Tuner Section - Sharp CD-BK260V Service Manual

CD-BK260V/CD-BK2700V/CD-BK280V

TUNER SECTION

fL: Low-range frequency
fH: High-range frequency
• AM IF/RF
Signal generator: 400 Hz, 30%, AM modulated
Test Stage Frequency
AM IF 450 kHz
AM Band —
Coverage
AM Tracking 990 kHz
*1. Input: Antenna
*2. Input: Antenna
CD SECTION
• Adjustment
Since this CD system incorporates the following automatic
adjustment functions, readjustment is not needed when
replacing the pickup. Therefore, different PWBs and pickups
can be combined freely.
Each time a disc is changed, these adjustments are
performed automatically. Therefore, playback of each disc
can be performed under optimum conditions.
Items adjusted automatically
(1) Offset adjustment (The offset voltage between the head
amplifier output and the VREF reference voltage is
compensated inside the IC.)
* Focus offset adjustment
* Tracking offset adjustment
(2) Tracking balance adjustment (waveform drawing
Fig.14-2 EFBL)
(3) Gain adjustment (The gain is compensated inside the IC
so that the loop gain at the gain crossover frequency will
be 0 dB.)
* Focus gain adjustment
* Tracking gain adjustment
Frequency Setting/
Instrument
Display Adjusting
Connection
Parts
1,602 kHz T351 *1
531 kHz (fL): T306 *2
1.1 ± 0.1 V
990 kHz (fL): T303 *1
Output: TP302
SO302
Output: TP301
FM ANTENNA
TERMINAL
FM BAND
COVERAGE fL
Figure 14-1 ADJUSTMENT POINTS
• FM RF
Signal generator: 1 kHz, 40 kHz dev., FM modulated
Test Stage Frequency Frequency
FM Band —
Coverage
FM RF 98.00 MHz 98.00 MHz
(10-30 dB)
*1. Input: Antenna
*2. Input: Antenna
CNP301
AM LOOP
MAIN PWB
ANTENNA
T303
AM
IC301
TRACKING fL
R316
L312
T302
T306
FM IF
FM RF
T301
AM BAND
COVERAGE fL
T351
AM IF
TP302
CD ERROR CODE DESCRIPTION
Error
[Servo System Error]
0001 Cannot detect Pickup-in SW
0002 DSP access error
[Error during close operation]
Open/Close SW not functioning (Low → High)
0101
Open/Close SW not functioning (High → Low)
0103
[Error during open operation]
Open/Close SW not functioning (Low → High)
0201
Open/Close SW not functioning (High → Low)
0203
[Error during skip operation]
0302 Pickup-in SW is not detected
0306 During Disc 1 search, Open/Close SW or Clamp SW
or Disc SW do not change to low.
Clamp SW not function (Low → High)
0307
Clamp SW not function (High → Low)
0308
Stopped
CH1=500 mV
T
FDO
1
TE
3
EFBL
2
=Filter=
Smoothing : ON
BW : FULL
– 14 –
Setting/
Display Adjusting
87.50 MHz T301(fL):
1.3 V ± 50 mV
L312
Output: TP301
Output: Speaker terminal
TP301
R357
State Code
T
CH2=200 mV CH3=1 V
DC 10:1 DC 10:1 DC 10:1
=Offset= =Record Length=
CH1 : 0.000 V Main : 100K
CH2 : 0.000 V Zoom : 2k
CH3 : 0.00 V
CH4 : 0.00 V
Figure 14-2
Instrument
Connection
Point
*1
*2
1999/04/05 20:26:47
500 ms/div
(500 ms/div)
NORM:20 kS/s
CH2
v/DIV
200 mV
=Trigger=
Mode : SINGLE
Type : EDGE CH1
Delay : 0.0 ns
0.2 µs
Hold off :