Sony Walkman WM-EX402 User manual

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Model Name Using Similar Mechanism NEW
Tape Transport Mechanism Type MF-WMFX483-147
SERVICE MANUAL
AEP Model
E Model
WM-EX402/EX404/EX405/EX406
CASSETTE PLAYER
MICROFILM
Photo : WM-EX404
Tape section
Frequency response (Dolby NR off)
Playback: 40 - 14,000 Hz
Output Headphones 2jack
Load impedance 8 - 300 ohms
General
Power requirements 3 V
Two R6 (size AA) batteries
(negative ground)
Dimensions (w/h/d) Approx. 115.5 ×83.5 ×32.5 mm
(4 5/8 ×3 3/8 ×1 5/16 inches) incl.
projecting parts and controls
Mass Approx. 135 g (4.8 oz) / Approx.
215 g (7.6 oz) incl. batteries and
a cassette
Supplied accessories Stereo headphones or Stereo
earphones with remote
control (1) (EX406 only)
Stereo headphones or Stereo
earphones (1) (EX402/EX404/
EX405 only)
Belt clip (1)
Design and specifications are subject to change without
notice.
SPECIFICATIONS
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 soldering
or unsoldering.
Notes on Chip Component Replacement
•Never reuse a disconnected chip component.
•Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
DolbynoisereductionmanufacturedunderlicensefromDolbyLabo-
ratories Licensing Corporation.
“DOLBY” and the double-D symbol aare trademarks of Dolby
Laboratories Licensing Corporation.

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TABLE OF CONTENTS
1. GENERAL
Getting Started ........................................................................ 4
Operating the Walkman .......................................................... 4
Additional Information ........................................................... 4
2. DISASSEMBLY
2-1. Cabinet (Rear) Assy ............................................................ 5
2-2. Main Board ......................................................................... 6
2-3. Mechanism Deck................................................................. 6
2-4. Cassette Lid Sub Assy ......................................................... 7
2-5. Display Board ..................................................................... 7
3. MECHANICAL ADJUSTMENTS..............................8
4. ELECTRICAL ADJUSTMENTS ...............................8
5. DIAGRAMS
5-1. Printed Wiring Boards ......................................................... 9
5-2. Schematic Diagram ........................................................... 11
6. EXPLODED VIEWS
6-1. Cassette Lid Section .......................................................... 16
6-2. Cabinet Section ................................................................. 17
6-3. Mechanism Deck Section.................................................. 18
7. ELECTRICAL PARTS LIST ....................................19

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SECTION 1
GENERAL This section extracted from
instruction manual.

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SECTION 2
DISASSEMBLY
•The equipment can be removed using the following procedure.
Set /Cabinet (rear) assy Main board /Mechanism deck
Cassette lid sub assy /Display board
Note : Follow the disassembly procedure in the numerical order given.
2-1. CABINET (REAR) ASSY
1 screw B 1.7x12
1 screw B 1.7x12
2 Open the lid battery case.
3
3
3
6
4
5
5
5
claws
claws
cabinet (rear) assy

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2-2. MAIN BOARD
2-3. MACHANISM DECK
1 serrat IB lock
3 flexible (MEGA BASS) board
2 flexible board (HEAD)
4
4
5
MAIN board
cabinet (front) assy
mechanism dec
k
cabinet (front) assy
1
1
1
2

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3 spring (lid up)
1
2
cassette lid sub assy
cassette lid sub assy
cabinet (front) assy
cabinet (front) assy
2-4. CASSETTE LID SUB ASSY
2-5. DISPLAY BOARD
1 screws
2
1
screws
DISPLAY board
cassette lid
•Use caution when installing the
cassette holder assy
Install the cassette holder with the spring (lid up)
as shown below in the drawing so that it fits into the
holes on the cabinet front assy. Once installed,
fit the left and right pieces on.
•Press on the left & right clips from the rear of the
cabinet (front) assy. and remove the boss.

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PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :
playback head pinch roller
capstan rubber belt
2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power
supply voltage (2.5 V) unless otherwise noted.
Torque Measurement
Mode Torque Meter Meter Reading
20 – 42 g • cm
FWD CQ-102C (0.28 – 0.58 oz • inch)
FWD less than 2 g • cm
back tension (less than 0.03 oz • inch)
20 – 42 g • cm
REV CQ-102RC (0.28 – 0.58 oz • inch)
REV less than 2 g • cm
back tension (less than 0.03 oz • inch)
more than 50 g • cm
FF, REW CQ-201B (more than 0.69 oz • inch)
SECTION 4
ELECTRICAL ADJUSTMENTS
SECTION 3
MECHANICAL ADJUSTMENTS
PRECAUTION
•Supplied voltage : 2.5 V
•Switches and control position
TAPE switch : NORM
GROOVE/MEGA BASS/
NORMAL switch : NORMAL (EX402/EX404)
SOUND switch : NORMAL (EX405/EX406)
VOL control : maximum
AVLS switch : NORM
DOLBY NR switch : OFF (Except EX402)
Test Tape
Type Signal Used for
WS-48A 3 kHz, 0 dB Tape Speed Adjustment
Tape Speed Adjustment
Procedure :
1. Playback WS-48A (tape center part) in the REV state and
adjust RV601 so that the frequency counter reading becomes
3,000 Hz.
2. Playback WS-48A (tape center part) in the FWD state.
Check that frequency counter reading is within ±1.5% of the
reading of step 1.
Adjustment Location :
test tape
WS-48A
(3 kHz, 0 dB)
set
16
Ω
2 jack
frequency counte
r
RV601

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• IC Block Diagrams
IC301 LA4585M-TLM IC302 NJM2185AV-TE2
IC601 MM1370XVBE
28 18
29 17
16
15
14
13
12
10
8 9
11
30
31
32
33
34
35
36
25 24 23 222627 21 20
R.F
REF
REF
REF
REF
19
REF
REF
LOW
BOOST
SYS.
CONT
DET
DET
MIX.2
MIX.1
6 74 5321
PWR.C
PWR.1 PWR.2
MIX IN (R)
HP IN (R)
LP1
L.B.GAIN
M.B.ON/OFF
LP2
DET1
FWD/REV
PWR IN (R)
MIX OUT (R)
MIX OUT (L)
RIPPLE
REF
FWD (L)
FWD (R)
REV (R)
REV (L)
NF (L) NF (R) MIX IN (L) HP IN (L) SW OUT (L) SW OUT (R) PRE OUT (L) PRE OUT (R) PRE GND
PRE MUTE
POWER MUTE
PWR OUT (R)
VCC
COM
PWR GND
PWR OUT (L)
AVLS
DET2
PWR IN (L)
PRE2 PRE1
14 13 12 11 10 9 8
4321 5 6 7
WEIGHT
G2 G1 V/I
BIAS
CIRCUIT
Bch BLOCK (same Ach)
VCC ON/OFF VEXT INR OUTR DCR DETR
GND IREF
VREF
INL
O
UTL
DCL
DETL
SUM
Gm
Ach BLOCK
20 19 18 17 16 15 14 13 12
7 8 1096541 2 3
11
OUTPUT
BIAS
CIRCUIT
CURRENT
CONTROL VELOCITY
CONTROL
START-UP •
OSCILLATION
CIRCUIT
START-UP
CONTROL
CIRCUIT
ERROR AMP
PHASE SELECT
CIRCUIT
PRE DRIVER
START-UP
LOGIC
FORWARD/REVERSE
SELECT SWITCH
GND-2 FC RI OUT VSP IN+ VREF STAR
T
COM OSC
PU
VCC
DR
U
V
W
P-GND
PV
PW
GND-1

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IC701 TMP47C243LM-FV81CS
4321
ACUMRATOR L REGISTER PROGRAM
COUNTER
PROGRAM
MEMORY (ROM)
DATA
CONVERSION
TABLE
COMMAND
REGISTER
COMMAND
DECODER
H REGISTER
RAM ADDRESS BUFFER DATA MEMORY (RAM) STACK
TC1 TC2 DC
SPW
INTERRUPTION
PERMISSION
REGISTER
HOLD OPERATION MODE
CONTROL CIRCUIT
SYSTEM CONTROL CIRCUIT
TIMING GENERATOR
CLOCK GENERATOR
INTERRUPTION CONTROL CIRCUIT
INTERRUPTION
PERMISSION
MASTER F/F
INTERVAL
TIMER 12BIT
TIMER/
COUNTER
(2 CHANNEL)
8BIT
SERIAL
INTERFACE
WATCH DOG
TIMER ZERO
CROSS
FLAG
C Z ALUS
8BIT
A/D
CONVERTER
PULSE
OUTPUT
CIRCUIT
R7
5 6 11
R5
R6
16 15 171819
R8
20212223
R9
KE
242526
2728
12 13 147
R4
8 9 10
VDD HOLD
NC BEEP NC
NC PHOTO CTL PHOTO IN FWD/REV
REV SW REW SW FF SW FWD SW
AMP CTL
VSS
MOTOR CTL
MOTOR BRK
MOTOR DIR
SPEED CTL
OPEN DET
BATT DET
KEY IN
A/D REF
NC
MUTE
RESET
XIN
XOUT