Sony WMFX-451 Service manual

WM-FX451

SERVICE MANUAL

Ver 1.3 2004. 03

SPECIFICATIONS

Frequency range FM :

87.5 – 108 MHz AM : 530 – 1710kHz (US, 7E model) 531 – 1602kHz (EXCEPT US, 7E model)

Battery life (Aprrox. hours)

Sony alkaline LR6 (SG) Sony R6P (SR) playback 24 7.5 radio 33 13

Power requirements 3V DC batteries R6 (AA) x2/External DC 3V power sources Dimensions 112.5x87.3x35.2 mm (4 1/2 x 31/2 x17/

projecting parts and controls

Mass Approx. 155g (5.5 oz)

Approx. 235g (8.3 oz) incl. batteries, a cassette and headphones

Supplied accesories Stereo headphones (1)/Belt clip (1)

US Model

AEP Model

E Model

Model Name Using Similar Machanism WM-FX453 T ape Tr ansport Mechanism Type MF-WMFX453-114

inches) (w/h/d) incl.

9-923-305-12

Design and specifications are subject to change without notice

RADIO CASSETTE PLAYER

Sony Corporation

Personal Audio Company Published by Sony Engineering Corporation

TABLE OF CONTENTS

Specifications ........................................................................... 1

1. GENERAL

Location of parts and controls............................................ 3

2. DISASSEMBLY

2-1. Cabinet (Rear) Sub Assy Removal ............................. 4

2-2. Main Board Removal ................................................. 5

2-3. Mechanism Deck Removal......................................... 5

2-4. Holder, Cassette Assy Removal.................................. 6

2-5. Display Board Removal ............................................. 6

3. ADJUSTMENTS

3-1. Mechanical Adjustments ............................................ 7

3-2. Electrical Adjustments................................................ 7

4. DIAGRAMS

4-1. Explanation of IC Terminals..................................... 10

4-2. Block Diagram...........................................................11

4-3. Printed Wiring Boards .............................................. 13

4-4. Schematic Diagram................................................... 17

5. EXPLODED VIEWS

5-1. Cabinet Section......................................................... 23

5-2. Mechanism Section (MF-WMFX453-114) .............. 24

6. ELECTRICAL PAR TS LIST................................... 25

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 damaged by heat.

• HOW TO CHANGED THE CERAMIC FILTERS

This model is used two ceramic filters of CF2 and X2. You must used same type of color marked ceramic filters in order to meet same specifications. Therefore, the ceramic filter must changed two pieces together since it’s supply two pieces in one package as a spare parts

mark

CF2

mark

Mark Center Frequency

red 10.70MHz

blue 10.67MHz

orange 10.73MHz

black 10.64MHz white 10.76MHz

– 2 –

LOCATION OF PARTS AND CONTROLS

SECTION 1

GENERAL

This section is extracted from instruction manual.

• Abbreviation FR : French E : Radio section : FM MONO/ST switch 7E : Radio section : DX/LOCAL switch

– 3 –

DISASSEMBLY

The equipment can be removed using the following procedure.

Set

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

2-1. CABINET (REAR) SUB ASSY REMOVAL

Lid, Batt

Main boardCabinet (rear) sub assy Holder, cassette ass

SECTION 2

Mechanism deck

Display board

Holder, Cassette

Claws

!º

!¡

!£

Cabinet, Front ass

Cabinet (Rear) sub assy

!™

Claws

– 4 –

2-2. MAIN BOARD REMOVAL

Main board

Remove solder

Terminal (–), Batt

Screw (M1.4), Tooth (WH)

Terminal (+), Bat

Flexible board for head

2-3. MECHANISM DECK REMOVAL

Claws

FPC1

Cabinet, Front assy

Mechanism deck

Claws

Cabinet, Front ass

– 5 –

2-4. HOLDER, CASSETTE ASSY REMOVAL

Spring (Lid up)

• Use caution when installing the holder, cassette assy

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

Holder, Cassette assy

Cabinet front assy

2-5. DISPLAY BOARD REMOVAL

• Press on the left & right clips from the rear of the cabinet fr ont assy . and remo ve the boss.

Screws

Cabinet, Front assy

Screws

– 6 –

Display board

Holder, Cassette assy

SECTION 3

RV601

ADJUSTMENTS

3-1. MECHANICAL ADJUSTMENTS

PRECAUTION

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

playback head pinch roller capstan rubber belt

2. Dema gnetiz e the pla ybac k head with a head dema gnetiz er.

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 performed with the rated power supply volta ge (2.5 V) unless otherwise noted.

Torque Measurement

Mode Torque Meter Meter Reading

FWD FWD less than 2 g • cm

back tension (less than 0.03 oz• inch) REV REV less than 2 g • cm

back tension (less than 0.03 oz• inch) FF, REW CQ-201B

CQ-102C

CQ-102RC

20 - 42 g • cm

(0.28 -0.58 oz• inch)

20 - 42 g • cm

(0.28 -0.58 oz• inch)

more than 60 g • cm

(more than 0.83 oz• inch)

3-2. ELECTRICAL ADJUSTMENTS

PRECAUTION

• Supplied v olta ge : 2.5V.

• Switch and control position T APE s witc h : NORM MODE switch : d VOLUME control : maximum A VLS s witc h : NORM

Test T ape

Type Signal Used for

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

Tape Speed Adjustment

Procedure :

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

set

frequency counte

Ω

phones jack

1. Pla ybac k WS-48A (tape center par t) in the REV state and adjust

RV601 so that the frequenc y counter reading becomes 3,000Hz ± 15Hz.

2. Pla ybac k WS-48A (tape center) in the FWD state .

Check that frequency counter reading is within 1.5% of the reading of step 1.

Adjustment Location :

– 7 –

TUNER SECTION

)

AM Section

BAND : AM

AM RF signal generator

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

FM Section

BAND : FM

FM RF signal generator

22.5kHz frequency deviation by 400Hz signal. Output level : as low as possible

set

Put the lead-wire antenna close to the set.

Ω

J301 (phones)

0.01

level mete

(ANT TAP (GND)

no mark : US, 7E model < > : EXCEPT US, 7E model

AM IF ALIGNMENT

Adjust for a maximum reading on level meter.

T1 1000kHz < 999kHz>

AM FREQUENCY COVERAGE ADJUSTMENT

Adjust part Frequency display

L4 530kHz < 531kHz> 1.4 ± 0.1V< 1.4 ± 0.1V>

AM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L1 620kHz < 621kHz>

CT1 1,400kHz< 1,395kHz>

FM FREQUENCY COVERAGE ADJUSTMENT

Adjust part Frequency display

L3 87.5MHz< 87.5MHz> 2.4 ± 0.1V< 2.4 ± 0.1V>

Confirmation 108MHz <108MHz>

FM TRACKING ADJUSTMENT

Adjust for a maximum reading on level meter.

L2 87.5MHz <87.5MHz>

Confirmation 108MHz <108MHz>

reading on digital

voltmeter.

reading on digital

voltmeter.

less than 10V

• Abbreviation 7E : Radio section : DX/LOCAL switch

* Repeat the procedures in each adjustment several times, and the

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

Frequency Coverage Adjustment

Setting :

(VT)

[MAIN BOARD] (Side B)

(GND)

GND

digital voltmete

(DC range)

C21

– 8 –

SECTION 4

DIAGRAMS

WM-FX451

Adjustment Location :

[MAIN BOARD] (Side A)

L4 : AM Frequency Coverage Adjustment

CT1 : AM Tracking Adjustment

L1 : AM Tracking Adjustmen

L2 : FM Tracking Adjustment

T1 : AM IF Alignment

L3 : FM Frequency Coverage Adjustment

4-1. EXPLANATION OF IC TERMINALS

IC701 µ PD17072GB-540-1A7 (LCD DRIVE, SYSTEM CONTROL)

Pin No. Pin name I/O Description

1 INIT I Key initial terminal. 2 BAND AM O BAND AM ON selection output. 3 BAND FM O BAND FM ON selection output. 4 MEGA BASS I MEGA BASS ON/OFF input (Not used). 5 IF ON O IF ON/OFF control. 6 – Not used (Open). 7 RADIO ON O Radio power ON/OFF control. 8 – Not used (Open).

9 – Not used (Open). 10 KEY IN 1 I Key input. 11 KEY IN 2 I Key input. 12 KEY IN 3 I Key input. 13 KEY IN 4 I Key input. 14 MUTE O Mute signal output. 15 DOLBY O Dolby ON/OFF control (Not used). 16 MODEL I Model select terminal. 17 IF IN I IF signal input. 18 GND – Ground. 19 EO O PLL error output. 20 VCO (AM) I VCO input. 21 VCO (FM/TV) I VCO input. 22 VDD2 – Power supply terminal (+3V). 23 VDD1 – Power supply terminal (+3V). 24 X0 O System clock oscillator (75kHz). 25 X1 I System clock oscillator (75kHz). 26 VDD5 – Power supply (+3V). 27 VDD3 – Power supply (+3V). 28 CAP 1 – Pins connecting capacitors for doubler circuits gemerating the ND drive voltage. 29 CAP 2 – Pins connecting capacitors for doubler circuits gemerating the ND drive voltage. 30 VDD4 – Power supply (+3V).

31 – 34 COM 0 – 3 O ND common output. 35 – 49 LCD 0 – 14 O ND segment drive output.

50 CE I The internal reset circuit functions when low becomes high. 51 TAPE ON I TAPE ON signal input. 52 BEEP O BEEP signal output. 53 KEY OUT 1 O Key scan output. 54 KEY OUT 2 O Key scan output. 55 KEY OUT 3 O Key scan output. 56 KEY OUT 4 O Key scan output.

4-2. BLOCK DIAGRAM

– 9 – – 10 – – 12 –– 11 –

• Signal path.

F :FM E :PB

• Abbreviation FR : French E : Radio section : FM MONO/ST switch 7E : Radio section : DX/LOCAL switch

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