SHARP WQ-740, WQ-780 Service Manual
WQ-740W/WQ-780W
SERVICE MANUAL
No. S7862WQ780W//
WQ-740W
WQ-740W
• In the interests of user-safety the set should be restored to its original
condition and only parts identical to those specified should be used.
WQ-780W
DIFFERENCE BETWEEN
WQ-740W AND WQ-780W
WQ-740W WQ-780W
Auto Reverse None Used
WQ-780W
CONTENTS
AC POWER SUPPLY CORD AND PLUG ...........................................................................................................................1
SPECIFICATIONS ...............................................................................................................................................................2
VOLTAGE SELECTION.......................................................................................................................................................2
FITTING OF DIAL POINTER ...............................................................................................................................................2
NAMES OF PARTS .............................................................................................................................................................3
DISASSEMBLY....................................................................................................................................................................4
ADJUSTMENT ..................................................................................................................................................................... 5
NOTES ON SCHEMATIC DIAGRAM ..................................................................................................................................6
VOLTAGE ............................................................................................................................................................................7
TYPES OF TRANSISTOR AND LED...................................................................................................................................7
SCHEMATIC DIAGRAM / WIRING SIDE OF P.W.BOARD.................................................................................................8
PARTS GUIDE / EXPLODED VIEW
Page
AC POWER SUPPLY CORD AND PLUG
9FF24801830210
9FF24801600292 9FF26802125210
SHARP CORPORATION
9FF26802125120
This document has been published to be used
for after sales service only.
The contents are subject to change without notice.
WQ-740W/WQ-780W
FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT, PLEASE REFER
TO THE OPERATION MANUAL.
SPECIFICATIONS
● General
Power source: AC 110-127 V/220-240 V,
50/60 Hz
DC 15 V ["D" size (UM/SUM1, R20 or HP-2) battery × 10]
Power consumption: 20 W
Output power: PMPO; 120 W (60 W + 60 W)
(AC operation)
MPO (Max.); 30 W
(15 W + 15 W)
(AC operation)
RMS; 15 W (7.5 W + 7.5 W)
(DC operation, 10 % T.H.D.)
Speakers: 12 cm (4-3/4") free-edge
speaker × 2
5 cm (2") surround speaker × 2
Input terminal: MIC 1/2; 1 mV/600 ohms
CD/LINE; 350 mV/47 kohms
Output terminal: Headphones; 16-50 ohms
(recommended; 32 ohms)
Dimensions: Width; 630 mm (24-13/16")
Height; 205 mm (8-1/8")
Depth; 215 mm (8-1/2")
Weight: 5.3 kg (11.7 lbs.) without bat-
teries
VOLTAGE SELECTION
● Radio section
Frequency range: FM; 88 - 108 MHz
SW1; 2.3 - 7.3 MHz
SW2; 7.3 - 22 MHz
MW; 526.5 - 1,606.5 kHz
● Tape recorder section
Frequency response: 60 - 12,000 Hz (Normal tape)
Signal/noise ratio: 40 dB (TAPE 1, recording/playback)
55 dB (TAPE 2, playback)
Wow and flutter: 0.15 % (WRMS)
Motor: DC 15 V electric governor
Bias system: AC bias
Erase system: Magnet erase
Specifications for this model are subject to change without
prior notice.
Before operating the unit on mains, check the preset voltage. If the voltage is different from your local voltage, adjust the voltage
as follows: Slide the AC power supply socket to the visible indication of the side of your local voltage.
FITTING OF DIAL POINTER
1. Remove the main PWB. Attach the dial pointer as shown
A
arrow on the front cabinet, putting it into the section
indicated by arrow .
2. Install the main PWB in the front cabinet and secure it with
the four screws.
3. Turn the tuning control knob in the direction indicated by .
Set the dial pointer to point "0", and then make the rest of
the adjustments.
B
C
Dial Pointer (234)
C
B
Dial Drum (231)
Front Cabinet
A
Tuning Control
Knod (233)
Dial Pointer
(234)
"0" Point
Main PWB
Screw (608)
ø3x10mm
– 2 –
Figure 2
WQ-740W
WQ-740W/WQ-780W
NAMES OF PARTS
24
25
26
27
11.
(TAPE 1) Cassette Compartment
12.
(TAPE 1) Record Button:
13.
(TAPE 1) Play Button:
4.
(TAPE 1) Rewind Button:
15.
(TAPE 1) Fast Forward Button:
16.
(TAPE 1) Stop/Eject Button:
17.
(TAPE 1) Pause Button:
8.
(TAPE 2) Play Button:
9.
(TAPE 2) Rewind Button:
(TAPE 2) Fast Forward Button:
10.
11.
(TAPE 2) Stop/Eject Button:
12.
(TAPE 2) Cassette Compartment
13.
Full-Range Speaker
1615
17 18 19 20 21 22 23
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
1
13 14
28
29
30
31
Surround Speaker
Mixing Microphone Sockets
Mixing Microphone Volume Control
Surround On/Off Switch
Surround Mode Select Switch
Function Selector Switch
Surround Mode Indicators
Band Selector Switch
Tuning Control
Fine Tuning Control
Sound Level Meter
Power Indicator
FM Stereo Indicator
7891011
65432
32
33 34 35
36 37 38
12
27.
Built-in Microphone
28.
Dubbing Speed/Built-in
Microphone/FM Mode Switch
29.
Extra Bass Control: X-BASS
30.
Graphic Equalizer Controls
31.
Volume Control
32.
FM/SW Telescopic Rod Aerial
33.
CD/Line Input Sockets
34.
Headphone Socket
35.
Beat Cancel Switch
36.
Battery Compartment
37.
AC Power Input Socket
38.
AC Voltage Selector
WQ-780W
25
26
27
28
11.
(TAPE 1) Cassette Compartment
12.
(TAPE 1) Record Button:
13.
(TAPE 1) Play Button:
4.
(TAPE 1) Rewind Button:
15.
(TAPE 1) Fast Forward Button:
16.
(TAPE 1) Stop/Eject Button:
17.
(TAPE 1) Pause Button:
18.
(TAPE 2) Reverse Mode Switch:
19.
(TAPE 2) Play Button:
10.
(TAPE 2) Fast Wind Buttons:
11.
(TAPE 2) Stop/Eject Button:
12.
(TAPE 2) Direction Switch:
/
16
17 18 19 20 2122 23 24
13.
(TAPE 2) Cassette Compartment
14.
Full-Range Speaker
15.
Surround Speaker
16.
Mixing Microphone Sockets
17.
Mixing Microphone Volume
Control
18.
Surround On/Off Switch
19.
Surround Mode Select Switch
20.
Function Selector Switch
21.
Surround Mode Indicators
22.
Band Selector Switch
23.
Tuning Control
24.
Fine Tuning Control
25.
Sound Level Meter
26.
FM Stereo Indicator
14 15
29
30
31
32
– 3 –
1
789101112
65432
33
34 35 36
37 38 39
27.
Power/(TAPE 2) Play Direction
Indicators
28.
Built-in Microphone
29.
Dubbing Speed/Built-in
Microphone/FM Mode Switch
30.
Extra Bass Control: X-BASS
31.
Graphic Equalizer Controls
32.
Volume Control
33.
FM/SW Telescopic Rod Aerial
34.
CD/Line Input Sockets
35.
Headphone Socket
36.
Beat Cancel Switch
37.
Battery Compartment
38.
AC Power Input Socket
39.
AC Voltage Selector
13
WQ-740W/WQ-780W
Front Cabinet
(D1)x5
ø3x10mm
(E3)x1
ø2x6mm
(E2)x2
ø3x10mm
Graphic
Equalizer PWB
Volume PWB
Lug Wire
(E1)x1
DISASSEMBLY
Caution on Disassembly
Follow the below-mentioned notes when disassembling
the unit and reassembling it, to keep it safe and ensure
excellent performance:
1. Take cassette tape out of the unit.
2. Be sure to remove the power supply plug from the wall
outlet before starting to disassemble the unit and remove
the batteries from the unit.
3. Take off nylon bands or wire holders where they need
to be removed when disassembling the unit. After
servicing the unit, be sure to rearrange the leads where
they were before disassembling.
4. Take sufficient care on static electricity of integrated
circuits and other circuits when servicing.
STEP REMOVAL PROCEDURE FIGURE
1 Front Cabinet/ 1. Battery Compartment Lid. 4-1
Rear Cabinet ................................. (A1)x1
2. Screw ................... (A2)x1
3. Screw ................... (A3)x8
4. Socket .................. (A4)x1
2 Tape mechanism 1. Screw ................... (B1)x2 4-2
2. Socket(B2)x3 WQ-740W
2. Socket(B2)x4 WQ-780W
3. Open the cassette holder.
4. Screw ................... (B3)x6
3 Main PWB 1. Knob.....................(C1)x1 4-2
2. Screw ................... (C2)x4
3. Socket .................. (C3)x5
4 Graphic Equalizer 1. Screw ................... (D1)x5 4-3
PWB
5 Volume PWB 1. Knob..................... (E1)x1 4-3
2. Screw ................... (E2)x2
3. Screw ................... (E3)x1
6 Power PWB 1. Screw................... (F1)x1 4-4
2. Bracket................. (F2)x1
(B1)x1
ø3x20mm
Front Cabinet
(C3)x1
(C2)x4
ø3x10mm
(B2)x1
Main
PWB
Open
Casette Holder
(Left/Right)
(B3)x6
ø3x10mm
(C3)x4
(B2)x2
(B2)x1
WQ-780W Only
Figure 4-2
Open
(B1)x1
ø3x20mm
Tape Mechanism
(C1)x1
(A2)x1
ø2.6x10mm
(A1)x1
(A3)x8
ø3x20mm
Figure 4-1
(A4)x1
Main PWB
Rear
Cabinet
Front
Cabinet
Figure 4-3
Rear Cabinet
(F2)x1
Power
PWB
Pull
(F1)x1
ø3x10mm
Power
Transformer
Figure 4-4
– 4 –
ADJUSTMENT
WQ-740W/WQ-780W
MECHANISM SECTION
• Driving Force Check
Torque Meter
Play: TW-2412 Tape 1: Over 60 g
Specified Value
Tape 2: Over 50 g
• Torque Check (For WQ-740W)
Torque Meter
Play: TW-2111 30 to 60 g.cm 30 to 60 g.cm
Fast forward: TW-2231 55 g.cm more 55 g.cm more
Rewind: TW-2231 55 g.cm more 55 g.cm more
Specified Value
Tape 1 Tape 2
• Torque Check (For WQ-780W)
Torque Meter
Play: TW-2111 30 to 60 g.cm 30 to 60 g.cm
Fast forward: TW-2231 80 to 135 g.cm 55 to 120 g.cm
Rewind: TW-2231 80 to 135 g.cm 55 to 120 g.cm
Specified Value
Tape 1 Tape 2
• Head Azimuth
Test Tape
MTT-114 Headphones Socket
Instrument Connection
(Load resistance: 32 ohms)
* Open the cassette holder, and load the test tape directly into
the mechanism. (Do not load the tape into the cassette
holder.)
• Tape Speed (Normal only)
Test Tape
MTT-111 Tape 1,2:VR501 3,000 ± 60 Hz Headphones
Adjustment
Point
Specified
Value
Instrument
Connection
Socket
(Loadresistance:
32 ohms)
DECK SECTION
• Bias Oscillation
• Beat Cancel Switch: A
Adjustment Point Specified value Instrument
T301 100 kHz ± 4 kHz Pin 1 of CNS108
Connection
TUNER SECTION
fL: Low-range frequency
fH: High-renge frequency
• FM IF/RF
Test Stage
IF T201 Input: FM Antenna
Detection T202 Output:Pin 9 of IC202
Band fL: L202 Input: Antenna
Coverage fH: TC202 Output: Headphone Socket
Tracking fL(88.0 MHz): L201 (Load resistance:
Specified Value/
Adjusting
Point
fH(108 MHz): TC201 32 ohms)
• AM IF/RF
Test Stage
IF T203
MW Band fL: L203
Coverage fH: TC203
MW Tracking fL(600 kHz): L206
SW1 Band fL(2.3 MHz): L204
Coverage fH(7.3 MHz): TC204
SW1 fL(2.6 MHz): L207
Tracking fH(6 MHz): TC209
SW2 Band fL(7.3 MHz): L205
Coverage fH(22 MHz): TC205
SW2 fL(8.5 MHz): L208
Tracking fH(19 MHz): TC210
Specified Value/
Adjusting
Point
fH(1,400 kHz):TC207
• VCO Frequency
Adjustment
Point
VR201 76 kHz ± 200 Hz Pin 13, Pin 21 and ground
Specified value Instrument Connection
Note:
After preparing the test circuit shown in Fig. 5, connect the Pin
13, Pin 21 and ground of the IC202 with the test circuit, and
measure the value.
Instrument
Connection
Instrument
Connection
Input: Antenna
Output: Pin 9 of IC202
Input: Antenna
Output: Headphone Socket
(Load resistance
32 ohms)
of IC202
Specified Value
Beat Cancel A: 100 ± 4 kHz
B: 94 ± 4 kHz
C: 104 ± 4 kHz
Pin 13 of IC202
– 5 –
Pin 21 of IC202
D
G
10 pF
1M ohm
10K ohm
FET: 2SK212
(or Other 2SK Type FET.)
S
0.1 µF
TO FREQUENCY
COUNTER
Figure 5 VCO FREQUENCY TEST CIRCUIT
WQ-740W/WQ-780W
CNS110
T301
BIAS
OSCILLATION
CNS108
1
2
3
4
SW2
TRACKING
FM
TRACKING
FM
DETECTION
fH
fL
VCO
AM IF
VR201
TC210
L208
fH
T203
IC202
2113
fL
19
T202
TC209
FM IF
T201
IC201
L201
TC
201
TC
207
1
L202
TC
202
TC
203
L203
TC204
TC205
L205
L204
fH
FM BAND
COVERAGE
fL
fH
SW1 BAND
COVERAGE
fL
MW BAND
fL
COVERAGE
fL
SW2 BAND
COVERAGE
fH
MW BAND
fH
COVERAGE
MW
TRACKING
SW1
TRACKING
fH
fL
MW
L206
Figure 6 ADJUSTMENT POINTS
NOTES ON SCHEMATIC DIAGRAM
• Resistor:
To differentiate the units of resistors, The symbol as K and
M are used: the symbol K means 1000 ohm and the symbol
M means 1000 kohm and the resistor without any symbol
is an ohm resistor. The resistor designated “Fusible” is a
fuse type resistor.
• Capacitor:
To indicate the unit of capacitor, a symbol P is used: this
symbol P means pico-farad and the unit of the capacitor
without such a symbol is microfarad. As to electrolytic
capacitor, the expression “capacitance/withstand voltage”
is used.
(CH),(RH),(UJ): Temperature compensation
(ML): Mylar type
(S): Styrol type
• The indicated voltage in each section is the one measured
by Digital Multimeter between such a section and the
chassis with no signal given.
• Schematic diagram and Wiring Side of P.W. Board for this
model are subject to change for improvement without prior
notice.
• Parts marked with “ ” ( ) are important for
maintaining the safety of the set. Be sure to replace these
parts with specified ones for maintaining the safety and
performance of the set.
fH
fL
MAIN PWB
SW1
L207
REF. NO. DESCRIPTION
SW201 BAND SELECTOR FM
SW301 BEAT CANCEL C
SW302 RECORD/PLAYBACK PLAYBACK
SW401 SURROUND MODE LIVE
SELECT
SW402 SURROUND ON/OFF OFF
SW403 DUBBING SPEED/ HIGH/FM STEREO
BUILT-IN MICROPHONE/
FM MODE
SW404 FUNCTION SELECTOR TAPE
SW501 TAPE 2 MAIN OFF
SW502 TAPE 1 MAIN OFF
SW503 TAPE 2 PLAY OFF
SW504 TAPE 2 DIRECTION A
(WQ-780W Only)
SW505 VOLTAGE SELECTOR AC220-240V
POSITION
– 6 –
IFR-523 HD
IFR-553 PD
VIEW
FRONT
2SB1370
2SD2061
8050 C
9014 C
9015 C
9012 G
VIEW
FRONT
E B C
VOL TAGE
WQ-740W/WQ-780W
IC103 (AN6884): Sound Level Meter
PIN
RADIO
TAPE PLAY
TAPE REC
123456789
6.13V
6.16V
6V
6V
0V
6V
6V
6V
6V
6V
0V
6V
6V
6V
6V
6V
0V
6V
IC201 (LA1186N): FM Front End
PIN
FM
AM
TAPE
123456789
1V
1.8V
0V
0V
0V
5V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
IC202 (LA1805): IF Amp, & FM MPX.
PIN
FM
AM
TAPE
123456789101112
1.4V
1.4V
5.6V
0.6V
1.5V
0V
1.6V
1.6V
6V
0.6V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
1.4V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
4V
0V
0V
6.5V
6.5V
6.5V
5V
0V
0V
2.3V
2.4V
0V
2.3V
2.4V
0V
TRANSISTOR
Q101
Q102
Q103
Q106
Q107
Q108
Q202
Q203
Q301
Q302
Q303
Q401
Q402
Q501
Q502
Q503
Q504
Q505
Q506
Q507
Q508
Q509
5V
1V
0.5V
1V
0V
0V
RADIO TAPE RECTAPE PLAY
b
0.63V
0.63V
6.52V
0.69V
6.54V
7.37V
0.98V
0.98V
0.27V
0V
1.18V
0V
0V
8.06V
0V
0V
0.7V
0V
14.23V
0.74V
2.57V
0V
c
3.27V
3.35V
7.28V
0.1V
7.3V
13.67V
2.88V
2.85V
0.27V
0.4V
5.53V
0V
0V
13.14V
0V
–
0V
0.7V
14.98V
0.12V
3.82V
0V
7.36V
7.38V
7.98V
0.32V
0.32V
0.5V
7.43V
15V
15.01V
1.93V
e
0V
0V
7.36V
0V
7.38V
7.98V
0.32V
0.32V
0V
0V
0.5V
0V
0V
7.43V
0V
–1.74V
0V
0V
15.01V
0V
1.93V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
0V
e
b
c
e
b
c
0.63V
3.27V
0.63V
3.35V
6.52V
7.28V
0.69V
0V
6.54V
7.3V
7.37V
0.98V
0.98V
0.27V
0V
1.18V
0V
0V
8.06V
0V
0.70V
0V
14.23V
0.74V
2.57V
0V
13.67V
2.88V
2.85V
0.27V
0.4V
5.53V
0V
0V
13.14V
8.8V
0V
0.7V
14.98V
0.12V
3.82V
0V
0.05V
0.5V
15V
–
0V
0V
1.93V
–0.18V
1.18V
0V
0.7V
0.74V
2.57V
6.2V
5.53V
8.8V
0.12V
3.82V
PIN
FM
AM
TAPE
13 14 15 16 17 18 19 20 21 22 23 24
1V
1V
2V
1V
1.8V
1.5V
1.6V
1.8V
1.8V
1.8V
1.8V
1.8V
1.6V
0.6V
0V
0V
0V
0V
0V
0V
0V
IC301 (TA8189N): Record/Playback Amp.
PIN
RADIO
TAPE PLAY
TAPE REC
PIN
RADIO
TAPE PLAY
TAPE REC
123456789101112
0.98V
0.98V
2.11V
1.57V
5.7V
4.8V
0V
0.98V
0.98V
2.11V
1.6V
5.7V
4.8V
0V
0.98V
0.98V
2.11V
1.6V
5.7V
4.8V
0V
13 14 15 16 17 18 19 20 21 22 23 24
1.4V
0V
1.29V
2V
1.4V
5.8V
0V
1.4V
0V
1.29V
2V
1.4V
5.8V
0V
1.4V
0V
1.29V
2V
1.4V
5.8V
0V
IC401 (BA4558): Ope Amp.
PIN
RADIO
TAPE PLAY
TAPE REC
12345678
3.3V
3.3V
3.3V
0V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
0V
3.3V
3.3V
3.3V
3.3V
3.3V
3.3V
0V
3.3V
3.3V
3.3V
IC402 (LA4558): Power Amp.
PIN
RADIO
TAPE PLAY
TAPE REC
12345678910
14.5V
0.01V
1.1V
7.6V
0.6V
13.6V
0V
14.5V
0.01V
1.1V
7.6V
0.6V
13.6V
0V
14.5V
0.01V
1.1V
7.6V
0.6V
13.6V
0V
0.4V
6.6V
0V
0V
0V
0V
5.7V
5.7V
5.7V
6.7V
6.7V
6.7V
15V
15V
15V
5.7V
6.6V
0V
2V
2V
2V
5.3V
5.3V
5.3V
13.7V
13.7V
13.7V
5.7V
1.67V
0V
1.2V
1.2V
1.2V
2V
2V
2V
0.6V
0.6V
0.6V
1.62V
1.67V
0V
0V
0V
0V
1V
1V
1V
1.62V
1.4V
0V
0V
0V
0V
1V
1V
1V
PIN
RADIO
TAPE PLAY
TAPE REC
7.6V
7.6V
7.6V
11 12 13 14
1.1V
0.01V
1.1V
0.01V
1.1V
0.01V
0V
0V
0V
Figure 7 TYPE OF TRANSISTOR AND LED
– 7 –
WQ-740W/WQ-780W
4
L
A
A
0
M
E
E
WQ-740W
FM/SW
A
B
C
RECORD/PLAYBACK
D
L-CH
R-CH
+
ERASE
HEAD
E
PLAYBACK HEAD
L-CH
F
R-CH
J2
G
CD/LINE
H
ROD ANTENNA
TAPE1
HEAD
TAPE2
L-CH
GND
R-CH
CNH108
4 4
CNH107
1 1
2 2
3 3
CNS108
1 1
2 2
3 3
CNS107
R452
47K
R451
47K
SW201
BAND SELECTOR
SW201-B
D202
1N4148
MW
TRACKING
SW201-F
FM
MW
SW1
SW2
VC203
SW201
BAND
SELECTOR
SW201-C
FM
MW
SW1
SW2
TC210
fHSW2
TRACKING
fL
SW302
RECORD/PLAYBACK
SW302-B
PR PR
LA
GA
BA
RA
SW302-E
RPRP
LB
GB
RB
C515
130P
L303
C517
22mH
150P
BEAT CANCEL
ABC
R454
2.2K
R453
2.2K
C357
120P
FM SIGNAL
MW/SW1/SW2 SIGNAL
PLAYBACK SIGNAL
RECORD SIGNAL
FM
MW
SW1
SW2
fL
fH
C516
150P
SW302-C
SW302-D
SW301
C356
430P
1 2 3
FM RF
L201
FM
TRACKING
TC209
L206,L207
MW/SW1 BAR
ANTENNA
C245
12P(CH)
C301
C527
470
R321
12K
C355
1
C201
0.001
CF201
BAND PASS
FILTER
108MHz
C203
22P(CH)
C204
fHfL
0.001
TC207
C243
7P(CH)
C244
5P(CH)
SW1 ANTENNA
C321
130P
L304
22mH
0.001(ML)
C303
0.001
1 2 3 4
C302
0.001(ML)
C304
0.001
AC BIAS CIRCUIT
0.0015(ML)
T301
BIAS
OSCILLATION
IC201
LA1186N
FM FRONT END
2 3 4
C202
0.001
TC201
R201
10
L206
MW
ANTENNA
L207
L208
SW2 ANTENNA
R322
12K
C528
470P
R305
56
C307
0.033(ML)
R311
150K
C305
33/16
C365
330P
C363
330P
C364
330P
C366
330P
C306
33/16
R306
56
0.0056(ML)
0.01(ML)
6
5
FM
OSCILLATION
L202
VC201
R203
C211
0.022
BAND SELECTOR
FM
MW
SW1
SW2
C241
3P(CH)
R220
220
VR202
5K(B)
FINE TUNING
R326
33K
3.9K
R307
4.7K
R309
C309
4.7/50
R303
180K
IC301
TA8189N
RECORD/PLAYBACK AMP.
6
5
3.9K
R310
C310
4.7/50
R304
180K
C308
0.033(ML)
150K
R308
R333
27K
C353
R332
10
C354
8
9
7
C207
3P
C208
R202
C206
20P(CH)
33
TC202
VC202
22K
C210
10/16
SW201
R219
100
SW201-E
fL
SW1
TRACKINGfH
SW201-G
FM
MW
SW1
SW2
VC204
SW2 BAND
COVERAGE
DUBBING CONTROL
R559
100K
Q509
9014 C
C325
47/16
C327
1000/10
C326
R317
2.2/50
180K
8
9
7
R320
C320
4.7/50
C318
10/16
4.7K
R312
R368
10K
R324
C323
22/16
10K
R325
Q301
8050 C
BIAS OSC.
C352
100/16
C351
0.022
33P(CH)
1N4148
C238
360P
TC203
C239
0.0022
TC204
C240
0.0047
TC205
R328
C319
4.7/50
10
180K
18K
SW302-A
R330
100
R205
220K
D203
R204
100
fLfH
100
SW302-F
C212
0.022
fL
FM BAND
COVERAGE
fH
T201
FM IF
MW BAND
COVERAGE
fH fL
C235
10P(CH)
C236
5P(CH)
C237
5P(CH)
L361
2.7mH
R319
2.2K
C361
0.015(ML)
R361
270
C317
10/16
131415161718192021222324
11
12
C316
330P
R362
270
L302
2.7mH
R318
2.2K
C362
0.015(ML)
DUBBING SPEED/
R323
BUILT-IN MICROPHONE/
10K
SW403-B
P
R
P
SW302
RECORD/
PLAYBACK
R
R207
820K
FM DETECTION
C214
0.022
R206
47
L203
MW OSC.
L204
SW1 OSC.
L205
SW2 OSC.
R327
100K
0.0033(ML)
C311
0.0082(ML)
R367
18K
R313
R315
330K
C313
4.7/50
C315
330P
C338
47/16
R364
1M
C314
4.7/50
R314
22K
330K
R316
C312
0.0033(ML)
SW403
FM MODE
HIGH/FM STEREO
NORMAL/FM STEREO
MIC/FM MONO
R513
10K
R336
100
T202
FM IF
CF202
10.7MHz
1 2 3
R222
47
fL
SW1 BAND
COVERAGE
fH
R223
C242
0.022
C520
22K
SW404-C
SW404
FUNCTION
SELECTOR
C259
1/50
C261
1/50
18K
R250
TAPE
CD/LINE
RADIO
0.0082(ML)
C521
R510
10K
R512
10K
Q505
9014 C
TAPE
SPEED
CONTROL
C213
10/16
R208
3.9K
2
1
C231
0.022
C229
0.022
R221
47
SW201-H
BAND SELECTOR
FM
MW
SW1
TAPE
C260
1/50
1/50
Q203 9014 C
LINE AMP.
R241
150K
VR501
470(B)
SW2
CD/LINE
RADIO
Q202
9014 C
LINE AMP.
SW404
R355
18K
CONTROL
MW
SW1
SW2
R240
150K
R245
100
R247
1K
TAPE SPEED
R561
Q503
9015 C
TAPE
SPEED
CONTROL
R508
10K
Q504
9014 C
TAPE
TAPE
SPEED
FM
47
R532
47K
R249
18K
C258
SW404-D
FUNCTION SELECTOR
R533
47K
C218
0.0047(ML)
R209
12K
IC202
LA1805
IF AMP.& FM MPX.
4
3
6
5
C230
22/16
T203
3
1
AM IF
2
CF203
460kHz
AM IF
C228
SW201
1/50
R214
SW201-A
12K
C233
0.022
D521
1N4148
R401
47
R506
3.9K
R354
18K
R246
R243
100
100
1K
C262
1/50
C401
470/16
C263
1/50
R560
56K
R562
2.7K
R216
R563
C219
7
2.2K
D201
2.7K
R403
10K
C220
470P
0.0082(ML)
C221
3.3/50
8
9
C226
C227
1/50
R215
2.2K
1N4148
OPE AMP.
10K
R404
R407
2.7K
OPE AMP.
C512
0.1
C222
3.3/50
15 14 1318 17 1621 20 1924 23 22
10 11 12
C225
0.012(ML)
0.012(ML)
R213
12K
IC401
BA4558
R408
2.7K
C408
0.0033(ML)
C409
0.0033(ML)
IC401
BA4558
C404
10/16
REGULATOR
C511
220/16
C224
1/50
R212
10
SW201-D
FM
MW
SW1
SW2
R218
C534
4.7/50
D516
1N4148
R406
330
8
3
+
(1/2)
2
–
R412
12K
R410
R405
12K
10K
C410
4.7/50
C411
4.7/50
R413
10K
R409
12K
R411
12K
6
–
(2/2)
+
5
4
IC502
KA7809
VOLTAGE
1
2
R210
150K
100
1
C416
220/16
3
7
MIC/FM
NORMAL/FM ST
HIGH/FM ST
R211
15K
VR201
10K(B)
VCO
C232
220/16
C256
0.022
D527
1N4148
C412
1/50
C415
100/16
C413
1/50
L501
47µH
C529
0.022
CD/
R
T
• NOTES ON SCHEMATIC DIAGRAM can be found on page 6.
1
2
34 5
Figure 8 SCHEMATIC DIAGRAM (1/6)
– 8 –
6
WQ-740W/WQ-780W
6
2
L
SW403
DUBBING SPEED/
BUILT-IN MICROPHONE/
FM MODE
IC/FM MONO
/FM STEREO
/FM STEREO
C529
0.022
8
0.0015
CD/LINE
RADIO
TAPE
C223
C530
4.7/50
R416
R415
C407
10/16
R217
10K
SW403-A
330
D526
1N4148
SW404-A
SW404
FUNCTION
SELECTOR
D515
1N4148
10K
C414
0.0033(ML)
C417
0.0033(ML)
D520
R345
1N4148
1K
R341
10K
Q302
9014 C
MUTE
R531
1K
C347
10/16
HALL
2
3
14
12
13 11
D401
1N4001
SWITCHING
Q507 9014 C
CNS110
1
2
CNS102
5
4
3
2
1
1
2
3
4
5
6
1 1
3 3
5 5
6 6
7 7
8 8
9 9
R552
4.7K
R555
4.7K
R553
680
R349
2.2K
LIVE
5
1
220/16
C459
2.2/50(N.P)
IC402
LA4508
C469
10
8
SW401
SURROUND
MODE SELECT
SW401-A
LIVE
C428
0.01(ML)
4
6
C430
100/16
7
C429
100/16
9
POWER AMP.
C437
470/25
POWER PWB-C
C504
0.1
CNH110
1
2
0.1
C503
5
5
4
3
2
1
1
CNH102
FROM GRAPHIC EQUALIZER PWB
CN205
P12 1-C
SW502
TAPE1 MAIN
2 2
SW501
TAPE2 MAIN
4 4
SW503
TAPE2 PLAY
+
–
B
M
TAPE MOTOR
A
1010
CNS1
R554
680
HALL
C427
0.01(ML)
C502
0.1
D504
C501
0.1
D503
D501~D504'RL202DC
C471
820P
M501
C346
4.7/50
C434
1000/10
C432
0.18(ML)
C431
0.18(ML)
C433
1000/10
VR401-B
50K(B)
VOLUME
F501
T2A L250V
D501
D502
R471
8.2K
R534
4.7K
C450
2.2/50(N.P)
TRANSFORMER
BATTERYS
DC15V['' D '' SIZE(UM/SUM-1,
R20 OR HP-2)BATTERYx10]
C473
R472
0.068
8.2K
C472
0.068
CNS109 CNH109
TWL
L-CH
GND
GND
R-CH
TWR
R422
120
R423
120
T501
POWER
AC220-240V
50/60Hz
AC110-127V
50/60Hz
C474
820P
VR401-A
50K(B)
VOLUME
VOLUME PWB-B1
1 1
2 2
1
2
3
4
5
6
7
CN4
CNS106
1
2
3
4
5
6
MIC2
MIC1
EQUALIZER PWB
CNH106
1
2
3
4
5
6
HEADPHONES
SW505
VOLTAGE
SELECTOR
MICROPHONES
MIC101
BUILT-IN
MICROPHONE
FROM GRAPHIC
CN207
P12 1-F
J1
INLET SOCKET
SP4
SURROUND
L-CH SPEAKERS
SP2
FULL-RANGE
SP1
FULL-RANGE
R-CH SPEAKERS
SP3
SURROUND
SO501
AC POWER
AC110-127V/
220-240V
50/60Hz
R566
100K
R440
D305
C342
470/16
27K
1N4148
R564
22K
C440
R567
22K
10/16
D525
D524
C535
4.7/50
C533
4.7/50
VR301
50K(B)
MIC
VOLUME
1N4148
1N4148
D523
1N4148
9014 C
MUTE
0.1
C508
Q510
R557
1K
Q508
9014 C
MIC AMP.
R558
33
R351
SW402
SURROUND
ON/OFF
D402
1N4148
C507
C505
10/16
100/16
C537
10/16
R568
1K
R565
5.6K
R556
150K
C532
500P
1K
SW401
SURROUND
MODE SELECT
SW402-B
ON
OFF
D517
1N4148
FUSE
RESISTOR
REGULATOR
R548
R502
SW404-B
SW401-C
Q501
8050 C
VOLTAGE
100
D522
1N4148
680
D505
R344
4.7K
C341
4.7/50
C536
47/16
LIVE
R421
10K
R442
10K
R441
10K
R420
10K
4.7
R501
RADIO
CD/LINE
FUNCTION
SELECTOR
R343
330
R350
3.9K
HALL
D518
FUSIBLE
D509
TAPE
SW404
Q303
9014 C
MIC AMP.
C343
500P
R450
4.7K
D519
1N4001
Q402
9014 C
POWER MUTE
Q401
9014 C
POWER MUTE
1N4148
Q506
2SB1370
SWITCHING
R545
22K
1N4001
C522
3300/25
D507
1N4001
R346
C344
470K
4.7/50
0.0047(ML)
SW402
SURROUND ON/OFF
SW402-A
ON
OFF
SW401
SURROUND
MODE SELECT
SW401-D
HALL
LIVE
C424
C422
0.0015(ML)
1/50
C426
100/16
C425
100/16
C421
C423
1/50
0.0015(ML)
F1
T1.25A
L250V
R535
330/1W
R537
10K
R419
3.3K
R418
3.3K
VCC
GND
LO0
RO0
CNS101
CNS105
C345
SW401-B
RI0
LI0
MAIN PWB-A
78 9101112
Figure 9 SCHEMATIC DIAGRAM (2/6)
– 9 –
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