Read Sharp XL-HP737 (serv.man4) Service Manual online
XL-HP737
2 – 1
Audio
XL-HP737
Service Manual
XLHP737
Market
E
CHAPTER 2.
ADJUSTMENTS
[1] ADJUSTMENT
1. MECHANISM SECTION
• Driving Force Check
• Torque Check
2. TUNER SECTION
fL: Low-range frequency
fH: High-range frequency
• AM IF/RF
Signal generator: 400 Hz, 30%, AM modulated
• FM RF
Signal generator: 1 kHz, 40 kHz dev., FM modulated
• FM IF
Signal generator: 10.7MHz FM modulated
• Tape Speed
3. CD SECTION
•
Adjustment
Since this CD system incorporates the following automatic adjust-
ment functions, readjustment is not needed when replacing the
pickup. Therefore, different PWBs and pickups can be combined
freely.
ment 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.
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.)
IC.)
*
Focus offset adjustment
*
Tracking offset adjustment
Torque Meter
Specified Value
Play: TW-2111
Over 80 g
Torque Meter
Specified Value
Play: TW-2111
30 to 80 g.cm
Fast forward: TW-2231
70 to 180 g.cm
Rewind: TW-2231
70 to 180 g.cm
Test Stage
Frequency
Frequency
Display
Setting/
Adjusting
Parts
Instrument
Connection
AM IF
450 kHz
1,602 kHz
T351
*1
AM Band
Coverage
Coverage
—
531 kHz
(fL): T306
1.1 ± 0.1 V
1.1 ± 0.1 V
*2
AM Tracking
990 kHz
990 kHz
(fL): T303
*1
*1. Input: Antenna
Output: TP302
*2. Input: Antenna
Output: TP301
Test Stage
Frequency
Frequency
Display
Setting/
Adjusting
Point
Instrument
Connection
FM Band
Coverage
Coverage
—
87.50 kHz
T301 (fL):
1.3 ± 0.1 V
1.3 ± 0.1 V
*1
FM RF
98.00 MHz
(10-30 dB)
(10-30 dB)
98.00 MHz
L312
*2
*1. Input: Antenna
Output: TP301
*2. Input: Antenna
Output: Speaker terminal
Test Stage
Frequency
Frequency
Display
Setting/
Adjusting
Point
Instrument
Connection
IF
10.7 MHz
98 MHz
T302
(Turn the
core of trans-
former T302
fully counter-
clock wise)
(Turn the
core of trans-
former T302
fully counter-
clock wise)
*1
*1. Input: Antenna
Output: TP301
Test Tape
Adjusting
Point
Specified
Value
Instrument
Connection
Normal
speed
speed
MTT-111
Variable
Resistor in
motor.
Resistor in
motor.
3,000 ± 30 Hz
Speaker Ter-
minal (Load
resistance: 6
ohms)
minal (Load
resistance: 6
ohms)
Figure 1
Figure 2 ADJUSTMENT POINTS
TAPE MECHANISM
Tape
Motor
Variable Resistor in motor
AM
LOOP
ANTENNA
IC302
T351
T301
IC303
T303
T306
T302
L312
CNP301
SO302
IC301
TP302
TP301
AM TRACKING fL
AM BAND
COVERAGE fL
AM IF
FM RF
FM IF
FM OSC
FM ANTENNA
TERMINAL
TUNER PWB-C
20
R356
C393
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