Sony Walkman WM-FX571 Service Manual

– 1 –

Model Name Using Similar Mechanism WM-FX551/FX553
Tape Transport Mechanism Type MF-WMFX551-125

SERVICE MANUAL

Tourist Model

WM-FX571

RADIO CASSETTE PLAYER

Ver 1.0 1999. 03

SPECIFICATIONS

Radio section
Frequency range

FM : 87.5 – 108 MHz
AM: 531 – 1,602 kHz

Tape section
Frequency response

(Dolby NR off)

Playback : 20 – 18,000 Hz

Output

Headphones (2 REMOTE jack)
Load impedance 8 – 300 Ω

General
Power requirements

1.5 V
One R6 (size AA) battery
Rechargeable battery

Dimensions (w/h/d)

Approx. 109 × 79.2 × 29.4 mm
(4 3/8 × 3 1/8 × 1 3/16 inches) incl.
projecting parts and controls

Mass

Approx. 150 g (5.3 oz)
Approx. 210 g (7.5 oz) incl.
a battery and a cassette

Supplied accessories

Stereo earphones with remote
control MDR-WMF653 (1)
Battery charger BC-820T (1)
AC plug adaptor (1)
Rechargeable battery (NC-AA) (1)
Battery R6P (SR) (1)
Carrying pouch (1)

Design and specifications are subject to
charge without notice.

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

MICROFILM

– 2 –

TABLE OF CONTENTS

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

2. SERVICE NOTE.......................................................... 3

3. DISASSEMBLY

3-1. Case Assy ............................................................................ 4

3-2. Tuner Board ........................................................................ 4

3-3. Audio Board ........................................................................ 5

3-4. Cassette Lid Assy................................................................ 5

3-5. Tape Mechanism Deck ........................................................ 6

4. MECHANICAL ADJUSTMENTS..............................7

5. ELECTRICAL ADJUSTMENTS

Tape Section ............................................................................ 7

Tuner Section........................................................................... 8

6. DIAGRAMS

6-1. Block Diagram .................................................................... 9

6-2. IC Pin Description............................................................. 11

6-3. Printed Wiring Boards –Tuner Section– ........................... 13

6-4. Schematic Diagram –Tuner Section–................................ 17

6-5. Schematic Diagram –Audio Section– ............................... 20

6-6. Printed Wiring Board –Audio Section– ............................ 23

7. EXPLODED VIEWS

7-1. Cabinet Section ................................................................. 29

7-2. Audio and Tuner Board Section........................................ 30

7-3. Tape Mechanism Section .................................................. 31

8. ELECTRICAL PARTS LIST .................................... 32

Flexible Circuit Board Repairing

• Keep the temperature of the 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.

Notes on Chip Component Replacement

• Never reuse a disconnected chip component.

• Notice that the minus side of a tantalum capacitor may be dam-

aged by heat.

– 3 –

screw
(M1.4 × 5.0)

screw (M1.4

×

5.0)

TUNER board

screw (M1.7

×

4.0

)

screw
(M1.4 × 5.0)

JIG

AUDIO board

0

!¡

!™

!£

!¢

!∞

!§
!¶

9

8

7

6

5

4

3

2

1

SECTION 1

GENERAL

• LOCATION OF CONTROLS

SECTION 2

SERVICE NOTE

• Regarding the method of adjustment and voltage check, perform sections 3-1 and 3-2 of the DISASSEMBLY, and attach the JIG (ext ension
cable) to the AUDIO board as shown below.

JIG Part No.: J-2503-005-A

1 OPEN knob
2 Display window
3 PRESET + /AMS FF (Fast Forward) button
4 TUNING + button
5 TUNING – button
6 ENTER button
7 PRESET – /AMS REW (Rewind) button
8 MENU button
9 RADIO ON/BAND button
!º SET button
!¡ p /RADIO OFF button
!™ “” /REPEAT button
!£ VOLUME control
!¢ C HOLD knob
!∞ 2 REMOTE jack
!§ Battery case
!¶ DC IN 1.5V jack

– 4 –

1

screw (M1.7 × 6)

5

TUNER board

4

3

screw

(M1.4

×

4.5)

7

guide (TU)

6

2

screw (M1.7 × 3)

1

screw (M1.7 × 6

)

6

case assy

4

claws

3

screws

(M1.4

×

2.2)

1

screw

(M1.4

×

2.2)

2

screw

(M1.4

×

3.0)

5

CASE ASSY

TUNER BOARD

AUDIO BOARD

CASSETTE LID ASSY

TAPE MECHANISM DECK

SET

SECTION 3

DISASSEMBLY

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

3-1. CASE ASSY

3-2. TUNER BOARD

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

– 5 –

2

screw (M1.4 × 2)

5

cassette lid assy

3

screw (M1.4 × 1.6

)

1

OPEN button

4

7

AUDIO board

1

Unsolder the 3 places.

2

battery terminal (–)

4

battery terminal (+)

3

Unsolder the 5 places.

5

Flexible board

6

3-3. AUDIO BOARD

3-4. CASSETTE LID ASSY

– 6 –

2

1

3

4

reel ornament

5

tape mechanism deck

3-5. TAPE MECHANISM DECK

– 7 –

PRECAUTION

1. Specified voltage : 1.3V

2. Switch position
MENU button : a NR light off (OFF)

: AVLS light off (OFF)

TAPE SECTION 0 dB=0.775 V

Test T ape

Tape Speed Adjustment

Procedure :

1. Playback WS-48A (Tape center part) in the FWD state and
adjust RV601 so that the frequency counter reading becomes
3,000 Hz.

Specification V alue:

Digital frequency counter

2,970 to 3,030 Hz

2. Playback WS-48A (Tape center part) in the REV state.
Check that frequency counter reading is within 60 Hz of the
reading of step1.

Adjustment Location :

[MAIN BOARD] — SIDE A —

Torque meter

CQ-102C

CQ-102RC

CQ-201B

Mode

FWD

FWD
Back Tension

REV

REV
Back Tension

FF
REW

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

set

16

Ω

2

REMOTE jack (J701)

+
–

Frequency counter

RV601 : Tape speed

SECTION 4

MECHANICAL ADJUSTMENTS

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 (1.3V) to
perform the adjustments.

Torque Measurement

Meter reading

20 to 30 g · cm
(0.28 to 0.42 oz · inch)

0.4 to 2.0 g · cm
(0.0056 to 0.028 oz · inch)
20 to 30 g · cm
(0.28 to 0.42 oz · inch)

0.4 to 2.0 g · cm
(0.0056 to 0.028 oz · inch)
More than 40 g · cm
(More than 0.56 oz · inch)

Type

WS-48A

Signal

3kHz, 0dB

Purpose

Tape Speed Adjustment

SECTION 5

ELECTRICAL ADJUSTMENTS