Tuner Section - Sharp CD-C662 Service Manual

TUNER SECTION

fL: Low-range frequency
fH: High-renge frequency
• AM IF/RF
Signal generator: 400 Hz, 30%, AM modulated
Test Stage Frequency Frequency
Display
IF 450 kHz 1,720 kHz
Band — 530 kHz
Coverage
Tracking 990 kHz 990 kHz
*1. Input: Antenna, Output: TP302
*2. Input: Antenna, Output: TP301
• FM RF
Signal generator: 1 kHz, 75 kHz dev., FM modulated
Test Stage Frequency Frequency
Display
Band — 87.50 MHz
Coverage
RF 98.00 MHz 98.00 MHz
(10-30 dB)
*1. Input: Antenna, Output: TP301
*2. Input: Antenna, Output: Speaker terminal
• Detection
Signal generator: 10.7 MHz, FM sweep generator
Test Frequency Frequency
Stage Display
Detection 10.7 MHz 98.00 MHz
IF 10.7 MHz 98.00 MHz
FM BAND
COVERAGE fL
Setting/
Instrument
Adjusting
Connection
Parts
T351 *1
(fL): T333 *2
1.1 ± 0.1 V
(fL): T331 *1
Serring/ Instrument
Adjusting Connection
Point
L303(fL): *1
3.4 V ± 50 mV
L302 *2
Adjusting Instrument
Parts Connection
T352 Input: Pin 1 of
IC303
Output: TP302
T301(Turn Input: Pin 1 of
the core of IC301
transformer Output: TP302
T352 fully
counter-
clookwise.)
MAIN PWB
IC301
L303
T301
FM IF
R381
T351
AM IF
TP301
1
T333
IC303
13 21
VR351
VCO R360
Figure 11-1 ADJUSTMENT POINTS
– 11 –
• VCO Frequency
Frequency Frequency
Display
98.00 MHz 98.00 MHz
(60 dB)
* Adjust for 76 kHz ± 200 Hz.
Notes:
After preparing the test circuit shown in Fig 11-2, connect the
Pin 13 , Pin 21 and ground of the IC303 with test circuit, and
measure the Value.
At this time, apply a standard unmodulated signal input and
adjust the VCO.
CD ERROR CODE DESCRIPTION
When a malfunction occurs during CD operation, an error
code will be displayed to identify the function in CD operation
which failed.
Error
0001
0101
0105
0201
0203
0304
0305
0307
Pin 13 of IC303 Pin 21 of IC303
D
G
S
BF301
1
L302
FM RF
T331
T352
FM DET
TP302
CD-C662
Adjusting Instrument
Parts Connection
VR351* Pin 13, Pin 21
and ground
of IC303
State Code
Cannot detect pickup in SW
Tray close operation error
Tray close operation error
Tray open operation error
Tray open operation error
Disc skip operation error
Disc skip operation error
Disc skip operation error
FET : 2SK19 or 2SK54
TO FREQUENCY
COUNTER
10 kΩ
Figure 11-2
AM LOOP
ANTENNA
AM TRACKING
fL
AM BAND
COVERAGE fL