SHARP WQ-740, WQ-780 Service Manual

WQ-740W/WQ-780W

SERVICE MANUAL

No. S7862WQ780W//

WQ-740W

WQ-740W WQ-780W

• 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.
DIFFERENCE BETWEEN
WQ-740W AND WQ-780W
	WQ-740W	WQ-780W
Auto Reverse	None	Used
WQ-780W
CONTENTS
		Page
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
AC POWER SUPPLY CORD AND PLUG
9FF24801830210	9FF26802125120

9FF24801600292						9FF26802125210

This document has been published to be used SHARP CORPORATION 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/SUM-
Power consumption:	1, R20 or HP-2) battery × 10]
	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)
Speakers:	(DC operation, 10 % T.H.D.)
	12 cm (4-3/4") free-edge
	speaker × 2
Input terminal:	5 cm (2") surround speaker × 2
	MIC 1/2; 1 mV/600 ohms
Output terminal:	CD/LINE; 350 mV/47 kohms
	Headphones; 16-50 ohms
Dimensions:	(recommended; 32 ohms)
	Width; 630 mm (24-13/16")
	Height; 205 mm (8-1/8")
Weight:	Depth; 215 mm (8-1/2")
	5.3 kg (11.7 lbs.) without bat-
	teries

● 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)
Wow and flutter:	55	dB (TAPE 2, playback)
	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.

VOLTAGE SELECTION

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 arrow A on the front cabinet, putting it into the section indicated by arrow B .

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 C . Set the dial pointer to point "0", and then make the rest of the adjustments.

Dial Pointer

(234)

Front Cabinet

Dial Pointer (234)

"0" Point

A

	Tuning Control
C	Knod (233)

B

	Screw (608)
Dial Drum (231)	ø3x10mm
	Main PWB
	Figure 2

– 2 –

																			WQ-740W/WQ-780W
WQ-740W				NAMES OF PARTS
							1												12
					13	14		2	3	4	5	6		7	8		9 10 11
		15 16 17 18 19 20 21 22 23									32 33				34		35
						28
						29
		24				30
		25				31
		26												36				37	38
		27
1. (TAPE 1) Cassette Compartment				14.	Surround Speaker												27.	Built-in Microphone
2. (TAPE 1) Record Button:				15.	Mixing Microphone Sockets												28.	Dubbing Speed/Built-in
3. (TAPE 1) Play Button:				16.	Mixing Microphone Volume Control												29.	Microphone/FM Mode Switch
4. (TAPE 1) Rewind Button:				17.	Surround On/Off Switch													Extra Bass Control: X-BASS
5. (TAPE 1) Fast Forward Button:				18.	Surround Mode Select Switch												30.	Graphic Equalizer Controls
6. (TAPE 1) Stop/Eject Button:				19.	Function Selector Switch												31.	Volume Control
7. (TAPE 1) Pause Button:				20.	Surround Mode Indicators												32.	FM/SW Telescopic Rod Aerial
8. (TAPE 2) Play Button:				21.	Band Selector Switch												33.	CD/Line Input Sockets
9. (TAPE 2) Rewind Button:				22.	Tuning Control												34.	Headphone Socket
10. (TAPE 2) Fast Forward Button:				23.	Fine Tuning Control												35.	Beat Cancel Switch
11. (TAPE 2) Stop/Eject Button:				24.	Sound Level Meter												36.	Battery Compartment
12. (TAPE 2) Cassette Compartment				25.	Power Indicator												37.	AC Power Input Socket
13. Full-Range Speaker				26.	FM Stereo Indicator												38.	AC Voltage Selector
WQ-780W
							1												13
					14	15	2 3			4	5	6		7	8		9 10 11 12
		16 17 18 19 20 21 22 23				24
						29				33 34					35	36
						30
		25				31
		26				32
		27
		28											37				38		39
1.	(TAPE 1)	Cassette Compartment	13.	(TAPE 2) Cassette Compartment							27.		Power/(TAPE 2) Play Direction
2.	(TAPE 1)	Record Button:	14.	Full-Range Speaker							28.		Indicators
3.	(TAPE 1)	Play Button:	15.	Surround Speaker									Built-in Microphone
4.	(TAPE 1)	Rewind Button:	16.	Mixing Microphone Sockets							29.		Dubbing Speed/Built-in
5.	(TAPE 1)	Fast Forward Button:	17.	Mixing Microphone Volume							30.		Microphone/FM Mode Switch
				Control									Extra Bass Control: X-BASS
6.	(TAPE 1)	Stop/Eject Button:	18.	Surround On/Off Switch							31.		Graphic Equalizer Controls
7.	(TAPE 1)	Pause Button:	19.	Surround Mode Select Switch							32.		Volume Control
8.	(TAPE 2)	Reverse Mode Switch:	20.	Function Selector Switch							33.		FM/SW Telescopic Rod Aerial
9.			21.	Surround Mode Indicators							34.		CD/Line Input Sockets
	(TAPE 2)	Play Button:	22.	Band Selector Switch							35.		Headphone Socket
10.	(TAPE 2)	Fast Wind Buttons:	23.	Tuning Control							36.		Beat Cancel Switch
11.		/	24.	Fine Tuning Control							37.		Battery Compartment
	(TAPE 2)	Stop/Eject Button:	25.	Sound Level Meter							38.		AC Power Input Socket
12.	(TAPE 2)	Direction Switch:	26.	FM Stereo Indicator							39.		AC Voltage Selector

– 3 –

WQ-740W/WQ-780W

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

(A4)x1

Main PWB Front

Cabinet

(A2)x1 ø2.6x10mm

		Rear
	(A1)x1	Cabinet
		(A3)x8
		ø3x20mm

Figure 4-1

Open

Casette Holder (Left/Right)

Open

(B1)x1

ø3x20mm

Front Cabinet	(B1)x1
(B3)x6
ø3x10mm	ø3x20mm
	Tape Mechanism
	(C1)x1
(C3)x4

	(B2)x1
(C3)x1		(B2)x2
(C2)x4		Main
ø3x10mmPWB (B2)x1
		WQ-780W Only
		Figure 4-2

Graphic

Equalizer PWB

Front Cabinet

Volume PWB

(E1)x1

(D1)x5 ø3x10mm

	(E2)x2
	ø3x10mm
	(E3)x1	Lug Wire
	ø2x6mm
		Figure 4-3

Rear Cabinet

(F2)x1

Power

PWB

Pull

(F1)x1

ø3x10mm

Power

Transformer

Figure 4-4

– 4 –

WQ-740W/WQ-780W

ADJUSTMENT

MECHANISM SECTION

• Driving Force Check

Torque Meter	Specified Value
Play: TW-2412	Tape 1: Over 60 g
	Tape 2: Over 50 g

• Torque Check (For WQ-740W)

Torque Meter	Specified Value
	Tape 1	Tape 2
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

• Torque Check (For WQ-780W)

Torque Meter	Specified Value
	Tape 1	Tape 2
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

• Head Azimuth

Test Tape	Instrument Connection
MTT-114	Headphones Socket
	(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	Adjustment	Specified	Instrument
	Point	Value	Connection
MTT-111	Tape 1,2:VR501	3,000 ± 60 Hz	Headphones
			Socket
			(Loadresistance:
			32 ohms)

DECK SECTION

•Bias Oscillation

•Beat Cancel Switch: A

Adjustment Point	Specified value	Instrument
		Connection
T301	100 kHz ± 4 kHz	Pin 1 of CNS108

TUNER SECTION

fL: Low-range frequency fH: High-renge frequency

• FM IF/RF

	Test Stage	Specified Value/	Instrument
		Adjusting
			Connection
		Point
	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:
		fH(108 MHz): TC201	32 ohms)

• AM IF/RF

	Test Stage	Specified Value/	Instrument
		Adjusting
			Connection
		Point
	IF	T203	Input: Antenna
			Output: Pin 9 of IC202
	MW Band	fL: L203	Input: Antenna
	Coverage	fH: TC203	Output: Headphone Socket
			(Load resistance
	MW Tracking	fL(600 kHz): L206
		fH(1,400 kHz):TC207	32 ohms)
	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

• VCO Frequency

Adjustment	Specified value	Instrument Connection
Point
VR201	76 kHz ± 200 Hz	Pin 13, Pin 21 and ground
		of IC202

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.

Pin 13 of IC202

Pin 21 of IC202

Specified Value

D

Beat Cancel

A: 100 ± 4 kHz

B: 94 ± 4 kHz

G

FET: 2SK212

C: 104 ± 4 kHz

(or Other 2SK Type FET.)

10 pF

S

1M ohm

TO FREQUENCY

0.1 F

10K ohm

COUNTER

Figure 5 VCO FREQUENCY TEST CIRCUIT

– 5 –

WQ-740W/WQ-780W

CNS110

T301

BIAS

OSCILLATION

				FM IF
	FM		fL	T201
	TRACKING		fH
CNS108			T203		1
1	AM IF			IC201
				L201
2					L202
3		9		1
4					TC
		IC202		TC		TC204
	VCO			201	202
		13	21	T202 TC
FM		VR201		207	TC
DETECTION					203	TC205
		TC210
SW2	fH			TC209
TRACKING	fL
	L208

	fH	FM BAND
	fL	COVERAGE
	fH	SW1 BAND
	fL	COVERAGE
L203	fL	MW BAND
		COVERAGE
L204
	fL	SW2 BAND
L205	fH	COVERAGE
	fH	MW BAND
		COVERAGE

		MW	fH
		TRACKING	fL	MAIN PWB
SW1	fH	MW		SW1
TRACKING	fL	L206		L207

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.

REF. NO.	DESCRIPTION	POSITION
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

– 6 –

WQ-740W/WQ-780W

VOLTAGE

IC103 (AN6884): Sound Level Meter

PIN	1	2	3	4	5	6	7	8	9
RADIO	6.13V	6.16V	6V	6V	0V	6V	0V	0V	6.5V
TAPE PLAY	6V	6V	6V	6V	0V	6V	0V	0V	6.5V
TAPE REC	6V	6V	6V	6V	0V	6V	0V	0V	6.5V

IC201 (LA1186N): FM Front End

PIN	1	2	3	4	5	6	7	8	9
FM	1V	1.8V	0V	0V	0V	5V	1.4V	4V	5V
AM	0V	0V	0V	0V	0V	0V	0V	0V	0V
TAPE	0V	0V	0V	0V	0V	0V	0V	0V	0V

IC202 (LA1805): IF Amp, & FM MPX.

TRANSISTOR		RADIO		TAPE PLAY			TAPE REC
	e	b	c	e	b	c	e	b	c
Q101	0V	0.63V	3.27V	0V	0.63V	3.27V
Q102	0V	0.63V	3.35V	0V	0.63V	3.35V
Q103	7.36V	6.52V	7.28V	7.36V	6.52V	7.28V
Q106	0V	0.69V	0.1V	0V	0.69V	0V
Q107	7.38V	6.54V	7.3V	7.38V	6.54V	7.3V
Q108	7.98V	7.37V	13.67V	7.98V	7.37V	13.67V
Q202	0.32V	0.98V	2.88V	0.32V	0.98V	2.88V
Q203	0.32V	0.98V	2.85V	0.32V	0.98V	2.85V
Q301	0V	0.27V	0.27V	0V	0.27V	0.27V	0.05V	–0.18V	6.2V
Q302	0V	0V	0.4V	0V	0V	0.4V
Q303	0.5V	1.18V	5.53V	0.5V	1.18V	5.53V	0.5V	1.18V	5.53V
Q401	0V	0V	0V	0V	0V	0V
Q402	0V	0V	0V	0V	0V	0V
Q501	7.43V	8.06V	13.14V	7.43V	8.06V	13.14V
Q502	0V	0V	0V	15V	0V	8.8V	15V	0V	8.8V
Q503	–1.74V	0V	–
Q504	0V	0.7V	0V	0V	0.70V	0V	–
Q505	0V	0V	0.7V	0V	0V	0.7V	0V	0.7V
Q506	15.01V	14.23V	14.98V	15.01V	14.23V	14.98V
Q507	0V	0.74V	0.12V	0V	0.74V	0.12V	0V	0.74V	0.12V
Q508	1.93V	2.57V	3.82V	1.93V	2.57V	3.82V	1.93V	2.57V	3.82V
Q509	0V	0V	0V	0V	0V	0V

PIN

1

2

3

4

5

6

7

8

9

10

11

12

FM

1.4V

1.4V

5.6V

0.6V

1.5V

0V

0V

0V

2.3V

2.3V

5V

1V

AM

1.6V

1.6V

6V

0.6V

0V

0V

0V

0V

2.4V

2.4V

0.5V

1V

TAPE

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

PIN

13

14

15

16

17

18

19

20

21

22

23

24

FM

1V

1V

2V

1V

1.8V

1.5V

1.6V

0.4V

5.7V

5.7V

1.62V

1.62V

AM

1.8V

1.8V

1.8V

1.8V

1.8V

1.6V

0.6V

6.6V

6.6V

1.67V

1.67V

1.4V

TAPE

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

0V

IC301 (TA8189N): Record/Playback Amp.

PIN

1

2

3

4

5

6

7

8

9

10

11

12

RADIO

0.98V

0.98V

2.11V

1.57V

5.7V

4.8V

0V

0V

2V

1.2V

0V

0V

TAPE PLAY

0.98V

0.98V

2.11V

1.6V

5.7V

4.8V

0V

0V

2V

1.2V

0V

0V

TAPE REC

0.98V

0.98V

2.11V

1.6V

5.7V

4.8V

0V

0V

2V

1.2V

0V

0V

PIN

13

14

15

16

17

18

19

20

21

22

23

24

RADIO

1.4V

0V

1.29V

2V

1.4V

5.8V

0V

5.7V

5.3V

2V

1V

1V

TAPE PLAY

1.4V

0V

1.29V

2V

1.4V

5.8V

0V

5.7V

5.3V

2V

1V

1V

TAPE REC

1.4V

0V

1.29V

2V

1.4V

5.8V

0V

5.7V

5.3V

2V

1V

1V

IC401 (BA4558): Ope Amp.

PIN	1	2	3	4	5	6	7	8
RADIO	3.3V	3.3V	3.3V	0V	3.3V	3.3V	3.3V	6.7V
TAPE PLAY	3.3V	3.3V	3.3V	0V	3.3V	3.3V	3.3V	6.7V
TAPE REC	3.3V	3.3V	3.3V	0V	3.3V	3.3V	3.3V	6.7V

IC402 (LA4558): Power Amp.

FRONT

VIEW

PIN

1

2

3

4

5

6

7

8

9

10

RADIO

14.5V

0.01V

1.1V

7.6V

0.6V

13.6V

0V

15V

13.7V

0.6V

TAPE PLAY

14.5V

0.01V

1.1V

7.6V

0.6V

13.6V

0V

15V

13.7V

0.6V

TAPE REC

14.5V

0.01V

1.1V

7.6V

0.6V

13.6V

0V

15V

13.7V

0.6V

PIN

11

12

13

14

RADIO

7.6V

1.1V

0.01V

0V

E B C

TAPE PLAY

7.6V

1.1V

0.01V

0V

TAPE REC

7.6V

1.1V

0.01V

0V

2SB1370	FRONT
2SD2061	VIEW
8050 C
9014 C	IFR-523 HD
9015 C
9012 G	IFR-553 PD

Figure 7 TYPE OF TRANSISTOR AND LED

– 7 –

WQ-740W/WQ-780W

WQ-740W

R207

IC201

820K

C220

LA1186N

C212

C218

470P

T202

FM/SW

FM FRONT END

0.022

0.0047(ML)

0.0082(ML)

R210

33

10/16

IC202

3.3/50

C202 0.001

FM OSCILLATION

C206 20P(CH)

A

ROD ANTENNA

SW201

R205

R208

12K

C219

C222

150K

MIC/FM M

BAND SELECTOR

C201

1

2

3

4

5

6

7

8

9

220K

3.9K

C221

NORMAL/FM STE

FM

0.001

SW201-B

MW

C207

33P(CH)

HIGH/FM STE

1N4148

SW2

FILTER

C208

C214

R211

SW1

1

3

CF201

3P

D202

BAND PASS

108MHz

0.022

C213

24

23

22

21

20

19

18

17

16

15

14

13

15K

2

R202

FM RF

fL

FM BAND

LA1805

VR201

22P(CH)

TC201

VC201

L202

TC202

VC202

fH

COVERAGE

1

2

3

4

5

9

10

11

12

10K(B)

0

D203

6

7

8

L201

C203

FM IF

IF AMP.& FM MPX.

VCO

1N4148

R206

CF202

47

10.7MHz

C230 22/16

R203

1

3

22K

C231

fL

fH

C204

R201

T201

0.022

0.001

C211

R204

FM

10

C210

2

T203

TRACKING

0.022

10/16

100

FM IF

B

MW

fL

L206

SW201

1

3

C224

TRACKING fH

TC207

BAND SELECTOR

FM

R219

1/50

C529

SW201-F

MW

460kHz

C226 0.012(ML)

C225 0.012(ML)

C243

MW

100

AM IF

0.022

7P(CH)

SW1

2

R212

SW2

SW201-E

CF203

10

FM

ANTENNA

MW BAND

AM IF

MW

fL

SW1

COVERAGE

C232

SW1

fH

TRACKING

fH

fL

VC203

SW2

L207

220/16

C229

C238

0.022

SELECTOR

TC209

C244 5P(CH)

C235

L203

SW201-D

C256

360P

10P(CH)

MW

SW201

FM

BAND

R221

0.022

TC203

SW1

SW201-G

47

C228

C227

SW201

SW201-C

L206,L207

SW1 ANTENNA

C241

FM

MW OSC.

SW201-H

1/50

1/50

SW2

FM

C239

C236

BAND SELECTOR

R218

MW/SW1 BAR

3P(CH)

MW

L204

FM

R214

R213

D527

MW

ANTENNA

SW2

0.0022

5P(CH)

R222FMMW

SW1 SW2

SW201-A

100

RA

SW2

L208

SW1

12K

12K

1N4148

SW1

SW1

MW

CD/L

C

R220

TC204

47

SW2

T

220

C233

R216 2.2K

R215

C534

TC210

VC204

C240

SW1 OSC.

fL

SW1 BAND

0.022

2.2K

4.7/50

C245

0.0047

fH

COVERAGE

12P(CH)

TC205

R223

D516

SW2

fH

SW2 ANTENNA

VR202

C237

47

1N4148

TRACKING

fL

C242

L205

5K(B)

fH

fL

5P(CH)

0.022

FINE TUNING

SW2 OSC.

SW2 BAND

COVERAGE

R327

100K

C516

C321

R322

D521

150P

130P

12K

DUBBING CONTROL

1N4148

C528

R559

SW302

L304

100K

RECORD/PLAYBACK

22mH

470P

Q509

SW302-B

SW302-C

C520

TAPE1

9014 C

0.0033(ML)

D

RECORD/PLAYBACK

P

R

P

R

HEAD

CNH108

CNS108

L361

C311

R532

C301

0.001(ML)

R307 3.9K

R309 4.7K

C325 47/16

C327 1000/10

C319 4.7/50

100

CD/LINE

D201 1N4148

270

R367

R354

L-CH

R305

R326

2.7mH

0.0082(ML)

47K

33K

56

R328

R319 2.2K

TAPE RADIO

1

1

LA

C307

18K

18K

100

R-CH

2

2

GA

0.033(ML)

3

3

BA

R311

C361

0.015(ML)

R313

1/50

R240

R246

R406

SELECTOR

C262

4

4

RA

150K

R315

22K

SW404-C

1K

330

SW404

330K

FUNCTION C260

C303

C305

150K

1/50

+

0.001

33/16

R361

ERASE

C309 4.7/50

R562

C363

C326 2.2/50

C313

R249

C401

470/16

2.7K

1/50

HEAD

C317

C365

330P

10/16

4.7/50

18K

Q202

IC401

R303

R317

C315

9014 C

180K

180K

LINE AMP.

BA4558

330P

OPE AMP.

8

C412

E

330P

C258

R245

3 +

1

C338 47/16

1/50

R563 2.7K

(1/2)

24

23

22

21

20

19

18

17

16

15

14

13

100

2 –

IC301

R364

SW302-E

SW302-D

1M

C259

R243

TA8189N

1/50

100

R408

R412

RECORD/PLAYBACK AMP.

P

R

P

R

Q203 9014 C

2.7K

12K

1

2

3

4

5

6

7

8

9

10

11

12

LINE AMP.

R410

R405

R241

C263

12K

10K

R320

150K

1/50

0.0033(ML)

CNH107

C302

0.001(ML)

C310

R312 4.7K

R250 18K

C408

LB

330P

180K

C316

C261

R247

4.7/50

R413

R310

3.9K

4.7/50

22/16 C320 4.7/50

180K

C314 4.7/50

CNS107

130P

470

C304 .001 0

C364

C308 0.033(ML)

R308 150K

R325 10K

R324

C323

R316 330K

C312 0.0082(ML)

TAPE

RADIO

CD/LINE

1/50

R506

R404

10K

R407

C409

0.0033(ML)

C415

100/16

330P

1K

330P

C410

C416

TAPE2

SW404-D

4.7/50

220/16

PLAYBACK HEAD

C318

R362

SW404

L-CH

C366

R304

10/16

270

FUNCTION SELECTOR

C411

1

1

GB

10K

R368

R314

R355

10K

2

2

RB

L302

18K

3

3

C306

18K

22K

R409

F

2.7mH

TAPE SPEED

33/16

R533 VR501

12K

R561

R-CH

R306

R318

47K

470(B)

47

2.2K

R411

C515

C527

56

12K

C362

C521

3.9K

2.7K

6

–

C413

R403

0.015(ML)

0.0033(ML)

(2/2)

1/50

L303

R321

Q503

R560

10K

5 +

7

C517

4

56K

150P

22mH

12K

9015 C

IC401

TAPE

SW403

SPEED

BA4558

DUBBING SPEED/

CONTROL

OPE AMP.

SW301

R323

AC BIAS CIRCUIT

BUILT-IN MICROPHONE/

BEAT CANCEL

10K

FM MODE

C357

C356

C355 0.0015(ML)

R333

8050

C

SW302-A

SW403-B

R508

KA7809

R452

SW302-F

HIGH/FM STEREO

47K

A

B

C

27K

NORMAL/FM STEREO

R510

C404

IC502

Q301

P

R

MIC/FM MONO

10K

10/16

L-CH

R454

120P

430P

BIAS OSC.

P

SW302

10K

VOLTAGE

2.2K

C353

R512

REGULATOR

G

T301

RECORD/

Q504

J2

GND

0.0056(ML)

R330R

PLAYBACK

10K

BIAS

9014 C

CD/LINE

OSCILLATION

R332

100

TAPE

1

3

R-CH

R453

TAPE

C354

10

C352

C351

0.022

SPEED

2

2.2K

0.01(ML)

10K

Q505

100/16

R513

CONTROL

R451

9014 C

C511

47K

TAPE

C512

220/16

SPEED

CONTROL

0.1

L501

47 H

FM SIGNAL
MW/SW1/SW2 SIGNAL
PLAYBACK SIGNAL	R336
	100

H	RECORD SIGNAL

• NOTES ON SCHEMATIC DIAGRAM can be found on page 6.

1

2

3

4

5

6

Figure 8 SCHEMATIC DIAGRAM (1/6)

– 8 –

WQ-740W/WQ-780W

SW403

DUBBING SPEED/

BUILT-IN MICROPHONE/

R531

FM MODE

1K

MIC/FM MONO

SW403-A

L/FM STEREO

R345

R557

R565

R344

R552

MIC2

H/FM STEREO

1K

1K

5.6K

4.7K

R346

C344

4.7K

C533

R556

C341

470K

4.7/50

150K

4.7/50

4.7/50

Q302

Q508 9014 C MIC AMP.

Q303

9014 C

VR301

9014 C

MIC AMP.

R341 MUTE

MICROPHONES

50K(B)

10K

C532

R555

C342

C223

MIC

MIC1

470/16

500P

C536

C343

4.7K

0.0015

VOLUME

D520

1N4148

47/16

500P

R558

R343

R534

R553

R554

4.7K

33

330

C345

0.0047(ML)

680

680

1

1

MIC101

R350

C347

C346

R351

3.9K

10/16

R349

4.7/50

1K

2.2K

2

2

BUILT-IN

C529

MICROPHONE

0.022

CNS109

CNH109

R217

330

R450

4.7K

SW401

LIVE

HALL

1

2

FROM GRAPHIC

SURROUND

SW402

6

MODE SELECT

3

EQUALIZER PWB

SURROUND ON/OFF

SW401-C

2

SW402-A

4

CN207

SW402

5

P12 1-F

R566

SW402-B

ON

OFF

100K

SURROUND

6

D526

ON/OFF

ON

OFF

HALL

7

LIVE

8

CD/LINE

1N4148

CN4

SW404-A

RADIO

SW401

SW401-B

SW401

TAPE

SW404

SURROUND

SURROUND

FUNCTION

MODE SELECT

MODE SELECT

SP4

SELECTOR

SW401-A

CNH106

SURROUND

C530

SW401-D

LIVE

HALL

C450

L-CH SPEAKERS

4.7/50

LIVE

HALL

2.2/50(N.P)

TWL

1

1

SP2

D515

L-CH

2

2

FULL-RANGE

1N4148

C459

CNS106

D402

D517

GND

3

3

2.2/50(N.P)

GND

1N4148

1N4148

4

4

R-CH

5

5

SP1

TWR

6

6

FULL-RANGE

C427

R-CH SPEAKERS

0.01(ML)

D519

SP3

1N4001

C434

SURROUND

Q402

C428

1000/10

R567

5

Q510

R421

9014 C

10

0.01(ML)

22K

POWER MUTE

9014 C

10K

2

4

MUTE

R442

C422

C424

POWER AMP.

C432

0.0015(ML)

0.18(ML)

10K

1/50

3

6

LA4508

C426

IC402

C430

100/16

14

7

100/16

R422

R441

C425

C429

120

R440 27K

C440 10/16

10K

100/16

12

9

100/16

C431

J1

R420

C421

C423

0.18(ML)

HEADPHONES

1/50

0.0015(ML)

10K

13

11

R423

FUSE

Q401

120

C433

RESISTOR

4.7 FUSIBLE D518

9014 C

1

8

1N4148

1000/10

POWER MUTE

D401

R501

F1

1N4001

C437

470/25

Q501

Q506

T1.25A

2SB1370

C469

D305

1N4148

D525

1N4148

8050 C

SWITCHING

L250V

VOLTAGE

220/16

REGULATOR

R548

R535

330/1W

100

C SWITCHING

D522

R545

POWER PWB-C

1N4148

22K

R564

R502

D509

SW505

22K

680

F501

R537

C502

VOLTAGE

T501

C508 0.1

C507 100/16

C505 10/16

1N4001

10K

Q5079014

0.1

T2A L250V

SELECTOR

SW404-B

POWER

D524

1N4148

CNS110

CNH110

TRANSFORMER

CD/LINE

RADIO TAPE

C504

D501

SO501

D505

0.1

AC220-240V

AC POWER

D504

INLET SOCKET

C522

50/60Hz

AC110-127V/

3300/25

1

1

220-240V

0.0033(ML) 0.0033(ML)

AC110-127V

50/60Hz

C417 C414

D502

50/60Hz

R416 10K

SW404

2

2

D523

FUNCTION

1N4148

SELECTOR

C501

0.1

D507

D501~D504'RL202DC

BATTERYS

1N4001

R415

10K

CNS102

C503

0.1

D503

DC15V['' D '' SIZE(UM/SUM-1,

R20 OR HP-2)BATTERYx10]

5

5

5

R419

4

4

3

3

C473

3.3K

C471

R472

C474

2

2

820P

0.068

8.2K

820P

R418

1

1

1

R471

C472

CNH102

3.3K

8.2K

0.068

VCC

1

VR401-B

VR401-A

GND

50K(B)

50K(B)

2

VOLUME

VOLUME

LO0

3

C407

RO0

10/16

4

RI0

VOLUME PWB-B1

5

LI0

6

FROM GRAPHIC EQUALIZER PWB

C535

C537

CNS101

4.7/50

10/16

CN205

P12 1-C

R568

1

1

SW502

2

2

TAPE1 MAIN

1K

SW501

3

3

4

4

TAPE2 MAIN

5

5

SW503

6

6

+

TAPE2 PLAY

7

7

–

8

8

B

M501

9

9

M TAPE MOTOR

A

10

10

CNS105

CNS1

MAIN PWB-A

7

8

9

10

11

12

Figure 9 SCHEMATIC DIAGRAM (2/6)

– 9 –