Adjustment; Mechanism Section; Tuner Section; Adjustment Points - Sharp CDC2900 - 3-CD Compact Stereo System Service Manual

MECHANISM SECTION

Driving Force Check
Torque Meter
Play: TW-2412
Torque Check
Torque Meter
Play: TW-2111 30 to 60 g. cm
Fast forward: TW-2231 —
Rewind: TW-2231 —
Tape Speed
Adjusting
Test Tape
Point
Normal MTT-111 Volume in
speed motor.
(MM1)

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
TAPE MECHANISM
MM 1
Motor
Volume in motor
FM BAND
COVERAGE fL

ADJUSTMENT

Specified Value
Tape 1: Over 80 g
Tape 2: Over 80 g
Specified Value
Tape 1
Tape 2
30 to 60 g.cm
60 to 120 g.cm
60 to 120 g.cm
Specified Instrument
Value Connection
3,000 Speaker
30 Hz terminal
(Load
resistance:
8 ohms)
Setting/ Instrument
Adjusting
Connection
Parts
T351 *1
(fL): T333 *2
1.1 0.1 V
(fL): T331 *1
MAIN PWB
L303
T351
AM IF
1
IC303
13 21
R340
VR351
VCO
Figure 13-1 ADJUSTMENT POINTS
FM RF
Signal generator: 1 kHz, 75 kHz dev., FM modulated
Frequency Frequency
Test Stage
Band —
Coverage
RF 98.00 MHz 98.00 MHz L302
(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
Stage
Detection 10.7 MHz
IF 10.7 MHz
VCO Frequency
Frequency Frequency
Display
98.00 MHz 98.00 MHz
(60 dB)
* Adjust for 76 kHz
Notes:
After preparing the test circuit shown in Fig 13-2, 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.
Pin 21 of IC303
Pin 13 of IC303
D
G
S
L301
1
IC301
CNP301
L302
AM LOOP
T301
FM RF ANTENNA
FM IF
T331
AM TRACKING
TP301
fL
T333
AM BAND
COVERAGE fL
T352
FM DET
TP302
– 13 –
CD-C622/C2900
Serring/ Instrument
Display Connection
Adjusting
Point
87.50 MHz L303(fL):
3.4 V 50 mV
Frequency
Adjusting Instrument
Display Parts Connection
98.00 MHz T352 Input: Pin 1 of
IC303
Output: TP302
98.00 MHz T301(Turn Input: Pin 1 of
the core of IC301
transformer Output: TP302
T352 fully
counter-
clookwise.)
Adjusting Instrument
Parts Connection
VR351* Pin 13, Pin 21
and ground
of IC303
200 Hz.
FET : 2SK19 or 2SK54
TO FREQUENCY
COUNTER
10 k
Figure 13-2
*1
*2