Sony STR-DB795 Service Manual ▷ View online
13
STR-DB795
3-8. MAIN BOARD
9
heatsink block
0
MAIN board
8
twelve screws
(transistor)
(transistor)
2
two connectors
(CN2701, 2703)
(CN2701, 2703)
1
six connectors (CN421, 401, 601, 651, 501, 420)
3
connector (CN951)
5
connector (CN423)
6
connector (CN416)
7
connector (CN409)
4
A CLASS board
14
STR-DB795
TUNER FACTORY PRESET MODE
All preset contents are reset to the default setting.
Procedure:
Procedure:
1. While pressing the [MUSIC] and [PRESET TUNING --] buttons,
press the
I
/1
button to turn on the main power.
2. The message “FACTORY” appears and the present contents
are reset to the default values.
TUNER AM STEP CHANGE (9 kHz/10 kHz) MODE
Either the 9 kHz step or 10 kHz step can be selected for the AM
channel step.
Procedure:
channel step.
Procedure:
1. Press the
I
/1
button to turn on the main power.
2. Turn the [INPUT SELECTOR] dial to select the “AM”
3. Press the
3. Press the
I
/1
button to turn off the main power.
4. While pressing the [PRESET TUNING +] or [TUNING +] button,
press the
I
/1
button to turn on the main power.
5. Either the message “9 K STEP” or “10 K STEP” appears.
Select the desired step.
TUNER AUTOBETICAL TUNING MODE
(AEP and UK models)
(AEP and UK models)
Procedure:
1. While pressing the [MEMORY/ENTER] button, press the
I
/1
button to turn on the main power.
2. The message “AUTO-BETICAL SELECT” appears and scans
and stores all the FM and FM RDS stations in the broadcast
area.
area.
3. When done, the message “FINISH” appears.
SOUND FIELD CLEAR MODE
The preset sound field is cleared when this mode is activated. Use
this mode before returning the product to clients upon completion
of repair.
Procedure:
this mode before returning the product to clients upon completion
of repair.
Procedure:
1. While pressing the [2CH] button, press the
I
/1
button to turn
on the main power.
2. The message “SF. CLR.” appears and initialization is
performed.
FLUORESCENT INDICATOR TUBE PATTERN
CHECK MODE
CHECK MODE
All fluorescent segments are tested. When this test is activated, all
segments turn on at the same time, then each segment turns on one
after another.
Procedure:
segments turn on at the same time, then each segment turns on one
after another.
Procedure:
1. While pressing the [PRESET TUNING --] and [A.F.D.] buttons,
press the
I
/1
button to turn on the main power.
2. All segments and [MULTI CHANNEL DECODING] indicator LED
turn on.
SHIPMENT MODE
All preset contents are cleared when this mode is activated. Use
this mode before returning the product to clients upon completion
of repair.
Procedure:
this mode before returning the product to clients upon completion
of repair.
Procedure:
1. While pressing the [PRESET TUNING --] and [SURR BACK
DECODING] buttons, press the
I
/1
button to turn ton the main
power.
2. The message “CLEARING” appears and memories are reset
to the default values and the main power turn off automatically.
SWAP ALL MODE
Procedure:
1. While pressing the [PRESET TUNING +] and [A.F.D.] buttons,
press the
I
/1
button to turn on the main power.
2. The message “SWAP” appears.
COMMAND MODE CHANGE MODE
The command mode of the remote-commander which this set
receives can be changed.
Procedure:
receives can be changed.
Procedure:
1. While pressing the [INPUT MODE] buttons, press the
I
/1
but-
ton to turn the main power.
2. Either the message “C.MODE.AV1” or “C.MODE.AV2”
appears. Select the desired mode.
VERSION CHECK MODE
The version of the micro computer displayed.
Procedure:
Procedure:
1. While pressing the [PRESET TUNING --] and [2CH] buttons,
press the
I
/1
button to turn the main power.
2. The version of the micro computer and model destination are
displayed.
DECODE AUTO ALL MODE
Procedure:
1. While pressing the [PRESET TUNING --] and [MOVIE] buttons,
press the
I
/1
button to turn the main power.
2. The message “DEC TEST” appears.
PROTECTOR AUTO OFF
When this mode is used, a protector on state is maintainable.
Procedure:
Procedure:
1. While pressing the [PRESET TUNING +] and [MOVIE] buttons,
press the
I
/1
button to turn on the main power.
2. The message “PROT EVER” appears.
SECTION 4
TEST MODE
15
STR-DB795
BIAS ADJUSTMENT
Condition:
input signal: no signal (no load)
volume:
input signal: no signal (no load)
volume:
minimum
Connection
Procedure:
1. Connect a digital voltmeter to the CN432 (CN482, CN532,
CN582, CN632, CN682) on the MAIN board or CN732 on
the SBL board.
the SBL board.
2. Press the
I
/1
button to turn on the main power.
3. Adjust the RV431 (RV481, RV531, RV581, RV631, RV681)
on the MAIN board or RV731 on the SBL board so that the
digital voltmeter reading is 15
digital voltmeter reading is 15
±
2 mV.
Note:
When the adjusting voltage is higher than 15
±
2 mV, adjust the
voltage to the minimum voltage.
Adjustment and Connection Loacation:
+
–
–
digital voltmeter
CN432 (CN482, 532, 582, 632, 682, 732) pin
1
CN432 (CN482, 532, 582, 632, 682, 732) pin
2
RV731
– SBL BOARD (Component Side) –
CN732
1
2
– MAIN BOARD (Component Side) –
RV431
CN432
2 1
RV481
RV631
RV681
RV531
RV581
CN482
CN632
CN682
CN532
CN582
2 1
2 1
2 1
2 1
2 1
SECTION 5
ELECTRICAL ADJUSTMENTS
STR-DB795
17
17
STR-DB795
6-1. BLOCK DIAGRAM – TUNER/VIDEO Section –
SECTION 6
DIAGRAMS
• SIGNAL PATH
: TUNER
A
DATA,
CLK
CLK
FM
AM
8
L CH
10
R CH
13
FM SIG OUT
14
RDS-INT
15
RDS-DATA
116
VIDEO_SW3
117
VIDEO_SW4
115
VIDEO_SW2
114
VIDEO_SW1
100
UP CON SCL
99
UP CON SDA
2
ST-DO
4
CE
3 ST-DI
1 CLK
7
STEREO
11
MUTE
6
TUNED
(AEP, UK)
TU301
TUNER UNIT
47 RDS.DATA
RDS_SIGNAL
RDS_CLK
66 TUNER LATCH
49 TUNER TUNED
48 TUNER ST
50 TUNER MUTE
135
65 TUNER DO
61
SYSTEM CONTROLLER
IC1703 (1/6)
B
TUNER-L
COAXIAL
FM 75
AM
R-CH
: VIDEO
ANTENNA
SW4
SW3
SW2
SW1
7
9
3
5
13
V3
V2. IN
TV
LD
V1. IN
10
4
14
6
2
15
1
SW2
SW3
SW1
SW4
SW5
V1.
OUT
M.
OUT
7
9
3
5
13
V3
V2. IN
TV
LD
V1. IN
10
4
14
6
2
15
1
SW2
SW3
SW1
SW4
SW5
V1.
OUT
M.
OUT
15
13
9
11
3
5
7
1
2
14
10
4
6
D302
D301
D851
D850
J1091 (1/2)
VIDEO 3
INPUT
VIDEO
VIDEO
TV/SAT IN
DVD IN
VIDEO 2 IN
VIDEO 2 OUT
J305
J304
VIDEO
VIDEO
VIDEO
VIDEO 1 IN
VIDEO 1 OUT
J1092
J852 (2/2)
J850 (2/2)
J850 (1/2)
J852 (1/2)
C
Y
C
Y
C
Y
C
Y
C
Y
J302
VIDEO SELECTOR
IC301
Y SWITCH
IC851
C SWITCH
IC850
VIDEO 3
INPUT
S-VIDEO
S-VIDEO
TV/SAT IN
S-VIDEO
DVD IN
S-VIDEO
VIDEO 1 IN
VIDEO
MONITOR OUT
V1. OUT
V1. IN
V2. IN
V2. OUT
TV
LD
V3
M. OUT
SW5
SW1
SW2
SW3
SW4
S-VIDEO
VIDEO 1 OUT
SW4
SW1
SW2
SW3
P
B
/C
B
/B-Y
P
R
/C
R
/R-Y
P
B
/C
B
/B-Y
P
R
/C
R
/R-Y
J351 (1/2)
Y
Y
J351(2/2)
Y
COMPONENT
VIDEO
TV/SAT IN
COMPONENT
VIDEO
DVD IN
P
B
/C
B
/B-Y
P
R
/C
R
/R-Y
COMPONENT
VIDEO
MONITOR OUT
C
Y
J851
S-VIDEO
MONITOR OUT
RY850
-2
-1
VIDEO BUFFER
Q372
19
27
7
15 16
25
VIDEO SYNC
SEPARATOR
SEPARATOR
IC370
4
1
7
16
CLOCK
GENERATOR
IC371
X370
3.5795MHz (Taiwan, Korean models)
4.43MHz (EXCEPT Taiwan, Korean models)
C SYNC BUFFER
Q370
RELAY
DRIVE
Q850, 851
SYNC SEPARATOR
IC852
Y SYNC BUFFER
Q371
RY352
-2
-1
RY354
RELAY
DRIVE
Q352
RY351
-2
-1
RY353
RELAY
DRIVE
Q351
VIDEO AMP
IC372
DATA
CLK
CLK
• R-CH is omitted due to same as L-CH.
(Page 21)
(Page 19)
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