Sony CDX-C780R Service Manual ▷ View online
– 25 –
1
P 2x3
2
sled motor assy
3
optical pick-up block
6
chassis (OP) (O/S) assy
7
compression spring (FL)
4
Fit lever (D) in the
direction of the arrow.
3
damper (T)
2
damper (T)
5
Turn loading ring in the
direction of the arrow.
1
tension spring (angle)
8
compression spring (FL)
2-11. CHASSIS (OP) (O/S) ASSY
2-12. OPTICAL PICK-UP BLOCK
– 26 –
SECTION 3
ELECTRICAL ADJUSTMENTS
Carrier frequency : 98.00 MHz
Output level
Output level
: 22 dB (12.6
µ
V)
Mode
: mono
Modulation
: 1 kHz, 22.5 kHz deviation (30%)
Procedure :
1. Set to the test mode.
2. Push the SOURCE button and set to FM.
1. Set to the test mode.
2. Push the SOURCE button and set to FM.
Display
FM Auto Scan/Stop Level Adjustment
Setting :
SOURCE button : FM
3. Push the preset 3 button.
Display
4. Adjust with the volume RV2 on TU10 so that the “FM”
indication turns to “FM0” indication on the display window.
But, in case of already indicated “FM0”, turn the RV2 so that
put out light “0” indication and adjustment.
But, in case of already indicated “FM0”, turn the RV2 so that
put out light “0” indication and adjustment.
Display
CD SECTION
CD section adjustments are done automatically in this set.
TUNER SECTION
Cautions during repair
When the tuner unit is defective, replace it by a new one
because its internal block is difficult to repair.
because its internal block is difficult to repair.
TEST MODE
This set have the test mode function. In the test mode, FM Auto
Scan/Stop Level and MW Auto Scan/Stop Level adjustments can
be performed easier than it in ordinary procedure.
Scan/Stop Level and MW Auto Scan/Stop Level adjustments can
be performed easier than it in ordinary procedure.
<Set the Test Mode>
1. Set the “OFF” mode.
2. Push the preset 4 button.
3. Push the preset 5 button.
4. Press the preset 1 button for more than two seconds.
5. Then the display indicates all lights, the test mode is set.
1. Set the “OFF” mode.
2. Push the preset 4 button.
3. Push the preset 5 button.
4. Press the preset 1 button for more than two seconds.
5. Then the display indicates all lights, the test mode is set.
<Release the Test Mode>
1. Push the OFF button.
1. Push the OFF button.
Note on Adjustment
The adjustments of tuner section, should be performed according
to the following sequence.
1. FM Auto Scan/Stop Level Adjustment
2. FM Stereo Separation Adjustment (WIDE)
3. FM Stereo Separation Adjustment (NARROW)
4. FM RDS S-Meter Adjustment
5. MW Auto Scan/Stop Level Adjustment
to the following sequence.
1. FM Auto Scan/Stop Level Adjustment
2. FM Stereo Separation Adjustment (WIDE)
3. FM Stereo Separation Adjustment (NARROW)
4. FM RDS S-Meter Adjustment
5. MW Auto Scan/Stop Level Adjustment
0 dB = 1
µ
V
FM RF signal
generator
generator
antenna
terminal
terminal
0.01
µ
F
set
SHUF
REG
SHUF
REG
SHUF
REG
Adjustment Location : See page 29.
– 27 –
FM Stereo Separation Adjustment (WIDE)
Setting :
SOURCE button : FM
Carrier frequency : 98.00 MHz
Output level
Output level
: 70 dB (3.2 mV)
Mode
: stereo
Modulation
: main : 1 kHz, 20 kHz deviation (26.5%)
sub
sub
: 1 kHz, 20 kHz deviation (26.5%)
19 kHz pilot : 7.5 kHz deviation (10%)
FM stereo
Level meter
Level meter
signal generator
connection
reading (dB)
output channel
L-CH
L-CH
A
B
R-CH
L-CH
Adjust RV3 on TU10 for
minimum reading.
minimum reading.
R-CH
R-CH
C
D
L-CH
R-CH
Adjust RV3 on TU10 for
minimum reading.
minimum reading.
L-CH stereo separation : A – B
R-CH stereo separation : C – D
The separations of both channels should be equal.
R-CH stereo separation : C – D
The separations of both channels should be equal.
Specification : Separation more than 24 dB
Adjustment Location : See page 29.
Procedure :
FM RF signal
generator
generator
antenna
terminal
terminal
set
level meter
10 k
Ω
LINE OUT REAR
0.01
µ
F
FM Stereo Separation Adjustment (NARROW)
Setting :
SOURCE button : FM
Carrier frequency : 98.00 MHz
Output level
Output level
: 70 dB (3.2 mV)
Mode
: stereo
Modulation
: main : 1 kHz, 20 kHz deviation (26.5%)
sub
sub
: 1 kHz, 20 kHz deviation (26.5%)
19 kHz pilot : 7.5 kHz deviation (10%)
FM stereo
Level meter
Level meter
signal generator
connection
reading (dB)
output channel
L-CH
L-CH
A
B
R-CH
L-CH
Adjust RV4 on TU10 for
minimum reading.
minimum reading.
R-CH
R-CH
C
D
L-CH
R-CH
Adjust RV4 on TU10 for
minimum reading.
minimum reading.
L-CH stereo separation : A – B
R-CH stereo separation : C – D
The separations of both channels should be equal.
R-CH stereo separation : C – D
The separations of both channels should be equal.
Specification : Separation more than 18 dB
Adjustment Location : See page 29.
Procedure :
1. Set to the test mode.
2. Push the SHIFT button.
3. Push the 4 button three times.
4. Push the 5 button twice and set to NARROW mode.
1. Set to the test mode.
2. Push the SHIFT button.
3. Push the 4 button three times.
4. Push the 5 button twice and set to NARROW mode.
FM RF signal
generator
generator
antenna
terminal
terminal
set
level meter
10 k
Ω
LINE OUT REAR
0.01
µ
F
1. Set to the test mode.
2. Push the SHIFT button.
3. Push the 4 button three times.
4. Push the 5 button once and set to WIDE mode.
2. Push the SHIFT button.
3. Push the 4 button three times.
4. Push the 5 button once and set to WIDE mode.
Ver 1.1
– 28 –
MW Auto Scan/Stop Level Adjustment
Setting :
SOURCE
n MODE button : MW
Procedure :
1. Set to the test mode. (See page 26.)
2. Push the SOURCE button.
3. Push the MODE button and set to MW.
1. Set to the test mode. (See page 26.)
2. Push the SOURCE button.
3. Push the MODE button and set to MW.
Display
4. Push the preset 3 button.
Display
5. Adjust with the volume RV1 on TU10 so that the “MW”
indication turns to “MW0” indication on the display window.
But, in case of already indicated “MW0”, turn the RV1 so that
put out light “0” indication and adjustment.
But, in case of already indicated “MW0”, turn the RV1 so that
put out light “0” indication and adjustment.
Display
Carrier frequency : 999 kHz
30% amplitude
modulation by
1 kHz signal
output level
30% amplitude
modulation by
1 kHz signal
output level
: 33 dB (44.7
µ
V)
Adjustment Location : See page 29.
AM RF signal
generator
generator
antenna
terminal
terminal
AM dummy
antenna(50
antenna(50
Ω
)
30
Ω
65 pF
15 pF
set
TP
SHUF
REG
TP
SHUF
REG
TP
SHUF
REG
Carrier frequency : 98.00 MHz
Output level
Output level
: 35 dB (56.2
µ
V)
Mode
: mono
Modulation
: no modulation
Procedure :
1. Set to the test mode. (See page 26.)
2. Push the SOURCE button and set to FM.
1. Set to the test mode. (See page 26.)
2. Push the SOURCE button and set to FM.
Display
FM RDS S-Meter Adjustment
Setting :
SOURCE button : FM
3. Push the preset 10 button.
4. Adjust RV10 so that the display indication is “13.0”.
4. Adjust RV10 so that the display indication is “13.0”.
Display
Specification : Display indication : 12.8 to 13.2.
Adjustment Location : See page 29.
FM RF signal
generator
generator
antenna
terminal
terminal
0.01
µ
F
set
SHUF
REG
SHUF
REG
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