................... 33
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. EXPLODEDVIEWS
4-1. Case and Back Panel Section.............................................. 68
4-2. Front Panel Section .............................................................69
4-3. Chassis Section ................................................................... 70
5. ELECTRICAL PARTS LIST ........................................ 71
TABLE OF CONTENTS
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– 4 –
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
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 :
1DSP1 BOOT ERROR CHECK (DSP1:IC1301)
µ
2DSP1 REPLAY ERROR CHECK
µ
3DSP2 RAM ERROR CHECK (DSP2:IC1402 RAM:IC1402)
µ
4DSP2 REPLAY ERROR CHECK
Refer to Table 2 if errors occur and perform the repairs.
Table-2 Display of Errors and Main Causes
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 external equipment connected at 1. will be assigned to the outputs as
shown in Table 1.
When “DSP NO ERROR” is displayed, the reference 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 3of 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.
Output To
FRONT L-ch + CENTER + REAR L-ch
FRONT R-ch + WOOFER + REAR R-ch
Possible Cause and Countermeasure
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
Error Message
DSP1 BOOT ERROR
DSP1 REPLY ERROR
DSP2 RAM ERROR
DSP2 REPLY ERROR
Input Signal
FRONT L-ch
FRONT R-ch
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– 5 –
Front Panel Descriptions
SECTION 2
GENERAL
LOCATION OF PARTS AND CONTROLS
11/u (power) switch
2VIDEO 1 indicator
3VIDEO 2 indicator
4VIDEO 3 indicator
5DVD indicator
6TV/LD indicator
7MULTI CHANNEL DECODING indicator
8TAPE indicator
9MD/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
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
78
234 65 110 11 13
14
15
129
45
2629
17
18
21 19 22 20
27
28
30
33343536 2324
2531
3237383940
41
42 164344
46
47
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– 6 –
SECTION 3
DIAGRAMS
3-1. CIRCUIT BOARDS LOCATION
S-VIDEO board
REG board
DISPLAY board
AMP board
LED board
INPUT board
DIGITAL board
SP-S board
JOINT board
H.P board
AC board
BALANCE board
VIDEO board
AUDIO board
TUNER board
5.1 IN board
D. IN/OUT board
ROTARY board
SW board
F-VIDEO board
SP SW board
VOLUME board
REAR AMP board
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– 69 –
SECTION 4
EXPLODEDVIEWS
4-1. CASE AND BACK PANEL SECTION
NOTE:
• Items marked “*” are not stocked since they are
seldom required for routine service. Some delay
should be anticipated when ordering these items.
• Color Indication ofAppearance Parts Example:
KNOB, BALANCE (WHITE)
Â
Cabinet’s color
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
The components identified by
mark !or dotted line with mark
!are critical for safety.
Replace only with part number
specified.
*13 3-703-244-00 BUSHING (2104), CORD
!14 1-769-744-11 CORD, POWER
15 X-4949-523-1 FOOT ASSY (F50180S)
16 4-970-124-01 CUSHION (F50180S)
*17 1-670-022-11 5.1 IN BOARD
18 1-769-876-11 WIRE (FLAT TYPE)(7 CORE)
19 4-947-010-01 SCREW, FEEDER FIXED
20 X-3375-592-1 KNOB (VOL) ASSY (BLACK)
20 X-4950-340-1 KNOB (VOL) ASSY (SILVER)
21 4-998-207-11 INDICATOR (VOL)
22 3-350-426-01 SPRING, RING
!CNJ909 1-526-794-11 OUTLET, AC
1 4-210-291-01 SCREW (CASE 3 TP2)(BLACK)
1 4-210-291-11 SCREW (CASE 3 TP2)(SILVER)
*2 X-4950-431-1 CASE ASSY (BLACK)
*2 X-4950-432-1 CASE ASSY (SILVER)
*3 1-670-001-11 AUDIO BOARD
*4 A-4414-113-A SP-S BOARD, COMPLETE
*5 1-670-004-11 S-VIDEO BOARD
6 1-769-904-11 WIRE (FLAT TYPE)(9 CORE)
*7 1-670-003-11 VIDEO BOARD
8 1-693-409-11 TUNER
*9 4-900-493-21 PANEL, BACK
*10 1-670-029-11 D.IN/OUT BOARD
*11 1-670-000-11 TUNER BOARD
*12 A-4414-117-A DIGITAL BOARD, COMPLETE
• The mechanical parts with no reference number in
the exploded views are not supplied.
• Hardware(# mark) listand accessoriesand packing
materials are given in the last of this parts list.
11
1
3
4
5
67
8
9
10
11
17
18
19
#2
#2 #2#2
#2
#2
#2
#2
#2
Front panel
#2
#1
#2 #1
#
2
#2
#2
#2
#2
CNJ909
not supplied
#2
15
16
15
16 12
13
14
2
21
20
22
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– 70 –
4-2. FRONT PANEL SECTION
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
*65 1-670-017-11 SW BOARD
66 4-900-565-01 INDICATOR (2)
67 4-900-491-01 BUTTON (MUTE)
*68 1-670-023-11 ROTARY BOARD
69 4-951-620-01 SCREW (2.6X8), +BVTP
*70 A-4414-097-A DISPLAY BOARD, COMPLETE
71 1-773-163-11 WIRE (FLAT TYPE)(21 CORE)
72 1-769-961-11 WIRE (FLAT TYPE)(11 CORE)
73 X-3375-588-1 ESCUTCHEON (WIN) ASSY
74 3-703-466-00 SPRING (6600)
75 4-942-568-41 EMBLEM (NO.5), SONY
76 4-900-577-01 SPRING (1)(R)
77 4-900-576-01 SPRING (1)(L)
*78 1-670-024-11 LED BOARD
79 4-999-431-01 LENS, LED
*80 4-921-941-01 CUSHION (FL)
*81 4-990-797-01 HOLDER (FL)
FL101 1-517-781-11 INDICATOR TUBE, FLUORESCENT
51 4-900-570-01 ESCUTCHEON (A-LID)(BLACK)
51 4-900-570-11 ESCUTCHEON (A-LID)(SILVER)
52 4-900-492-01 KNOB (LID)
*53 4-900-569-01 ESCUTCHEON (M-LID)
*54 4-900-579-01 COVER (STI)
55 X-4948-601-1 KNOB (FUNC) ASSY (BLACK)
55 X-4950-280-1 KNOB (FUNC) ASSY (SILVER)
56 4-900-500-01 KNOB (BAL)(BLACK)
56 4-900-500-11 KNOB (BAL)(SILVER)
57 4-900-568-01 PANEL, FRONT (BLACK)
57 4-900-568-31 PANEL, FRONT (SILVER)
58 4-900-566-01 WINDOW
59 4-900-572-11 FULCRUM (L)
60 4-900-571-11 FULCRUM (R)
61 X-3375-590-1 BASE ASSY, PANEL (BLACK)
61 X-4950-278-1 BASE ASSY, PANEL (SILVER)
62 4-900-563-01 BUTTON (5)(BLACK)
62 4-900-563-11 BUTTON (5)(SILVER)
63 4-957-383-01 KNOB (F14)
*64 1-670-018-11 SP SW BOARD
51
#3
#2
52 53
58
59
61
62
63
64
65
54
66
67 69
68
76
77
69
69
73 78
FL101
70 71
80
80 81
69
69 72
69
60
56
5574
75
57
79
69
#3
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– 71 –
4-3. CHASSIS SECTION
Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark
Q506 8-749-010-25 IC MN2488-OPY-M
Q507 8-749-010-26 IC MP1620-OPY-M
Q555 8-729-209-15 TRANSISTOR 2SD2012
Q556 8-749-010-25 IC MN2488-OPY-M
Q557 8-749-010-26 IC MP1620-OPY-M
Q605 8-729-209-15 TRANSISTOR 2SD2012
Q606 8-749-010-25 IC MN2488-OPY-M
Q607 8-749-010-26 IC MP1620-OPY-M
Q705 8-729-209-15 TRANSISTOR 2SD2012
Q706 8-749-010-25 IC MN2488-OPY-M
Q707 8-749-010-26 IC MP1620-OPY-M
Q755 8-729-209-15 TRANSISTOR 2SD2012
Q756 8-749-010-25 IC MN2488-OPY-M
Q757 8-749-010-26 IC MP1620-OPY-M
!T901 1-431-889-11 TRANSFORMER, POWER
*101 1-670-006-11 H.P BOARD
*102 1-670-021-11 F-VIDEO BOARD
103 4-900-386-01 SCREW
*104 1-670-020-11 BALANCE BOARD
*105 1-670-019-11 VOLUME BOARD
106 3-703-397-01 STOPPER, WIRING
*107 A-4414-095-A INPUT BOARD, COMPLETE
*108 4-924-098-31 HOLDER, PC BOARD
109 1-773-285-11 WIRE (FLAT TYPE)(29 CORE)
110 3-905-609-11 SCREW (TRANSISTOR)
*111 A-4414-112-A REAR AMP BOARD, COMPLETE
*112 1-669-998-11 AC BOARD
*113 A-4414-109-A REG BOARD, COMPLETE
*114 A-4414-094-A AMP BOARD, COMPLETE
*115 1-670-032-11 JOINT BOARD
Q505 8-729-209-15 TRANSISTOR 2SD2012
The components identified by mark !or dotted
line with mark !are critical for safety.
Replace only with part number specified.
Q706 not supplied
not supplied
not supplied
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
#2
not supplied
T901
Q705
Q707
Q756
Q755
Q757
Supplied with
J701
Supplied with
RV401
not supplied
not
supplied
101
102
104 105
107
109
110
110
111
112
113
108
110
103
114
115
Q557
Q555
Q556
Q607
Q605
Q606
Q507 Q506
Q505
106
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