Sony WMGX-612, WMGX-614 Service manual

WM-GX612/GX614

SERVICE MANUAL

Ver 1.1 2002. 01

Photo : WM-GX614

SPECIFICATIONS

AEP Model

UK Model

E Model

Australian Model

Model Name Using Similar Mechanism NEW

Tape Transport Mechanism Type MF-WMGX614-112

9-960-414-12

2002A1600-1

RADIO CASSETTE CODER

Sony Corporation

Personal Audio Company

Published by Sony Engineering Corporation

— 1 —

TABLE OF CONTENTS

Section Title Page

SECTION 1. SERVICE NOTE ................................. 3

SECTION 2. GENERAL .......................................... 5

SECTION 3. DISASSEMBLY

3-1. Cassette Lid ASSY and Case ASSY ................................. 7

3-2. Bracket ASSY and Cassette Holder ASSY ....................... 7

3-3. Tuner Board ....................................................................... 8

3-4. Main Board.........................................................................8

SECTION 4. MECHANICAL ADJUSTMENT .......... 9

SECTION 5. ELECTRICAL ADJUSTMENT ........... 9

SECTION 6. DIAGRAMS

6-1. IC Pin Functions

IC501 BA3641FV REC AMP ......................................... 11

IC701 MSM63120B System Control .............................. 11

IC702 SMC62L3A LCD Drive ....................................... 13

6-2. Printed Wiring Board — Tuner Section —.....................14

6-3. Schematic Diagram — Tuner Section —........................ 17

6-4. Schematic Diagram — Main Section — ......................... 21

6-5. Printed Wiring Board — Main Section —...................... 25

6-6. IC Block Diagrams .......................................................... 29

SECTION 7. EXPLODED VIEWS

7-1. Case Section ..................................................................... 33

7-2. Main Board Section ......................................................... 34

7-3. Mechanism Section (MF-WMGX614-112)..................... 35

SECTION 8. ELECTRICAL PARTS LIST............. 36

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 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 solder-

ing or unsoldering.

SAFETY-RELATED COMPONENT WARNING !!

COMPONENTS IDENTIFIED BY MARK ! OR DOTTED 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.

— 2 —

SECTION 1

SERVICE NOTE

[Service Mode]

Mode which enables the mechanism to be operated with the MAIN board opened. Photo sensor PH701 mounted on the MAIN board is used to detect rotaion of the reels. Because it is mounted on the MAIN board, when the MAIN board is being removed, rotation of the reels cannot be detected and the auto-off/tape-end detector circuit does not operate correctly. F/R switch (S701) is also mounted on the MAIN board. Therefore, without the MAIN board, the head cannnot be placed in playback position, and power cannot be supplied to the circuitry of the playback system. When the MAIN board is being removed, follow the procedures below, in order to check operation of the mechanisms of the tape deck and to check voltages supplied to each circuit.

1. Setting

1) Refer to “Disassembly” and remove the cabinet and open the MAIN board.

2) Connect the MAIN board to the motor and plunger using a jumper wire. Use “Extension tool (1-769-143-11)) (one set 10 tools)” to make connection simple.

3) Short-circuit the service mode land (BP2) by soldering.

4) Apply a square wave signal to TP20. (See the figure on the right.)

5) Supply 1.5V to the battery terminals (+) and (–) using a DC power supply.

[MAIN Board]

— Side A —

AF OSCILLATOR

Connect to plunger

S713 (ENTER)

S712 (TUNING –)

S704 S711 (TUNING +)

S707 (RADIO ON BAND)

— Side B —

(REPEAT œ)

Battery Terminal (–)

S703 (RADIO OFF p)

SQUARE WAVE (SINE WAVE) 10Hz

3.5 dB (1.5V)

S709 (SET)

Service mode land

S710 (MENU)

S705 (AMS FF PRESET +)

S706 (AMS REW PRESET –)

TP20

Battery Terminal (+)

Connect to motor

2. Preset State This state must be set to set the PLAY, FF, and REW modes.

1) Check that the lever (FR SW) is at the center and F/R switch (S701) is at the center. If not, set the preset state as follows.

2) Move the F/R switch (S701) according to the side faced by the lever (FR SW).

3) Turn OFF the DC power supply switch once and then turn it ON again so that the lever (FR SW) can be moved. Move the F/R switch (S701) according to this timing and set to the center.

3. FF REW Mode

1) Set the preset state and press the FF switch and REW switch.

4. PLAY Mode

1) Set the preset state.

2) Press the ~ switch. The lever (FR SW) will move to the F side once and then to the R side. Move the F/R switch (S701) according to this timing to set the PLAY (R side) mode. Press the ~ switch another time and move the F/R switch (S701) according to the movement of the lever (FR SW) to set the PLAY (F side) mode.

Note 1 : If the above cannot be performed, start again from

preset.

Note 2 : Use the remote control ~, &, FF, and REW switches

as much as possible. If the remote control is not available, do not touch S703 to S706 with the hand and use something with a round tip to press them.

R side

[Lever (FR SW)]

PH701

S701 F/R SWITCH (FWD n STOP n REV)

F side

Center

R side

Lever (FR SW)

S702

(HOLDER

SWITCH)

S714 (C HOLD)

Center

F side

— 3 —

[Rotation system]

Rotation system during PLAY.

Reel table (T side)

Gear (A)

Gear (K)

Capstan wheel (N) assembly

Clutch assembly

Gear (B)

Gear (C)

Gear (NR) (REV : Left side/ FWD : Right side)

Capstan wheel (R) assembly

Reel table (S side)

Motor pully

Pulley (REVERSE)

Rotation system during REW.

Gear (B)

Reel table (T side)

Gear (K)

Capstan wheel (N) assembly

Gear (NR) (REW : Left side)

Gear (NR)

Gear (A)

Capstan wheel (R) assembly

Motor pully

Clutch assembly

Pulley (REVERSE)

Rotation system during FF.

Gear (FR)

Clutch assembly

Gear (K)

Capstan wheel (N) assembly

(FF : Right side)

Gear (NR)

Reel table (S side)

Gear (C)

Capstan wheel (R) assembly

Motor pully

Pulley (REVERSE)

— 4 —

FUNCTION OF CONTROL

SECTION 2

GENERAL

!∞

!¢

!™!£

!¡

!§

1Display Window 2PRESET +/AMS FF button 3PRESET –/AMS REW button 4MENU button 5BATT indicater 6SET button 7p/RADIO OFF button 8ENTER button 92/REMOTE jack

• ILLUST LATION : WM-GX614 MODEL

!•

!¶

0HOLD knob !¡VOLUME knob !™RADIO ON/BAND button !£TUNIG + button !¢TUNIG – button !∞œ/REPEAT button !§REC switch !¶ISS switch !•MIC jack

— 5 —

This section is extracted from instruction manual.

— 6 —

SECTION 3

DISASSEMBLY

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

3-1. CASSETTE LID ASSY AND CASE ASSY

Two screws (M1.4x2)

Cassette lid ASSY

Mechanism Block

TU flexible board

Reel ornament ASSY

Screw (M1.4x3)

Two screws (M1.4x3)

3-2. BRACKET ASSY AND CASSETTE HOLDER ASSY

Screw (M1.4)

Bracket ASSY

Case ASSY

Lock lever (B)

Note : Adjust the knob and the switch

position when installing.

Two screws (M1.4x2)

Screw (M1.4)

— 7 —

Cassette holder ASSY

3-3. TUNER BOARD

TUNER board

Three tapping screws

Case ASSY

TU cover

Note for installation

3-4. MAIN BOARD

Remove the Main board direction of arrow.

Flexible board (Head)

Remove the solder of the ATS flexible board.

Remove the solder of the plunger solenoid.

Screw (M1.4x2)

Tapping screw

Remove the solder of the motor.

Tapping screw

S701

Lever (FR switch)

Note : Confirm if the switch lever

installs it self in the groove of a lever (FR switch) for assembling.

— 8 —

SECTION 4

SECTION 5

MECHANICAL ADJUSTMENT

PRECAUTION

1. Before adjusting, clean the following parts with a piece of cotton moistened with alcohol.

playback head pinch roller rubber belt capstan

2. Demagnetize the playback head using a head 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]

Mode

FWD

FWD Back tension

REV

REV Back tension

REW

Torque Meter Meter Reading

18 — 33 g • cm

CQ-102C

0.5 — 3.0 g • cm

18 — 33 g • cm

CQ-102RC

0.5 — 3 g • cm

CQ-201B

More than 40 g • cm

ELECTRICAL ADJUSTMENT

PRECAUTION

1. Specified voltage : 1.3V.

2. Switch position DOLBY NR switch : OFF MEGA BASS switch: NORM AVLS : OFF

CASSETTE SECTION

Test tape

Type

[Tape Speed Adjustment]

Procedure :

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

1. Playback WS-48A (tape center part) in the FWD state and adjust RV601 so that the frequency counter reading becomes 3000 ± 10 Hz.

2. Playback WS-48A (tape center) in the REV state. Check that the frequency counter reading is within 2.5% of the reading of step 1.

Signal Used for

Tape Speed AdjustmentWS-48A

frequency counter

3 kHz, 0 dB

set

PHONES jack

Adjustment Point :

[MAIN BOARD] — Component side —

S714

(HOLD)

RV601

IC601

— 9 —

TUNER SECTION

[AM]

BAND switch : AM

NOTE: The adjustment should be performed setting the area indication

to “Eur”. (Refer to “Receiving Stations Outside Your Country” on page 6.) After the adjustment, reset the area indication as it was.

AM RF SSG

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

Put the lead-wire antenna close to the set.

[FM]

BAND switch : FM

FM RF SSG

0.01µF

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

to ANT (TP1)

VTVM

[FM VCO Adjustment]

Procedure :

FM RF SSG

0.01µF

Carrier frequency : 98MHz Modulation : no modulation output level : 0.1V (100dB)

to ANT (TP1)

1. Connect frequency counter to the positions shown below.

2. Tune the to 98 MHz.

3. Adjust RV1 for 19 kHz ± 100Hz reading on the frequency counter.

frequency counter

TP23

(IC2 Pin !™)

IC2 Pin 9

1µF

100k

• Adjustment Parts Location

[TUNER BOARD] — Component side —

set

PHONES

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

AM IF ADJUSTMENT

Adjust for a maximum reading on VTVM.

T2 450 kHz

AM VT VOLTAGE ADJUSTMENT

1.5 V

T1 531 kHz

AM TRACKING ADJUSTMENT

Adjust for a maximum reading on VTVM.

CT1

FM IF ADJUSTMENT

Adjust for a maximum reading on VTVM.

L3 10.7 MHz

621 kHz

1,395 kHz

TP23

RV1 : VCO

T2 : AM IF

T1 : AM VT

L3 : FM IF

TP1

CT1 : AM TRACKING

L5 : AM TRACKING

— 10 —

+ 22 hidden pages