Electrical Adjustments; Tuner Section - Sony CDX-C680 Service Manual

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.
TEST MODE
This set have the test mode function. In the test mode, FM Auto
Scan/Stop Level and AM 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. AM Auto Scan/Stop Level Adjustment

ELECTRICAL ADJUSTMENTS

0 dB = 1 µV
SECTION 3
FM Auto Scan/Stop Level Adjustment
Setting :
SOURCE button : FM
FM RF signal
generator
Carrier frequency : 97.9 MHz
Output level
Mode
Modulation
Procedure :
1. Set to the test mode.
2. Push the SOURCE button and set to FM.
3. Push the preset 3 button.
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.
Adjustment Location : See page 29.
– 27 –
antenna
terminal
0.01 µ F
set
: 22 dB (12.6 µ V)
: mono
: 1 kHz, 22.5 kHz deviation (30%)
Display
1ALL
Display
1ALL
Display
1ALL