CDX-C4840R, CDX-C4850R - Sony Car Audio Service Manual (repair manual). Page 17

View Sony CDX-C4840R / CDX-C4850R Service Manual online

– 17 –
1
 P 2x3
2
 sled motor assy
3
 optical pick-up block
7
 chassis (OP) (O/S) assy
9
 compression spring (FL)
5
 Fit lever (D) in the
     direction of the arrow.
3
 damper (T)
4
 damper (T)
6
 Turn loading ring in the
     direction of the arrow.
1
 tension spring (angle)
8
 compression spring (FL)
2
 tension spring (KR1)
2-11. CHASSIS (OP) (O/S) ASSY
2-12. OPTICAL PICK-UP BLOCK
– 18 –
SHUF
SHUF
SHUF
FM RF signal
generator
0.01 
µ
F
antenna
terminal
set
SECTION 3
ELECTRICAL ADJUSTMENTS
Carrier frequency : 98.00 MHz
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.
Display
FM Auto Scan/Stop Level Adjustment
Setting :
D-BASS switch : OFF
SOURCE button : FM
3. Push the preset  3  button.
Display
  TUNER SECTION
0 dB = 1 
µ
V
Cautions during repair
When the tuner unit is defective, replace it by a new one
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.
<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.
<Release the Test Mode>
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
3. FM RDS S-Meter Adjustment
4. MW Auto Scan/Stop Level Adjustment
4. Adjust with the volume RV2 on TU601 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.
Display
Adjustment Location : See page 20.
– 19 –
SHUF
SHUF
FM RF signal
generator
0.01 
µ
F
antenna
terminal
set
+
FM RF signal
generator
0.01 
µ
F
antenna
terminal
set
LINE OUT REAR
10 k 
level meter
FM Stereo Separation Adjustment
Setting :
D-BASS switch : OFF
SOURCE button : FM
Carrier frequency : 98.00 MHz
Output level
: 70 dB (3.2 mV)
Mode
: stereo
Modulation
: main : 1 kHz, 20 kHz deviation (26.5%)
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 TU601
for nimum reading.
R-CH
R-CH
C
D
L-CH
R-CH
Adjust RV4 on TU601
for minimum reading.
L-CH stereo separation : A – B
R-CH stereo separation : C – D
The separations of both channels should be equal.
Specification : Separation more than 28 dB
Adjustment Location : See page 20.
Procedure :
Carrier frequency : 98.00 MHz
Output level
: 35 dB (56.2 
µ
V)
Mode
: mono
Modulation
: no modulation
Procedure :
1. Set to the test mode. (See page 18.)
2. Push the  SOURCE  button and set to FM.
Display
FM RDS S-Meter Adjustment
Setting :
D-BASS switch : OFF
SOURCE button : FM
3. Push the preset  10  button.
4. Adjust RV801 so that the display indication is “16.0”.
Display
Specification : Display indication : 15.8 to 16.2
Adjustment Location : See page 20.
– 20 –
AM RF signal
generator
AM dummy
antenna (50 
)
set
antenna
terminal
30 
15 pF
65 pF
TU601
RV1
MW AUTO SCAN/
STOP LEVEL ADJ
RV2
FM AUTO SCAN/
STOP LEVEL ADJ
RV801
FM RDS
S-METER ADJ
RV4
FM STEREO
SEPARATION ADJ
(NARROW)
TP
SHUF
TP
SHUF
TP
SHUF
MW Auto Scan/Stop Level Adjustment
Setting :
D-BASS switch
: OFF
SOURCE 
n MODE button : MW
Carrier frequency : 999 kHz
30% amplitude
modulation by
1 kHz signal
output level
: 33 dB (44.7 
µ
V)
Procedure :
1. Set to the test mode. (See page 18.)
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 TU601 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.
Display
Adjustment Location : tuner unit (TU601)
Adjustment Location : tuner unit (TU601)

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