Sony WMGX-888 Service manual

WM-GX680/GX688

SERVICE MANUAL

Ver 1.2 2002. 01

Photo: WM-GX688

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

US Model

AEP Model

WM-GX680

E Model

Tourist Model

WM-GX688

Chinese Model

WM-GX680/GX688

Model Name Using Similar Mechanism WM-GX677

Tape Transport Mechanism Type MF-WMGX670-162

SPECIFICATIONS

Radio section

Frequency range

FM : 76.0 ~ 90.0 MHz (Tourist Model)

: 87.5 ~ 108 MHz (Other Models)

AM : 531 ~ 1710 kHz (Tourist, US Models)

: 531 ~ 1 602 kHz (Other Models)

Tape section

Frequency response (Dolby NR off)

Playback: 40 - 15 000 Hz Recording/playback: 100 - 8 000 Hz

Output

Headphones (iREMOTE) jack Load impedance 8 - 300 Ω

Input

Microphone (MIC) jack

General

Power requirements

1.5 V Rechargeable battery One R6 (size AA) battery

Dimensions (w/h/d)

Approx. 108.4 × 77.7 × 23.0 mm

⁄8 × 31⁄8 × 29⁄32 inches)

Mass

Approx. 148 g (5.3 oz)

Supplied accessories

Battery case (1) Stereo headphones or earphones with

remote control (1) Battery charger (1) AC plug adaptor (1) (Saudi Arabian,

Tourist model) Rechargeable battery (NC-6WM, 1.2 V,

600 mAh, Ni-Cd) (1) Rechargeable battery carrying case (1) Carrying pouch (1) Stereo microphone (1)

Design and specifications are subject to change without notice.

9-873-034-12

2002A1600-1

RADIO CASSETTE-CORDER

Sony Corporation

Personal Audio Company

Published by Sony Engineering Corporation

TABLE OF CONTENTS

1. SERVICE NOTE ······························································· 3

2. GENERAL ··········································································5

3. DISASSEMBLY

3-1. Case assy·········································································6 3-2. Belt··················································································7 3-3. Lid block assy, cassette ··················································· 7 3-4. Ornament, reel ································································ 8 3-5. Main Board ·····································································8 3-6. Motor (M601) ·································································9 3-7. Holder (F) Assy······························································· 9 3-8. Lever (N)/(R) Assy, pinch ············································· 10 3-9. Head, magnetic (HP901)··············································· 10

4. MECHANICAL ADJUSTMENT ································ 11

5. ELECTRICAL ADJUSTMENT ·································· 11

6. DIAGRAMS

6-1. Block Diagram ······························································ 13 6-2. Schematic Diagram (1/3) ·············································· 16 6-3. Schematic Diagram (2/3) ·············································· 19 6-4. Schematic Diagram (3/3) ·············································· 21 6-5. IC Block Diagrams ·······················································23 6-6. Printed Wiring Board (SIDE A)···································· 25 6-7. Printed Wiring Board (SIDE B) ···································· 27 6-8. IC Pin Function Discription ·········································· 29

7. EXPLODED VIEWS

7-1. Cabinet Block, Main Board ··········································31 7-2. Mechanism Deck Block················································ 32

8. ELECTRICAL PARTS LIST ······································· 33

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.

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.

— 2 —

SECTION 1

SERVICE NOTE

[Service Mode]

The service mode enables to operate the mechanism of WM-GX680/ 688 while the MAIN board is opened. Rotation of the idler gear (A) (S side) is detected using the photoreflector (PH1) in the WM-GX680/688. PH1 is located on the MAIN board, therefore the rotation of the idler gear (A) (S side) cannot be detected by PH1 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. DISASSEMBL Y”. Open the MAIN board.

2) Connect the motor (M601) and the plunger solenoid (PM901) 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 DETECT switch (S901-2), R TUME switch (S901-1), F TUME switch (S902-1) and ATS switch (S902-2).

4) Connect an AF oscillator to resistor (R43).

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

2. PRE-SET status

The PLA Y, FF and REW modes can be entered only from the PRESET status.

1) Check that the slider (NR) is in the center position (S1), and the FWD/REV switch is also in the center position. When these switches are not in the center position, set them to the PRE-SET status as follows.

2) Move the FWD/REV switch (S1) to the same position as the slider (NR) is set.

3) The slider (NR) can be moved when the main power of the regulated power supply is turned OFF once then back ON. Move the FWD/REV switch (S1) to the center position in synchronism with the timing when the slider (NR) is moved.

3. FF, REW modes

1) Check that the PRE-SET status is set.

2) Connect square wave or sine wave to resistor (R43). (See illustration below.)

3) Press the p switch (S3) to enter the STOP mode.

4) Press the FF PRESET+ switch (S4) and the REW PRESET– switch (S5).

4. PLAY mode

1) Check that the PRE-SET status is set.

2) Connect square wave or sine wave to resistor (R43). (See illustration below.)

3) Press the p switch (S3) to enter the STOP mode.

4) When the 9(REPEAT switch (S9) of the MAIN board is pressed, the slider (NR) moves once to the F side then moves to the R side. When the FWD/REV switch (S1) is pressed in the synchronism with the above timing, the machine can enter the PLAY (R side) mode. Press the 9(REPEAT switch (S9) again, and move the FWD/REV switch (S1) in the synchronism with the motion of slider (NR). It enables the machine to enter into the PLAY (F side) mode.

Note 1: When you fail to enter the PLAY mode, re-start from step

1) PRE-SET status.

Note 2: Regarding the 9(REPEAT (S9), p (S3),

FF PRESET+ (S4), and REW PRESET– (S5) switches, use these switches of the remote control unit as much as possible.

Note 3: If a headphones are used, the beep sound shows the timing

of the FWD/REV switch (S1).

R TUME SWITCH (S901-1)

Short

TAPE DETECT

SWITCH (S901-2)

FF PRESET +

(S4)

REW PRESET –

(S5)

(S3)

REPEAT

(S9)

ENTER

(S10)

– MAIN BOARD (SIDE B) —

Plunger (PM901)

R43

Square wave

10 Hz, -3.5 dB

(SIDE A)

Battery terminal

BAND

(S8)

’

(SIDE A)

AF OSC

(sine wave)

Q15

(S6)

FWD

←

ATS SWITCH (S902-2)

SET (S7)

(S1)

STOP→REV

F TUME SWITCH (S902-1)

Battery terminal

Short

‘

M601

REC

(S11)

— 3 —

[ Slider (NR) ] [ Tape drive mechanism ]

Tape drive mechanism in PLAY mode

Gear (NR)

(FWD : Left side

REV : Right side)

Idler Gear

(A)(T side)

Gear

Idler Gear(B)

F side

Center

Slider (NR)

(REEL)(T side)

Cam Gear

R side

Gear (Y)

Insert Flywheel (N)

Idler Gear (A)(S side)

Gear (REEL)(S side)

Motor Pulley

Clutch Assy(F)

Pulley (Reverse)

Insert Flywheel (R)

Tape drive mechanism in FF mode

Idler Gear (A)(T side)

Gear

(REEL)(T side)

Cam Gear

Gear (Y)

Insert Flywheel (N)

Gear (FR)

(FF : Left side)

Insert Flywheel (R)

Clutch Assy(F)

Pulley (Reverse)

Motor Pulle

Tape drive mechanism in REW mode

Gear (FR)

(REW : Right side)

Cam Gear

Gear (Y)

Insert Flywheel (N)

Idler Gear (A)(S side)

Clutch Assy(F)

Insert Flywheel (R)

Gear

(REEL)(S side)

Motor Pulley

Pulley (Reverse)

— 4 —

• LOCATION OF CONTROLS

REW (AMS)

FF (AMS)

SECTION 2

GENERAL

This section is extracted from instruction manual.

Y•REPEAT

iREMOTE

VOL

TUNE/PRESET +

TUNE/PRESET – RADIO ON/BAND

RADIO OFF

Y•x

VOL

Plug in firmly.

HOLD

FF REW

RADIO ON/ BAND•OFF

ENTER

ENTER/COUNTER RESET

SET

SETMENU

PB TUNE FM PB

SOUND MODE MODE AVLS MODEaNR

Tape counter

HOLD

PRESET +

PRESET –

HOLD

— 5 —

DISASSEMBLY

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

SECTION 3

Set Case assy

Belt

Lid block assy, cassette Main board

Motor (M601)

Holder (F) assy

Lever (N)/(R) assy, pinch

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

3-1. CASE ASSY

S11

S501

knob (ISS)

Note: When assembling the

case assy, align the knob (ISS) with the position of S501.

Ornament, reel

Head, magnetic (HP901)

Claw

1 Lid, Battery

knob (REC)

Note: When assembling the

case assy, align the knob (REC) with the position of S11.

4 Two screws (M1.4 × 2.5)

2 Two screws (M1.4 × 2.0)

5 Remove the case assy in the direction of the arrow.

3 Screw (M1.4 × 2.0)

knob (HOLD-B)

Note: When assembling the

case assy, align the knob (HOLD-B) with the position of S2.

— 6 —

3-2. BELT

Belt threading

Belt

3 Belt

2 Terminal boar

(Battery ’)

1 Remove solder from the battery terminal board.

3-3. LID BLOCK ASSY, CASSETTE

5 Lid block assy, cassette

4 Shaft

2 Two screws (M1.4 × 2.0)

1 Screw (M1.4 × 2.0)

3 Open the cassette lid

— 7 —

3-4. ORNAMENT, REEL

1 Ornament, reel

Remove the assembly while removin

Note:

the three claws and boss carefully.

Claw

3-5. MAIN BOARD

Screw (M1.4)

Toothed lock

Ats flexible board

Remove soldering (two points) from plunger solenoid.

Screw (B1.7 × 3)

tapping

Screw (M1.4)

Screw (B1.7 × 3)

tapping

Screw (1.4 × 1.6)

Remove soldering (four points) from motor.

Screw (M1.4)

— 8 —

SLIDER

Note:

When assembling the MAIN board, align the slider with the position of S1.

3-6. MOTOR (M601)

1 Two screws (M1.4) Toothed lock

2 Motor (M601)

3-7. HOLDER (F) ASSY

5 Lever (S), lock

8 Flexible board

4 Screw (M1.4)

7 Bracket (cassette) assy

2 Shaft

9 Remove the holder (F)

assy in the direction of the arrow.

6 Shaft

3 Lever (B), lock

— 9 —

1 Two screws (M1.4 × 1.6)

3-8. LEVER (N) / (R) ASSY, PINCH

Claw

2 Remove the lever (N) assy, pinch in the direction of the arrow.

Note: Be careful of the claw

Claw

1 Remove the lever (R) assy, pinch in the direction of the arrow.

Note: Be careful of the claw

3-9. HEAD, MAGNETIC (HP901)

1 Two screws (M1.4 × 7.2)

2 Remove the head, magnetic (HP901) in the direction of the arrow.

— 10 —

+ 22 hidden pages