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