Sony WMFX-141 Service manual

WM-FX141

SERVICE MANUAL

Ver 1.3 1999. 05

With SUPPLEMENT-1 (9-923-296-81) With SUPPLEMENT-2 (9-923-296-82)

US Model

AEP Model

E Model

Model Name Using Similar Mechanism WM-FX101 Tape Transport Mechanism Type MF-WMFX103-48

SPECIFICATIONS

Radio Frequency

FM : 87.6 – 108 MHz (US, Chilean, Latin America, Central and

South America Models) : 65.0 – 107.9MHz (East European Model) : 87.6 – 107.9 MHz (Other Models)

AM : 530 – 1,710 kHz (US, Chilean, Latin America, Central and

South America Models) : 531 – 1,602kHz (Other Models)

Power requirements

3V DC batteries R6 (size AA) × 2 External DC 3V power sources

Battery life

(Aprroximate hours)

Battery Playback Radio Sony alkaline LR6 (SG) 16 hrs 48 hrs Sony R6P (SR) 4.5 hrs 16 hrs

Dimensions

93.9 × 118.5 × 35.9 mm (w/h/d) (33/4 × 43/4 × 13/16 in.) incl. projecting parts

Mass

205g (7.3 oz) incl.batteries

Supplied accessories

• Stereo headphones or earphones (1)

• Belt clip (1)

Design and specifications are subject to change without notice.

MICROFILM

RADIO CASSETTE PLAYER

TABLE OF CONTENTS

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

2. DISASSEMBLY

2-1. Cabinet (Rear) ································································· 4 2-2. Mechanism Deck and Main Board ································· 4 2-3. Main Board ····································································· 5 2-4. Cassette Lid····································································· 5 2-5. Dial Pointer Setting························································· 5

3. ADJUSTMENT

3-1. Mechanical Adjustment ·················································· 6 3-2. Electrical Adjustment······················································6

4. DIAGRAMS

4-1. Block Diagram ································································ 9 4-2. Schematic Diagram ······················································· 11 4-3. Printed Wiring Board ···················································· 13 4-4. IC Block Diagram ························································· 17

5. EXPLODED VIEWS

5-1. Cabinet and Board Section ··········································· 18 5-2. Mechanism Section (MF-WMFX103-48) ···················· 19

6. ELECTRICAL PARTS LIST ······································· 20

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.

Flexible Circuit Board Repairing

• Keep the temperature of soldering iron around 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.

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SECTION 1

GENERAL

This section is extracted from instruction manual.

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DISASSEMBLY

Note : Disassemble the unit in the order as shown below.

SECTION 2

Cabinet (Rear) Mechanism deck and main board

Main board Cassette lid

Dial pointer setting

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

2-1. CABINET (REAR)

Cabinet(rear)

Cassette lid

Open the cassette lid and release claw A.

Remove the cabinet(rear).(Release

all claws

from M in alphabetical order.)

2-2. MECHANISM DECK AND MAIN BOARD

Remove the mechanism deck and main board in the direction of the arrow.

head flexible board

mechanism dec and MAIN board

note for installation : Make sure to put the head flexible board to ditch before install the mechanism deck and MAIN board.

— 4 —

2-3. MAIN BOARD

head flexible board

claws

MAIN boar

2-4. CASSETTE LID

Release the catch A.

Release the catch B.

Cassette lid (Remove it in the direction of the arrow)

Front cabine

2-5. DIAL POINTER SETTING

Pointer

B



Align pointer with arrow marked side as shown in Fig.1 and then fit to groove in the order of

A



Rotate tune knob fully to arrow direction.

and B.

Fig. 1

— 5 —

Align

Pointe

SECTION 3

ADJUSTMENTS

3-1. MECHANICAL ADJUSTMENTS

Precaution

1. Clean the following parts with a denatured-alcohol-moistend swab :

playback head pinch roller capstan rubber belts

2. Demagnetize the playback head with a head demagnetizer.

3. Do not use a magnetized screwdriver for the adjustments.

4. After the adjustments, apply suitable locking compound to the parts adjusted.

5. The adjustments should be perfomed with the rated power supply voltage (2.5V) unless otherwise noted.

Torque Measurement

Mode Torque meter Meter reading

FWD FWD

Back T ension

FF, REW

CQ-102C

CQ-201B

20 to 42 g•cm (0.28 to 0.58 oz•inch) less than 2 g•cm (less than 0.03 oz•inch) more than 60 g•cm (more than 0.83 oz•inch)

3-2. ELECTRICAL ADJUSTMENTS

Precaution

• Supplied voltage : 2.5V

• Switch and control position

TAPE switch : NORM VOLUME control : maximum AVLS switch : OFF

TAPE SECTION

• FUNCTION switch : TAPE

Test tape

Type Signal Used for

WS-48A 3kHz, 0dB Tape Speed Adjustment

Tape speed adjustment

Tape selection adjustment : NORM

Procedure :

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

Ω

0dB=0.775V

frequency counter

set

J302(phones)

Adjustment V alue: normal tape speed Adjust the tape speed adjustment R V601, so that the freqency counter reading becomes 3,000Hz.

Specification Value:

Digital frequency counter

2,945 to 3,015Hz

Frequency difference between the beginning and the end of the tape should be within 1.5% (45Hz).

Adjustment Location :

— 6 —

TUNER SECTION

[AM]

BAND: AM Signal generator

AM RF signal generator

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

Put the lead-wire antenna close to the set.

0 dB = 1 µV

• Repeat the procedures in each adjustment several times for the maximum level meter indication.

• The frequency coverage and tracking adjustments should be finally done by the trimmer capacitors.

AM IF ADJUSTMENT

Adjust for a maximum reading on level meter.

T1 455kHz

AM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L1 620kHz(800kHz)

CT1 1,400kHz(1,300kHz)

[FM]

BAND : FM Signal generator

FM RF signal generator

75kHz(100%) amplitude modulation by 1kHz signal. Output level: as low as possible

set

0.01µF

J302 (phones)

antenna termina

level mete

Ω

AM FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L4 505kHz(516.5kHz)

CT4 1,750kHz(1,631.5kHz)

FM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L2 86.0MHz[64MHz]

CT2 109.5MHz

FM FREQUENCY COVERAGE ADJUSTMENT

Adjust for a maximum reading on level meter.

L3 86.0MHz[64MHz]

CT3 109.5MHz

( ) :E, Mexican, East European, AEP

[ ] : East European

Adjustment Location: Main board (See page 8)

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