Sony WMEX-20 Service manual

WM-EX20

SERVICE MANUAL

Ver 1.0 1999. 08

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

SPECIFICATIONS

US Model

Canadian Model

AEP Model

UK Model

E Model

Australian Model

Tourist Model

Model Name Using Similar Mechanism NEW T ape Transport Mechanism T ype MT -WMEX20-162

Tape section

Frequency response (Dolby NR off) Playback: 30 – 18,000 Hz Output Headphones (REMOTE 2 jack)

Load impedance 8 – 300 Ω

General

Power requirements 1.5 V

One rechargeable battery or one R6 (size AA) battery

Dimensions (w/h/d) Approx. 78.7 × 108.6 × 18.7 mm

(31/8 × 43/8 × 3/4 inches), incl. projecting parts and controls

Mass Approx. 180 g (6.4 oz)

Approx. 240 g (8.5 oz) (incl. rechargeable battery and a cassette)

Supplied accessories Battery case (1)

Stereo earphones with remote control (1) Battery charger (1)

US, CND model : BC-7DC AEP, FR model : BC-7DY E, JE model : BC-7HT UK model : BC-7S AUS model : BC-7SG KR model : BC-9HR

Rechargeable battery (1)

US, CND, AEP, UK, FR, AUS model : NC-6WM, 1.2V, 600mAh, Ni-Cd KR, E, JE model:

NH-14WM, 1.2V, 1400mAh, Ni-MH Rechargeable battery carrying case (1) Carrying pouch (1) E, JE, model:

AC plug adaptor (1)

Design and specifications are subject to change without notice

• Abbreviation CND : Canadian model FR : French model AUS : Australian model KR : Korea model JE : Tourist model

MICROFILM

CASSETTE PLAYER

TABLE OF CONTENTS

1. GENERAL ·········································································· 2

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

3. DISASSEMBLY

3-1. Lid Assy, Cassette ···························································5 3-2. Case·················································································5 3-3. Ornament (Open) Block Assy········································· 6 3-4. “Sub Board”, “Switch, Leaf”, “Main Board” ················· 6 3-5. Belt (F KAI), Motor (M601)··········································· 7 3-6. Holder Assy····································································· 7 3-7. Pinch Lever (N)/(R) Assy ···············································8 3-8. Magnetic Head (HP701) ················································· 8

4. MECHANICAL ADJUSTMENT ·································· 9

5. ELECTRICAL ADJUSTMENT ···································· 9

SECTION 1

GENERAL

This section is extracted from instruction manual.

6. DIAGRAMS

6-1. Block Diagram ······························································ 10 6-2. Printed Wiring Board ···················································· 12 6-3. Schematic Diagram (1/2) ·············································· 15 6-4. Schematic Diagra (2/2) ················································· 18 6-5. IC Block Diagrams ······················································· 21 6-6. IC Pin Function Discription ·········································· 23

7. EXPLODED VIEWS

7-1. Cabinet Block, Main Board ·········································· 25 7-2. Mechanism Deck Block ················································ 26

8. ELECTRICAL PARTS LIST·······································27

1 ∑ VOL knob 2 2 REMOTE jack 3 Operation button 4 HOLD/OPERATION knob 5 OPEN knob 6 Dry battery case contact 7 Rechargeable battery compartment

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.

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK ! OR DO TTED LINE WITH MARK ! ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.

8 Headphones plug 9 DISPLA Y window 0 SOUND button !¡ MODE button !™ HOLD button !£ 9((PLAY), p(STOP), button !¢ FF button !∞ REW button !§ VOL knob

ATTENTION AU COMPOSANT AYANT RAPPORT

À LA SÉCURITÉ! LES COMPOSANTS IDENTIFÉS P AR UNE MARQUE ! SUR LES DIAGRAMMES SCHÉMA TIQUES ET LA LISTE DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.

— 2 —

SECTION 2

SERVICE NOTE

[Service Mode]

The service mode enables to operate the mechanism of WM-EX20 while the MAIN board is opened. Rotation of the idler gear (A) (S side) is detected using the photoreflector (PH702) in the WM-EX20. PH702 is located on the MAIN board, therefore the rotation of the idler gear (A) (S side) cannot be detected by PH702 when the MAIN board is removed. As a result, the motor cannot be controlled and cannot run correctly. To repair the machine after the MAIN board is removed while the main power is turned on, follow the procedures as described below.

1. Setting

1) Remove the cabinets referring to section “3. DISASSEMBLY”. Open the MAIN board.

2) Connect the motor (M601) and the plunger solenoid (PM701) to the MAIN board using the jumper wires. When the extension jig (1-769-143-11) (10 wires as a set) is used, they can be connected easily.

3) Short the TAPE IN switch land (BP1) with solder. Input a square (or sine) wave of 10 Hz (at 1.3 Vp-p) to both PH IN T land (TP37) and PH IN S land (TP36) with jumper wire.

4) Connect DC 1.3 V from e xternal regulated power supply to ‘ and ’ terminals of the battery.

2. PRE-SET status

The set must be in this state before the PLAY , FF and REW modes can be entered.

1) Make sure that the slider (F/R) is in the center position and that the F/R switch (S702) is in the center position. Make sure that the reel gear does not rotate by rotating the flywheel on the F side clockwise. If improper, place the set in the preset state according to the following instructions:

2) Repeat the step below some times to ensure the above conditions.

* Pull away the trigger level from the plunger with tweezers or

other means. Then rotate the flywheel on the F side clockwise.

3) Turn the stabilized power supply OFF once and then ON.

3. FF, REW modes

1) Check for “2. Preset state” and push the FF switch and the REW switch.

2) Move the F/R switch (S702) to the movement of the slider to enter the FF/REW mode.

4. PLAY mode

1) Check for “2. Preset state”.

2) Push the 9( switch on the remote commander to mov e the lever (SW) toward the R side . W ith timing to this, mo v e the F/ R switch (S702) to enter the PLAY (R side) mode.

Note 1: If failed, retry from the preset state. Note 2: The 9(, p, FF, and REW switches on the remote

commander should be used whenever possible.

– MAIN BOARD (SIDE B) —

TAPE IN SWITCH (S704-1)

SWITCH (S704-2)

BP1

ATS

Plunger (PM701)

Battery terminal

’

jumper

AF OSC

Square wave

(sine wave)

10 Hz, -3.5 dBs

S PH IN(S)(TP36) T PH IN(S)(TP37)

GND

(S702)

FWD

←

CNT→REV

Battery terminal

M601

‘

— 3 —

[ Slider (NR) ]

F side flywheel

slider (NR)

F side

center

R side

[ Rotational system ]

1. Rotational System of PLAY Mode

gear (reel) (T side)

idler gear (A) (T side)

gear (Y)

insert flywheel (N)

idler gear (A) (S side)

gear (NR)

FWD

REV

idler gear (B)

insert flywheel (R)

clutch assy (F)

gear (reel) (S side)

motor pulle

reverse pulley

2. Rotational System of FF Mode

gear (reel) (T side)

idler gear (A) (T side)

gear (FR)

gear (Y)

insert flywheel (N)

clutch assy (F)

insert flywheel (R)

motor pulle

reverse pulley

3. Rotational System of REW Mode

idler gear (A) (S side)

gear (reel) (S side)

clutch assy (F)

gear (Y)

insert flywheel (N)

gear (FR)

insert flywheel (R)

motor pulle

reverse pulley

— 4 —

SECTION 3

Mechanism deck block

Two screws (M1.4 × 2.2)

Screw (M1.4 × 1.6)

Two screws (M1.4 × 2.2)

Case

Lid, battery case

DISASSEMBLY

• The equipment can be removed using the following procedure.

Lid Assy, Cassette

Set

Case

Ornament (OPEN) Block Assy

Holder Assy

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

3-1. LID ASSY, CASSETTE

Lid assy, cassette

"Sub Board", "Switch, Leaf", "Main Board"

Pinch Lever (N)/(R) Assy

Belt (F1), Motor (M601)

Magnetic Head (HP701)

Two screws (M1.4 × 2.2)

Screw (M1.4 × 2.2)

3-2. CASE

— 5 —

3-3. ORNAMENT (OPEN) BLOCK ASSY

Release the two claw

from the two holes

in the direction allow

Claw

Hole

Ornament (open) block assy

Claw

Mechanism deck block

3-4. “SUB BOARD”, “SWITCH, LEAF”, “MAIN BOARD”

Unsolder the 6 places.

Claw

Unsolder the

plunger.

Unsolder the

flexible board.

MAIN board

Screw (M1.4)

Screw

Screw (M1.4)

SUB board

Switch leaf

Screw (M1.4 × 1.4)

Unsolder the motor.

— 6 —

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