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
M
‘
— 3 —
[ Slider (NR) ]
y
y
y
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
3
Two screws (M1.4 × 2.2)
4
Screw (M1.4 × 1.6)
5
2
Two screws (M1.4 × 2.2)
Case
1
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
4
"Sub Board", "Switch, Leaf",
"Main Board"
Pinch Lever (N)/(R) Assy
Belt (F1), Motor (M601)
Magnetic Head (HP701)
1
Two screws (M1.4 × 2.2)
Screw (M1.4 × 2.2)
2
3-2. CASE
3
— 5 —
3-3. ORNAMENT (OPEN) BLOCK ASSY
s
Release the two claw
1
from the two holes
in the direction allow
2
Claw
Hole
Hole
Ornament (open) block assy
Claw
Mechanism deck block
3-4. “SUB BOARD”, “SWITCH, LEAF”, “MAIN BOARD”
4
Unsolder the 6 places.
qs
Claw
9
Unsolder the
plunger.
0
Unsolder the
flexible board.
qd
MAIN board
2
Screw (M1.4)
1
Screw
7
Screw (M1.4)
5
Screw (M1.4)
6
SUB board
8
Switch leaf
3
Screw (M1.4 × 1.4)
qa
Unsolder the motor.
— 6 —
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