Sony STR-DB725 / STR-DB825 Service Manual ▷ View online
– 5 –
SECTION 3
DIAGRAMS
3-1. CIRCUIT BOARDS LOCATION
SURR board
S VIDEO board
STANDBY (2) board
DISPLAY board
AMP board
INPUT board
SP board
CONNECTOR board
H.P board
STANDBY board
BALANCE board
VIDEO board
FUNCTION board
SW board
VIDEO (3) board
SP SWITCH
board
VOLUME board
REAR AMP board
– 8 –
STR-DB725/DB825
3-2. BLOCK DIAGRAMS
– MAIN SECTION –
– 7 –
L
24
IF D
A
T
A
KEY 4/SMETER
FM
AM
FM
75
Ω
AM
DO
AST
OP
TMUTE
STEREO
D
ATA
CLK
CE
L OUT
R OUT
TUNER UNIT
TUNER UNIT IS SUPPLIED AS THE ASSEMBLED BLOCK
DO
A
U
T
O
ST
OP
TMUTE
STEREO
S
D
ATA
S CLK
S LA
T
R CH
R CH
RDS
: FM
: CD
• Signal Path
• RCH is omitted
PHONO
L
CD
J201
L
IN
L
REC OUT
J202
L
FRONT
L
REAR
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
OUT
OUT
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
CE
13
CLK
15
DI
14
AUDIO SELECT
IC302
MUTE
Q300
S LA
T
S CLK
S
D
ATA
CONTROL
EN
45
CLK
47
D
ATA
46
D LA
T
S CLK
S
D
ATA
3
1
LINE AMP
IC404
9
L OUT
S OUT
C OUT
41
39
38
MATRIX DECODER
IC401
DOLBY PROLOGIC
11
13
3
1
EQ AMP
IC303
30
29
27
26
28
25
CONTROL
LA
T
13
CLK
15
DI
14
SELECTOR
IC403
S LA
T
S CLK
S
D
ATA
20k
L.P.F
ADM
5k/7k
L.P.F
VOL/
MUTE
DEC
EN
4
CLK
2
DI
3
D LA
T
S CLK
S
D
ATA
22
20
PROCESSOR
IC400
SURROUND
SL OUT
L OUT
24
23
22
MUTE SW
Q411
3
2
1
3
1
MUTE
Q304
5
7
MUTE
Q305
IC306
IC304
IC305
L.P.F
MUTE
Q302
4
2
3
6
5
BASS
TREBLE
TONE CONTROL
IC502
LEVEL SHIFT
STB
10
CLK
8
DI
9
T LA
T
S CLK
S
D
ATA
BOOST
DET
Q501,502
Q414
+5V
RY301
RELAY
DRIVE
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
A
U
T
O
ST
OP
23
STEREO
22
TUNER MUTE
RDS D
A
T
A
RDS CLK
S
D
ATA
S CLK
S LA
T
DO
A
U
T
O
ST
OP
STEREO
TMUTE
19
S
D
ATA
18
15 38
S CLOCK
20
S LA
TCH
9
D LA
TCH
17
T LA
TCH
D LA
T
T LA
T
30
RDS SM
52
V
OL +
51
V
OL–
3
2
8
7
VOL
MOTOR
IC106
DOWN
6
S MUTE
49
BASS BOOST
41
DIRECT P
ASS
LED SW
Q108
LED SW
Q143
D136
B
POWER
SECTION
: PHONO
CENTER
J299
VIDEO
L
AUDIO
VIDEO 3
INPUT
V3 IN
7
1
7
10
9
4
11
CONTROL
CE
13
CLK
15
DI
14
AUDIO SELECT
IC300
S LA
T
S CLK
S
D
ATA
6
8
L
TV/LD
L
J300
VIDEO2
AUDIO IN
AUDIO IN
L
AUDIO OUT
L
VIDEO1
AUDIO IN
L
3
1
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 O
3
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 D
A
T
A
RDS CLK
RDS SM
4
2
14
13
RDS DECODER
RDS DATA
RDS CLK
X450
4.43MHz
IC452
16
S-VIDEO
OUT
AUDIO OUT
AUDIO OUT
VIDEO
– 9 –
– 10 –
STR-DB725/DB825
– POWER SECTION –
RELAY
DRIVE
Q601
LIMITER
Q504
14
5
15
6
1
2
3
VEE
VCC
IN
MUT
+VE
NF
–VE
13 VCC
POWER AMP(L)
IC601
L
+B
–B
LIMITER
Q505
BOOSTER
Q506
BOOSTER
Q507
CUR DET
Q508
PROTECTOR
Q509,510
Q511
LIMITER
Q604
9
15
12
11
VEE
IN
+VE
NF
–VE
13 VCC
POWER AMP(C/W)
IC001
C
+B
–B
LIMITER
Q605
BOOSTER
Q606
BOOSTER
Q607
CUR DET
Q608
PROTECTOR
Q609,610
Q611
LIMITER
Q704
MUTE
Q691,692
14
5
15
6
1
2
3
VEE
VCC
IN
MUT
+VE
NF
–VE
13 VCC
POWER AMP(SL)
IC701
SL
+B
–B
LIMITER
Q705
BOOSTER
Q706
BOOSTER
Q707
CUR DET
Q708
8
RY602
RELAY
DRIVE
Q546
RY501
RELAY
DRIVE
Q596
RY502
B
A
A+B
OFF
S155
SPEAKERS
RELAY
DRIVE
Q645
RY601
RELAY
DRIVE
Q745
RY701
RELAY
OVER LOAD SW
Q609, 610, 709, 710
DRIVE
Q544
Q611
RY503
RELAY
DRIVE
Q901
RY901
J501
C
S(L)
S(R)
R CH
R CH
WIRELESS
REAR
SPEAKER
CNJ701
CENTER
WOOFER
J701
PHONES
TM701
FRONT
SPEAKER
TM501
R CH
R CH
POWER
CONT
IC901
5
8
3
6
DELAY
+B SW
Q902
SWITCH
Q747,748
D801
SWITCH
Q613,616
PROTECTOR
Q547-549
D806
F2
F1
+5.6V
F801
F802
D802-805
+B
-B
IMPEDANCE
SELECTOR
8
4
S501
F901
F903
D901-904
DB825
CNJ909
CNP901
AC IN
L
R
:FM
:CD
B
MAIN
SECTION
• Signal Path
• RCH is omitted
IN
W
6
14 VCC
2
+VE
3
–VE
1
+18V
REG
IC702
3
T901
F803
F804
1
-15V
REG
REG
3
3
+5V
REG
1
REG
Q801
IC809
+24V
-24V
-30V
3
+15V
REG
1
IC809
IC801
3
+12V
REG
1
IC451
3
+5V
REG
1
IC450
+15V
+12V
+5V
IC803
-15V
T902
SYSTEM CONTROL/
MODE CONTROL
IC103(2/2)
P RY
A
MAIN
SECTION
8
A
C
MUTE
44
FR
ONT R
Y
47
PR
O
TECT
OR
50
SP OFF
43
CENTER R
Y
45
MIX SUB R
Y
42
SUR R
Y
48
POWER RY
REMOTO
CONTROL
RECEIVER
IC101
26
SIRCS
Q105
RESET
Q101
10
RESET
Q102
X1
12
X2
11
X101
4.19MHz
KEY1
33
FUNCTION
KEY
S102-S111
KEY2
32
FUNCTION
KEY
S115-122
KEY3
31
FUNCTION
KEY
S114, S125-130
MUTING LED
59
MUTING
D116
FUNCTION
RV101
POWER
S151
PO
WER
56
LED DRIVE
Q103,104
T
ONE
60
SURR
61
INDEX
62
DIRECT P
ASS
58
5.1 INPUT
57
Q103,104
D111,135
D115-113
TUNER
64
VIDEO1
70
MD/T
APE
66
PHONO
63
TV/DBS
67
131
D124
CD
65
71 78 . 80 88
100 89
FL101
FL TIBU
F2
F1
P1 17
G1 12
09
39
STOP
I/R
CONT
IC102
I/O
BUFFER
Q106
RESET
Q107
11
14
12
5
33
2
CTRL A1 LA
T
28
15
16
X102
7.28MHz
I/R
DET
IC107
LED
DRIVE
Q129,130
D101-103
VIDEO 3
68
VIDEO 2
69
CTRL A1
REAR
SPEAKER
RE B
54
RE A
53
– 11 –
THIS NOTE IS COMMON FOR PRINTED WIRING
BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed
in each block.)
BOARDS AND SCHEMATIC 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.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
¢
: internal component.
•
2
: nonflammable resistor.
•
C
: panel designation.
•
U
: B+ Line.
•
V
: B– Line.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : FM
no mark : FM
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
• Signal path.
F
: FM
L
: AUDIO
g
: VIDEO
i
: SURROUND
d
: PB (TAPE/MD)
G
: REC (TAPE/MD)
p
: Y
l
: CHROMA
J
: CD
I
: PHONO
For printed wiring boards.
Note:
• X
• 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
These are omitted
E
B
Note:
The components identified by mark
!
or dotted line
with mark
!
are critical for safety.
Replace only with part number specified.
1
2
IC103
!¡
X2
IC102
!§
XOUT
WAVEFORMS
– DISPLAY SECTION –
– DISPLAY SECTION –
7.28MHz
3.8Vp-p
4.19MHz
4.3Vp-p
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