Sony WMEX-621 Service manual

		WM-EX621
	SERVICE MANUAL	AEP Model
	Ver 1.0 2001. 10	UK Model
		E Model
		Chinese Model
		Tourist Model

Manufactured under license from Dolby Laboratories Licensing Corporation.

“DOLBY” and the double-D symbol aare trademarks of Dolby Laboratories Licensing Corporation.

Model Name Using Similar Mechanism	WM-EX610
Tape Transport Mechanism Type	MT-WMEX610-162

SPECIFICATIONS

Frequency response

Playback: 30 - 18 000 Hz

Output

Headphones (ijack) Load impedance 8 - 300 Ω

Power requirements

1.5 V

Rechargeable battery One R6 (size AA) battery

Dimensions (w/h/d)

Approx. 77.1 × 108.0 × 20.5 mm

Mass

Approx. 158 g

Supplied accessories

•Battery case (1)

•Stereo headphones or earphones with remote control (1)

•Battery charger (1)

•Rechargeable battery (NC-6WM, 1.2 V, 600 mAh, Ni-Cd) (1)

•Carrying pouch (1)

•Rechargeable battery carrying case (1)

Design and specifications are subject to change without notice.

CASSETTE PLAYER

9-873-318-01	Sony Corporation
2001J1600-1	Personal Audio Company
© 2001.10	Published by Sony Engineering Corporation

WM-EX621

TABLE OF CONTENTS

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

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

3.DISASSEMBLY

3-1. CASE SUB ASSY ·························································· 7

3-2. MAIN BOARD ······························································· 8

3-3. BELT (F4) ······································································· 8

3-4. MOTOR (CAPSTAN/REEL) (M901) ···························· 9

3-5. LID ASSY, CASSETTE ················································· 9

3-6. ORNAMENT, REEL ···················································· 10

3-7. HOLDER (FS) ASSY ··················································· 10

3-8. LEVER (N)/(R) ASSY, PINCH ···································· 11

3-9. HEAD, MAGNETIC (HP901) ······································ 11

4.MECHANICAL ADJUSTMENT ································ 12

5.ELECTRICAL ADJUSTMENT ·································· 12

6.DIAGRAMS

6-1. BLOCK DIAGRAM ····················································· 13

6-2. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS ·········································· 14

6-3. IC BLOCK DIAGRAMS ·············································· 14 6-4. SCHEMATAC DIAGRAM – MAIN BOARD – ·········· 15 6-5. PRINTED WIRING BOARD – MAIN BOARD – ······ 16 6-6. IC PIN FUNCTION ······················································ 17

7.EXPLODED VIEWS

7-1. CABINET BLOCK ······················································· 19

7-2. MAIN BOARD BLOCK ·············································· 20

7-3. MACHANISM BLOCK – 1 ········································· 21

7-4. MACHANISM BLOCK – 2 ········································· 22

8.ELECTRICAL PARTS LIST ······································· 23

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.

Unleaded solder

Boards requiring use of unleaded solder are printed with the lead free mark (LF) indicating the solder contains no lead.

(Caution: Some printed circuit boards may not come printed with the lead free mark due to their particular size.)

: LEAD FREE MARK

Unleaded solder has the following characteristics.

•Unleaded solder melts at a temperature about 40° C higher than ordinary solder.

Ordinary soldering irons can be used but the iron tip has to be applied to the solder joint for a slightly longer time.

Soldering irons using a temperature regulator should be set to about 350° C.

Caution: The printed pattern (copper foil) may peel away if the heated tip is applied for too long, so be careful!

•Strong viscosity

Unleaded solder is more viscous (sticky, less prone to flow) than ordinary solder so use caution not to let solder bridges occur such as on IC pins, etc.

•Usable with ordinary solder

It is best to use only unleaded solder but unleaded solder may also be added to ordinary solder.

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

WM-EX621

SECTION 1

SERVICE NOTE

[Service Mode]

The service mode enables to operate the mechanism of WM-EX621 while the MAIN board is opened.

Rotation of the idler gear (A) (S side) is detected using the photoreflector (PH701) in the WM-EX621. PH701 is located on the MAIN board, therefore the rotation of the idler gear (A) (S side) cannot be detected by PH701 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 (M901) 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 (S901-1) and the ATS switch (S901-2).

4)Connect an AF oscillator to TP53 (P. IN) and TP14 (GND).

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

2. PRE-SET status

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

1)Check that the slider (NR) is in the center position (S701), 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 (S701) 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 (S701) 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 TP53 (P. IN) and TP14 (GND). (See illustration below)

3)Press the x switch (S702) to enter the STOP mode.

4)Press the AMS switch (S704).

4. PLAY mode

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

2)Connect square wave or sine wave to TP53 (P. IN) and TP14 (GND). (See illustration below)

3)Press the x switch (S702) to enter the stop mode.

4)When the nN switch (S703) 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 (S701) is pressed in the synchronism with the above timing, the machine can enter the PLAY (R side) mode. Press the nN switch (S703) again, and move the FWD/REV switch (S701) 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 2) PRE-SET status.

Note 2: Regarding the nN (S703), x (S702),

AMS (S704) 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 (S701).

TAPE DETECT	ATS
SWITCH	SWITCH
(S901-1)	(S901-2)

	Short
REVIEW	REW
→
AMS	(S704)
CUE
←
FF

Plunger (PM901)

– MAIN BOARD (SIDE B) —

AF OSC

Battery

Square-wave

terminal #

(sine wave) 10 Hz, -3.5 dB

		TP53 (P.IN)
	x(S702)	PH701	Battery terminal
			3
			MM901
		S701
	YREPEAT	FWD ← STOP → REV
	(S703)

TP14

(GND)

3

WM-EX621

[ Slider (NR) ]	[ Tape drive mechanism ]
	Tape drive mechanism in PLAY mode
	Gear (FR)
	(REW:Right side)	Idler Gear (A) (S side)
	Slider (NR)	Gear (REEL) (S side)
		Motor Pulley
	Cam Gear

Gear (Y)

F side R side

Center

Clutch Assy (F)

Pulley (Reverse)

Insert Flywheel (N)

Insert Flywheel (R)

Tape drive mechanism in FF mode

Tape drive mechanism in REW mode

Idler Gear	Gear (FR)
(A) (T side)	(FF:Left side)

Gear (REEL) (T side)

Motor Pulley

Cam Gear

Gear (Y)
Clutch Assy (F)		Pulley (Reverse)
Insert Flywheel (N)	Insert Flywheel (R)

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

	Idler Gear	Idler Gear (A) (S side)
	(A) (T side)
	Gear	Gear (REEL) (S side)
	(REEL) (T side)
		Motor Pulley
	Cam Gear

Gear (Y)

		Clutch Assy (F)	Pulley (Reverse)
	Idler Gear (B)
	Insert Flywheel (N)	Insert Flywheel (R)

4

SECTION 2	WM-EX621
	This section is extracted
GENERAL	from instruction manual.

A C

B

UK, Australian, and	Other models
Hong Kong model

REV

FWD

Plug in firmly.

	HOLD
	VOL
VOL*
HOLD
	REW (–)
Y•REPEAT**	FF (+)
x	SOUND
Swing lever	MODE
	Y•x**
OPEN

*There is a tactile dot beside VOL on the main unit to show the direction to turn up the volume.

**The button has a tactile dot.

5

WM-EX621

Preparations

Prepare a dry battey (not supplied) or the rechargeable battery (supplied).

Dry Battery A

Attach the supplied battery case, and then insert one R6 (size AA) battery with correct polarity.

Note

•For maximum performance we recommend that you use a Sony alkaline battery.

Rechargeable Battery B

1 Insert the supplied rechargeable battery (NC-6WM) into the charger with correct polarity.

2 Plug in the charger to the house current (mains).

UK, Australian, and Hong Kong model: Full charging takes about 3.5 hours.

U.S.A., Canada, European Continent and Saudi Arabian model: Full charging takes about 2.5 hours.

Korean model: The full charging time depends on the voltage of your mains.

110 V: 10 hours

220 V: 2.5 hours

Other models: The full charging time depends on the voltage of your mains.

120 V: 10 hours

220 – 240 V: 2.5 hours

3 Insert the fully charged battery into the rechargeable battery compartment.

You can charge the battery about 300 times.

When to replace/charge the battery C

Replace or charge the battery when “e” flashes in the display on the remote control.

Note

•After the battery is replaced, the setting of the SOUND and MODE buttons will be erased.

Playing a Tape

1Insert a cassette and if the HOLD function is on, slide the HOLD switch in the opposite direction of the arrow to unlock the controls.

2Press Y(play)•x(stop) on the remote control and adjust the volume with VOL. (On the main unit, press Y•REPEAT.)

When adjusting the volume on the main unit

Set the VOL control on the remote control at maximum.

When adjusting the volume on the remote control

Set the VOL control on the main unit to around 6.

Operation on the remote control

To	Press
Switch playback to the	Y•x more than a second
other side	during playback
Stop playback	Y•x once during
	playback
Fast forward*	FF during stop
Rewind*	REW during stop
Play the other side from	FF for 2 seconds or more
the beginning (Skip	during stop
Reverse function)
Play the same side from	REW for 2 seconds or more
the beginning (Rewind	during stop
Auto Play function)
Repeat the current track	Y•x twice during
(Repeat Single Track	playback
function)	To stop a single repeat, press
	Y•x once
Operation on the main unit
To	Do this
Switch playback to the	Press Y•REPEAT during
other side	playback.
Stop playback	Press x.
Fast forward*	Move the swing lever
	toward .FF CUE once
	during stop.
Rewind*	Move the swing lever
	toward REVIEW REW>
	once during stop.
Play the other side from	Move and hold the swing
the beginning	lever toward .FF CUE
(Skip Reverse function)	for 2 seconds or more
	during stop.
Play the same side from	Move and hold the swing
the beginning (Rewind	lever toward REVIEW
Auto Play function)	REW>for 2 seconds or
	more during stop.
Repeat the current track	Press Y•REPEAT for 2
(Repeat Single Track	seconds or more during
function)	playback.
	To stop a single repeat, press it
	again.

*If Y•xon the remote control is pressed during fast forward or rewind, the Walkman switches to playback.

Other tape operations

To play the next track/succeeding 9 tracks from the beginning (AMS*)

On the remote control: Press FF once/repeatedly during playback.

On the main unit: Move the swing lever toward

.FF CUE once/repeatedly during playback.

To play the current track/previous 8 tracks from the beginning (AMS*)

On the remote control: Press REW once/repeatedly during playback.

On the main unit: Move the swing lever toward REVIEW REW>once/repeatedly during playback.

* Automatic Music Sensor

Fast forward/rewind while listening to the sound (CUE/REVIEW)

On the remote control: Press and hold FF/REW during playback and release it at the point you want. On the main unit: Move and hold the swing lever toward .FF CUE/REVIEW REW>during playback and release it at the point you want.

Using Other Functions

Adjusting Playback Mode

You can adjust the playback direction mode (sor d) as well as the BL SKIP mode (on or off).

1 Press MODE repeatedly. With each press the indications change as follows:

Bs v

sBL SKIP v

d v

dBL SKIP

•When “BL SKIP” is displayed, the tape is fastforwarded to the next track if there is a blank space of longer than 12 seconds. You will hear repeated sets of three short beeps when skipping a blank.

•When “s” is displayed, both sides of the tape is played repeatedly.

•When “d” is displayed, both sides of the tape is played once (if you start from R (REV) side, only REV side will be played).

Note

•You cannot adjust the playback mode during fastforward or rewind.

Emphasizing Sound

1 Press SOUND repeatedly. With each press, the indications change as follows:

RV (Sound Revitalizer): emphasizes treble sound MB (Mega Bass): emphasizes bass sound

(moderate effect)

GRV (Groove): emphasizes bass sound (strong effect)

none: normal (no effect)

Notes

•If the sound is distorted with the mode “GRV”, turn down the volume of the main unit or select other modes.

•You cannot change the mode during fast-forward or rewind.

Protecting Your Hearing — AVLS

(Automatic Volume Limiter System)

Hold down MODE until “AVLS” appears in the display.

To cancel the AVLS function, hold down MODE again until “AVLS” disappears.

Note

•You cannot turn on/off the AVLS function during fastforward or rewind.

Locking the Controls

— HOLD Function

Slide the HOLD switch in the direction of the arrow to lock the controls of the Walkman or the remote control.

6

WM-EX621

SECTION 3

DISASSEMBLY

Note : Follow the disassembly procedure as shown in the flow chart below.

Case sub

Set

MAIN board

Belt (F4)

Motor (Capstan/Reel) (M901)

assy

Lid assy,			Ornament,			Holder (FS)
cassette			reel			assy

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

3-1. CASE SUB ASSY

Claw

1 Lid,battery case

2Screw (M1.4 × 2.5)

4 Two screws

(M1.4 × 2.5)

Lever (N)/(R)			Head, magnetic
assy, pinch			(HP901)

S707

3Two screws (M1.4 × 2.5)

Knob (HOLD)

Note : When assembling the case

sub assy,align the Knob (HOLD) with the position of S707.

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

7

WM-EX621

3-2. MAIN BOARD

3 Remove soldering (four points) from the leaf switch.

2Remove soldering (six points) from the head flexible boards.

8MAIN board

Note : Be careful of the claw.

7 Screw

(M1.4)

Claw

4Remove soldering (two points) from plunger solenoid.

S701

6 Two screws

(M1.4)

5Remove soldering (four points) from motor.

1 Shielded sheet

SLIDER

Head flexible board Note : When assembling the MAIN board, align the slider with the position of S701.

3-3. BELT (F4)

2Terminal board (Battery # )

3 Belt (F4)

Belt (F4)

Insert Flywheel

(R)

Motor

Pulley

Pulley (Reverse)

Insert Frywheel (N)

1Remove soldering from the battery terminal board.

8