Sharp WQT-370-A Service manual

SHARI=

SERVICE

MANUAL

SYOC7WQT370AG

WQ-T37OA(

In the interests of user-safetythe set should be restored to its original condition and only parts identical to those specified be used.

SPEC,F,CAT,ONS STR,NG,,+G OF D,AL CORD NAMES OF PARTS DISASSEMBLY

REMOVING AND REINSTALLING THE MAIN PARTS

ADJUSTMENT EXPLODE,, VIEW

BLOCK DIAGRAM SCHEMATIC DIAGRAM/WIRING SIDE OF P.W.BOARD

REPLACEMENT PARTS LIST.

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INDEX TO CONTENTS

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Page

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SHARP CORPORATION

FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT, PLEASE REFER TO THE OPERATION MANUAL.

SPECIFICATIONS

General

Power source:

AC 230 - 240 V, 50 Hz DC 12 V [“D” size

IUM/SUM-l,R20

HP-2 ) battery x 8)

Output power:

(Left + Right + Extra bass)

PMPO; 60 W

(15

W + 15 W + 30

(AC operation)

MPO; 27 W (7.5 W + 7.5 W + 12

(AC operation)

RMS;l6W(4W+4W+8W)

(DC operation, 10% T.H.D.)

Speakers:

8 cm (3-l

/8”)

free-edge super woofer

12 cm

(4-3/4”)

free-edge woofer x 2

Tweeter x 2

Input impedance:

Mixing mic; 600 ohms CD/Line in; 50 k ohms

Load impedance:

Headphones; 16-50 ohms (recommended 32 ohms)

Dimensions:

Weight:

Width; 560 mm

Height; 210 mm Depth; 187 mm

5 kg 11 1

122-l/16”)

(8-5/16”)

(7-3/8”)

Ibs.)

without batteries

STRINGING

1. Turn tt-le drum fully in the stretch its cord over the parts in the numerical order.

2. Then turn the tuning control shaft fully in the direction shown in Fig. 2-2 and fix its pointer as shown in Fig. 2-1.

drrectron (8,

shown in Fig. 2-2 and

Radio

Frequency range:

Tape recorder

Tape:

Frequency response: 60 - 12,000 Hz (Normal tape) Signal/noise ratio:

Wow and flutter:

Specifications for this model are subject to change without prior notice.

OF DIAL CORD

FM; 87.6 - 108 MHz AM; 526.5 -

I,6065 kHz

Compact cassette tape

55 dB (TAPE 1, playback) 50 dB (TAPE 2, recording/playback)

0.15 oh (WRMS)

‘0”

Pdnt

Dial Cord

Asiy(g4g)

Figure 2-1

‘I

drum

1236)

Turns

Figure 2-2

-2.-

NAMES OF PARTS

Volume Control

2. Graphic Equalizer Controls

3. Headphones Socket

4. Surround Speaker Sockets

5. Beat Cancel Switch

6. Dubbing Speed Switch

Power/Function Switch

8. CD/Line Input Sockets

9. Mixing Microphone Socket

10. Radio Band Selector

11. Tuning Control

12. Power Indicator

13. Surround indicator

14. Extra Bass Indicator: X-BASS

15. Extra Bass Switch: X-BASS

16. Surround Switch

17. FM Stereo Indicator

18. Bass Boost Horn

19. Cassette Compartment

20. Tape Mode Switch

21. TAPE 2) Pause Button: II

22. TAPE 1, 2) Stop/Eject Button: N

23. TAPE 2) Fast Forward Button:

24. TAPE 2) Rewind Button:

25. TAPE 1, 2) Play Button:

26. TAPE 2) Record Button:

27. FM Telescopic Rod Aerial

28. AC Power Input Socket

29. Battery Compartment

-3-

DISASSEMBLY

Caution

unit and reassembling it, to keep its safety and excellent performance:

1. Take cassette tape out of the unit.

2. Be sure to remove the power supply plug from the

3. Take

4. Take sufficient care on static electricity of integrated

STEP REMOVAL PROCEDURE

2 1

on Disassembly

the below-mentioned notes when disassembling the

wall outlet before starting to disassemble the unit and remove the batteries from the unit.

off

nylon bands or wire holders where they need be removed when disassembling the unit. After servicing the unit, be sure to rearrange the leads where they were before disassembling.

circuits and other circuits when servicing.

FIGURE

Battery

Screw..............(A2)x

Screw..............(Bl)x

. . . . . . . . . . . . (A,)

lid..

;;;pnism i2’ ~~ecrharli.“::.mode....iB2)x, 1

Main PWB 1. Screw

(with Frame) 2. Tip

4 Socket PWB 1.

Power

PWB

3. Screw

1. Screw

....*.........(B3)x!j

Socket..............(B4)x

..............

................

Screw..............(Dl)x

..............(El)x

(Cj)x6

((-2)

4-2.3

3 4-4

4-1

4-3

4-4

Rear

Cabins

Plug-

PWB

(Av3)x

Figure 4-2

-hJvl;fanism

-?a

(B3lx5

d3xlOmm

:IOmm

,(C2) xl

Figure

(Ahx8

d3x65mm

4-I

Main

PWB

(C 11x4 83xI2mm

Figure 4-3

Socket

* (El) x2

04 x12mm

Figure 4-4

PWB

(DlJx3 03 xl Omm

Power PWB

-4-

REMOVING

AND

REINSTALLING THE MAIN PARTS

TAPE MECHANISM SECTION

Perform steps 1 and 2 of the disassembly method to remove the tape mechanism.

How to remove the playback, erase and record/playback

heads (See Fig. 5-l

1. Remove the two screws

2. Remove the two screws the record/playback head.

3. Remove the two screws

Note: Be careful not to lose the head azimuth springs.

(Al)

to remove the playback head.

(A2)

and shield cover

iA4j

to remove the erase head.

(A3)

to remove

How to remove the drive belt

1. Remove the four screws (Cl i to remove the flywheel bracket and switch bracket.

2. Remove the drive belt iC2).

How to remove the flywheel (See Fig.

Remove the capstan metal

Note: Be careful not to lose the three washers.

(See

Figs. 5-3 and 5-4.)

5-4.)

(Dl)

and pull out the flywheel.

Figure 5-l

How to remove the pinch roller (See Fig. 5-2.)

1. Move the pinch roller

to remove it from the play lever.

2. Move the pinch roller spring @to remove it from the pinch roller unit.

3. Remove the pinch roller in the direction of arrow

sprin$‘(Bl)

(Bl)

in the direction of arrow

Metal

How to remove the motor. (See Fig. 5-4.)

1. Remove the three screws (El) to remove the motor.

cc 11x1

82.6x

IOmm

Figure 5-3Figure 5-3

(El)x3

P2x6mm

$@;;;a

Figure 5-2

Pinch Rol

ler

,wheel(D2)

Figure 5-4

-5-

ADJUSTMENT

As for adjusting method refer to the relevant explanation in Service Manual “ADJUSTMENT PROCEDURES OF AUDIO PRODUCTS”.

MECHANISM SECTION

Driving Force check

Torque Meter

Play: TW-2412

Torque Check

Torque Meter

Play: TW-2111 Fast forward: TW-2231 ) Rewind: TW-2231

Head Azimuth

Test Tape

MTT-114

Tape Speed

Test Tape Adjusting Point Specified Value

Normal

speed

MTT-111 Tape 2: VR501 3,000 + 300 Hz (Load

35 to

Tape 1

Specified Value

Over 140 g

Specified Value

Tape 2

u.cm

Instrument Connection

Speaker terminal (Load resistance: 4 ohms)

30 to 65

80 to 135 g.cm

a.cm

to 135 g.cm

Instrument

onnection

Speaker

terminal

resistance: 4 ohms)

TAPE

SECTION

Position of each switch or control Volume Beat cancel switch Graphic equalizer

Tape speed

Mechanism mode Function

Bias Oscillation Frequency/Bias Current check

Beat cancel B: -2 t 2 kHz for A

Resistor

measurement:

for

100 ohms

Max A/STEREO Center

Normal

2 Tape

Specified Value

A: 97 + 4 kHz

-7 f2 kHz for

383~5

. Erase Current check

Specified Value

Resistor for measurement: 1 ohm

65 4 20

. Playback Amplifier Sensitivity check

Test Tape Specified

MTT-118 1.0 V t 3 dB

Vaiue

Instrument Connection

Speaker terminal

(Load resistance: 4 ohms)

-1

TAPE2 AZIMUTH AfJJUSTWNT

TAPE1

AZIMUTH

ADJUSTMENT SCREW

Figure 6 ADJUSTMENT POINTS

SCREIW

ISOCKET PWB-~31

SP(R)

CvP74Z

MAIN PWB-Al

TAPE2 NORMAL

r---L

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