Sony WMGX-670, WMGX-674 Service manual

WM-GX670/GX674

SERVICE MANUAL

Ver 1.2 2002. 01

Photo: WM-GX670

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

UK Model

Australian Model

WM-GX670

Chinese Model

E Model

WM-GX670/GX674

Model Name Using Similar Mechanism WM-EX677

Tape Transport Mechanism Type MT-WMGX670-162

Radio section

Frequency range FM: 65 – 74/87.5 – 108MHz (Eastern

Europe)

87.5 – 108MHz (other countries)

AM: 530 – 1,710kHz (North, Central,

and South America) 531 – 1,602kHz (other countries)

Tape section

Frequency response (Dolby NR off) Playback: 40 – 15,000Hz

Recording/playback: 100 – 8,000Hz

Output Headphones (2 REMOTE) jack

Load impedance 8 – 300Ω

Input Microphone (MIC) jack

General

Power requirements 1.5V

Rechargeable battery One R6 (size AA) battery

SPECIFICATIONS

Dimensions (w/h/d) Approx. 108.4 × 77.7 × 23.8 mm

(43/8 × 31/8 × 15/16inches), incl. projecting parts and controls

Mass Approx. 250g (8.9oz)

Approx. 315g (11.2oz) incl.

rechargeable battery and a cassette

Supplied accessories Battery case (1)

Stereo earphones with remote control (1) Battery charge (1) AC plug adaptor (1) (except for European, Australian, Saudi Arabian, Chinese, Hong Kong, U.S.A., Canadian, and Korean model) Rechargeable battery (NC-6WM, 1.2V, 600mAh, Ni-Cb) (1) Rechargeable battery carring case (1) Carrying pouch (1) Stereo microphone (1)

Design and specifications are subject to change without notice

9-926-924-12

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 Block Assembly ····················································· 6 3-2. Belt (F2) ·········································································· 7 3-3. Cassette Lid Assembly···················································· 7 3-4. Reel Ornament Assembly ··············································· 8 3-5. Main Board ····································································· 8 3-6. Motor (F2) (M901) ························································· 9 3-7. Holder Assembly····························································· 9 3-8. Pinch Lever (N)/(R) Assembly ····································· 10 3-9. Magnetic Head (HP901) ··············································· 10

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

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

6. DIAGRAMS

6-1. Block Diagram ······························································ 13 6-2. Printed Wiring Board···················································· 16 6-3. Schematic Diagram (1/2) ·············································· 19 6-4. Schematic Diagra (2/2) ················································· 22 6-5. IC Block Diagrams ······················································· 25 6-6. IC Pin Function Discription ·········································· 27

7. EXPLODED VIEWS

7-1. Cabinet Block, Main Board ·········································· 29 7-2. Mechanism Deck Block················································30

8. ELECTRICAL PARTS LIST ······································· 31

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 —

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.

SECTION 1

SERVISE NOTE

[Service Mode]

The service mode enables to operate the mechanism of WM-GX670/ GX674 while the MAIN board is opened. Rotation of the idler gear (A) (S side) is detected using the photoreflector (PH1) in the WM-GX670/GX674. 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 po wer 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 AMS switch (S4) and the REW AMS 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 (N/R) 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 AMS (S4), and REW AMS (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)

REW AMS

(S5)

(S3)

REC

(S11)

FF AMS

(S4)

p



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

— 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

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

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

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

Insert Flywheel (R)

Gear

(REEL)(S side)

Motor Pulley

Pulley (Reverse)

— 4 —

• LOCATION OF CONTROLS

SECTION 2

GENERAL

123 45

!¶

!§

!∞

• LOCATION OF REMOTE CONTROL

(WM-GX670 model)

1 2 REMOTE jack

2 REW, AMS button 3 “ ”, REPEAT button 4 FF , AMS button 5 OPEN knob 6 Battery case 7 Display window

7 8

8 HOLD c knob 9 SET button !º MENU button !¡ BAND, PADIO ON button !™ ENTER, COUNTER RESET button !£ REC button !¢ p, RADIO OFF button !∞ ∑ VOL knob !§ ISS (1, 2, 3) knob

9!º!¡!™!£!¢

!¶ MIC (PLUG IN POWER) jack

• LOCATION OF REMOTE CONTROL

(WM-GX674 model)



1 FF, PRESET+ button 2 “ ” • p, RADIO ON/BAND OFF button 3 HOLD knob 4 REW, PRESET– button 5 VOL knob

1 HOLD button 2 DISPLAY window 3 MENU button 4 JOG lever 5 REC button 6 VOL knob

— 5 —

DISASSEMBLY

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

SECTION 3

Set

Case block assembly

Belt (F2)

Cassette lid assembly Main board

Motor (F2) (M901)

Holder assembly

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

3-1. CASE BLOCK ASSEMBLY

S11

S501

knob (ISS)

Note:

When assembling the case block assembly, align the knob (ISS) with the position of S501.

Reel ornament assembly

Pinch lever (N/R) assembly

Magnetic head (HP901)

Claw

Battery case Lid

knob (REC)

Note:

When assembling the case block assembly, align the knob (REC) with the position of S11.

T wo screws

(M1.4

2.5)

Remove the case block assembly

in the direction of the arrow.

Screw (M1.4 × 2.5)

knob (HOLD)

Note:

When assembling the case block assembly, align the knob (HOLD) with the position of S2.

T wo screws

(M1.4

2.5)

— 6 —

3-2. BELT (F2)

Belt (F2)

T erminal boar

(Battery ’)

Remove solder from

the battery terminal board.

3-3. CASSETTE LID ASSEMBLY

Cassette lid assembly

Shaft

Two screws (M1.4 × 2.0)

Screw (M1.4 × 2.0)

Open the cassette lid

— 7 —

3-4. REEL ORNAMENT ASSEMBLY

Reel Ornament assembly

Note:

Remove the assembly while removin the three claws and boss carefully.

Claw

3-5. MAIN BOARD

Screw (M1.4)

Head flexible board

Remove soldeing (two points) from plunger solenoid.

Screw (B1.7 × 3)

tapping

Screw (M1.4)

Screw (B1.7 × 3)

tapping

Screw (B1.4 × 1.6)

Remove soldeing (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 (F2) (M901)

Two screw (M1.4)

Motor (F2) (M901)

Toothed lock

3-7. HOLDER ASSEMBLY

Lock lever (S)

Flexible board

Screw (M1.4)

Cassette bracket assembly

Shaft

Remove the holder assembly in the directio of the arrow.

Shaft

Lock lever (B)

— 9 —

Two screws (M1.4 × 1.4)

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