Sony WMFX-487, WMFX-483, WMFX-485 Service manual

WM-FX483/FX485/FX487

MICROFILM

SERVICE MANUAL

Ver 1.0 1998.03

Photo : WM-FX485

Manufactured under license from Dolby Laboratories Licensing Corporation. “DOLBY” and the double-D symbol a are trademarks of Dolby Laboratories Licensing Corporation.

Model Name Using Similar Mechanism WM-EX402/EX404/EX405/EX406 Tape Transport Mechanism Type MF-WMFX483-147

SPECIFICATIONS

US Model

WM-FX487

Canadian Model

WM-FX485/FX487

AEP Model

E Model

WM-FX483/FX485/FX487

Design and specifications are subject to change without notice.

RADIO CASSETTE PLAYER

TABLE OF CONTENTS

1. GENERAL ······································································ 3

2. DISASSEMBLY

2-1. Cabinet (Front) Assy ·························································· 5 2-2. Main Board········································································· 6 2-3. Mechanism Deck ································································ 6 2-4. Cassette Lid Sub Assy ························································ 7 2-5. Display Board····································································· 7

3. MECHANICAL ADJUSTMENT······························· 8

4. ELECTRICAL ADJUSTMENT ································ 8

5. DIAGRAMS

IC Block Diagrams··························································· 11 5-1. Block Diagram ································································· 13 5-2. Printed Wiring Board -Main Section- ······························ 15 5-3. Schematic Diagram -Main Section- ································· 17

Printed Wiring Board -Display Section-(FX483/FX485

5-4. 5-5. Schematic Diagram

Printed Wiring Board -Display Section-(FX487

5-6. 5-7. Schematic Diagram 5-8. IC Pin Function ································································ 27

-Display Section-(FX483/FX485

-Display Section-(FX487

) ················ 25

)··19

) ···· 21

) ·············· 23

6. EXPLODED VIEWS

6-1. Cassette Lid Section ························································· 29 6-2. Cabinet Section································································· 31 6-3. Mechanism Deck Section················································· 32

Flexible Circuit Board Repairing

• Keep the temperature of the soldering iron aroud 270˚ C during repairing.

• Do not touch the soldering iron on the same conductor of the circuit board (within 3 times).

• Be careful not to apply force on the conductor when soldering or unsoldering.

Notes on chip component replacement

• Never reuse a disconnected chip component.

• Notice that the minus side of a tantalum capacitor may be damaged by heat.

7. ELECTRICAL PARTS LIST ··································· 33

— 2 —

SECTION 1

GENERAL

— 3 —

— 4 —

• This set can be disassembled in the order shown below.

SECTION 2

DISASSEMBLY

2-1. CABINET (REAR) ASSY 2-2. MAIN BOARD

2-4. CASSETTE LID SUB ASSY

2-3. MECHANISM DECK

Note : Follow the disassembly procedure in the numerical order given.

2-1. CABINET (REAR) ASSY

Screw (B 1.7 × 12), tapping

2-5. DISPLAY BOARD

Open the lid battery case.

Claws

Cabinet (rear) assy

Claws

— 5 —

2-2. MAIN BOARD

Mechanism deck

Cabinet (front) assy

MAIN board

Screw (1.7 × 2.5), tapping

PC board, flexible

HEAD flexible board

2-3. MECHANISM DECK

• Use caution when installing the cassette holder assy

Install the cassette holder with the spring (lid up) as shown below in the drawing so that it fits into the holes on the cabinet front assy. Once installed, f it the left and right pieces on.

Cabinet (front) assy

— 6 —

2-4. CASSETTE LID SUB ASSY

Cassette lid sub assy

Cabinet (front) assy

• Press on the left & right clips from the

rear of the Cabinet (front) assy, and remove the boss.

Spring (lid up)

Cassette lid sub assy

2-5. DISPLAY BOARD

Screws

Holder

Cabinet (front) ass

— 7 —

DISPLAY board

Cassette lid

SECTION 3

MECHANICAL ADJUSTMENT

SECTION 4

ELECTRICAL ADJUSTMENT

PRECAUTION

1. Clean the following parts with a denatured-alcahol-moistened sweb : Playback head Pinch roller Rubber belt Capstan

2. Demagnetize the playback head using a demagnetizer.

3. Do not use a magnetized screwdriver for adjustments.

4. After adjusting, apply screw-locking compound onto the adjusted parts.

5. Unless specified otherwise, use a specified voltage (3.0V) to perform the adjustments.

Torque Measurement

Mode

FWD FWD

Back Tension

REV REV

Back Tension FF REW

Torque meter

CQ-102C

CQ-102RC

CQ-201B

Meter reading

20 - 42 g · cm (0.28-0.58 oz · inch)

Less than 2 g · cm (Less than 0.03 oz · inch)

20 - 42 g · cm (0.28-0.58 oz · inch)

Less than 2 g · cm (Less than 0.03 oz · inch)

More than 50 g · cm (More than 0.69 oz · inch)

PRECAUTION

1. Specified voltage : 3.0V

2. Switch and control position MENU switch

MENU → TAPE → SET : NORM MENU → SOUND → SET : No message MENU → AVLS → SET : No message MENU → aNR → SET : OFF (FX485/FX487)

VOL control : maximum

CASSETTE SECTION

T est Tape

Type

WS-48A

Tape Speed Adjustmnet

Procedure :

Test tape WS-48A (3kHz, 0dB)

Signal

3kHz, 0dB

Set

Tape Speed Adjustment

Ω

Purpose

Frequency counte

+ –

PHONES jack

1. Playback WS-48A (T ape center part) and adjust RV601 so that the frequency counter reading becomes 2,985Hz to 3,015Hz.

2. Playback WS-48A (Tape top and end). Check that frequency counter reading is within 1.5% of the reading of step1.

Adjustment Point :

RV601

— 8 —

TUNER SECTION

Set

PHONES

+ –

FM RF signal generator

75kHz frequency deviation by 1KHz signal. Output level : as low as possible.

0.01µF to IC1 pin

Level meter

(AC : 0.5 – 5V range)

Ω

)

[AM]

Setting : RADIO ON/BAND switch : ON/AM

AM T uning Volta ge Adjustment

digital voltmete

MAIN board

(VT)

(GND)

–

AM TUNING VOL T A GE ADJUSTMENT

Adjust for a 1.5 ± 0.03Vde reading on digital voltmeter.

530kHz

(531kHz)

( ) : Except US, Canadian models

AM IF Adjustment, AM Tracking Adjustment

AM RF signal generator

Put the lead-wire antenna close to the set.

[FM]

Setting : RADIO ON/BAND switch : ON/FM

FM T uning V oltage Adjustment

digital voltmete

MAIN board

(VT)

(GND)

+ –

FM TUNING VOL T A GE ADJUSTMENT

Adjust for a 10.0 ± 0.03Vde reading on digital voltmeter.

L2 108MHz

FM T racking Adjustment

30% amplitude modulation by 400Hz signal. Output level : as low as possible

• Repeat the procedures in each adjustment several times, and the frequency coverage and tracking adjustments should be finally done by the trimmer capacitors.

Adjust for a maximum reading on level meter.

( ) : Except US, Canadian models

Adjust for a maximum reading on level meter.

( ) : Except US, Canadian models

Level meter

(AC : 0.5 – 5V range

Ω

Set

+ –

jack

AM IF ADJUSTMENT

1,000 (999) kHz

AM TRACKING ADJUSTMENT

L4 620kHz (621kHz)

CT2 1,400kHz (1,395kHz)

FM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

CT1 108MHz

[ ] : East European model

87.5MHz

[65.0MHz]

— 9 —

[MAIN BOARD] — SIDE A —

FM TRACKING ADJUSTMENT

CT1 L1

AM TUNING VOLTAGE ADJUSTMENT

AM TRACKING ADJUSTMENT L4 (FERRITE BAR ANTENNA)

AM TRACKING ADJUSTMEN

CT2

FM TUNING VOLTAGE ADJUSTMENT L2

AM IF ADJUSTMENT T1

[MAIN BOARD] — SIDE B —

(ANT)

J301

VCC

DATAREMO

GND

TP(ANT)

FL1

RV301

VOL

CT2

(VT)

(GND)

C34

TP(GND)

CT1

R19

C16

R18R21

TP(VT)

R20

S701

C17

HOLD

OFF

EXCEPT

US,CND,C&SA

FX485/

FX487

MODELS

FX483

MODEL

C205 C105

FX485/

FX487

FX483

C36

MODELS

MODEL

C37

S601

CONTROL

RVS

REW

FWD

C701

C306

C606

— 10 —

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