Sony WMFX-481 Service manual
WM-FX481
SERVICE MANUAL
Ver 1.0 2001.04
Model Name Using Similar Mechanism NEW
MD Mechanism Type
SPECIFICATIONS
E Model
Chinese Model
MF-WMFX481-114 (5E, 6E, 9E)
MF-WMFX467-114 (CH)
• Abbreviation
CH : Chinese
9E : No Indication of country of origin
5E, 6E : Indication of country of origin
9-873-125-11
2001D0200-1
© 2001.4
RADIO CASSETTE PLAYER
Sony Corporation
Personal Audio Company
Shinagawa Tec Service Production Group
WM-FX481
TABLE OF CONTENTS
Specifications ........................................................................... 1
1. GENERAL ...................................................................... 2
2. DISASSEMBLY
2-1. Cabinet (Front), Cabinet (Center) Sub ASSY ............ 3
2-2. Main Board ................................................................. 3
2-3. Mechanism Deck ........................................................ 4
2-4. Belt, Capstan/reel Motor (M601),
Magnetic Head (Playback) (HP601) ........................... 4
2-5. Cassette Holder ........................................................... 5
3. ADJUSTMENTS
3-1. Mechanical Adjustments............................................. 6
3-2. Electrical Adjustments ................................................ 6
4. DIAGRAMS
4-1. Explanation of IC Terminals ....................................... 9
4-2. Block Diagram .......................................................... 10
4-3. Schematic Diagram ....................................................11
4-4. Printed Wiring Boards – Main Section (Side A) – ... 12
4-5. Printed Wiring Boards – Main Section (Side B) – ... 13
5. EXPLODED VIEWS
5-1. Cabinet Section ......................................................... 15
5-2. Mechanism Deck Section
(MF-WMFX467-114:CH)
(MF-WMFX281-114:5E, 6E, 9E)..... 16
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 damaged by heat.
6. ELECTRICAL PARTS LIST ................................... 17
SECTION 1
GENERAL
2
SECTION 2
Y
Y
DISASSEMBLY
z
The equipment can be removed using the following procedure.
Set
Cabinet (front)
Main boardCabinet (center) sub ASSY
Cassette holder
Note : Follow the disassembly procedure in the numerical order given.
2-1. CABINET (FRONT), CABINET (CENTER) SUB ASSY
Note : Use the precision driver with coverd a point
by cloth to release the claw.
Be careful not to damage claws.
Cassette holder
Mechanism deck Belt, Capstan/reel motor (M601)
WM-FX481
Magnetic head (playback) (HP601)
3 Claws
2-2. MAIN BOARD
Main board
1 Claws
1 Claws
2
5
Cabinet (center) sub ASS
4 Claw
4 Claw
1 Claws
Cabinet (Front)
1 Screw
3 Claws
Head flexible board
4
2 Remove solder
Orange
Black
White
Red
Cabinet (center) sub ASS
3
WM-FX481
Y
2-3. MECHANISM DECK
Mechanism deck
1 Claws
2
Cabinet (center) sub ASS
2-4. BELT, CAPSTAN/REEL MOTOR (M601), MAGNETIC HEAD (PLAYBACK) (HP601)
3
Screws (M1.4)
5
Screws (M1.4)
4
Capstan/reel motor
(M601)
6
magnetic head
(PLAYBACK)
(HP601)
Mechanism deck
• How to apply the belt
Belt
Capstan/reel motor
(M601)
1
Claw
wheel ASSY (P), capstan
wheel ASSY (P), capstan
Stopper
2
Belt
4
2-5. CASSETTE HOLDER
r
2 Move the hinge away
from projection
WM-FX481
Projection
Cabinet (center)
sub ASSY
Hinge
Hinge
Cassette holder
1
Projection
5
Hinge
Hinge
Projection
3 Move the hinge away
from projection
Projection
4 Spring (torsion)
z
CAUTIONS DURING ASSEMBLY
1 Insert the spring (torsion) to the L shape slot as shown in the figure.
2,3 Insert the hinge of the “Cassette holder ”.
4 Close the “Cassette holder” then press it.
Hinge
Spring (torsion)
L shape slot
1
2
4
Cassette holde
Hinge
3
Cabinet (center) sub ASSY
5
WM-FX481
r
t
SECTION 3
ADJUSTMENTS
3-1. MECHANICAL ADJUSTMENTS
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.
Do not use a magnetized screwdriver for the adjustments.
3. These measurement and adjustment should be performed with
the rated power supply voltage (2.5 V) unless otherwise noted.
Torque Measurement
Mode Torque meter Meter reading
FWD
CQ-102C
FWD
back tension
REV 20 – 42 g • cm
CQ-102RC
REV
back tension
FF, REW CQ-201B
1.97 – 4.11 mN • m
20 – 42 g • cm
(0.28 – 0.58 oz• inch)
less than 0.19 mN • m
less than 2 g • cm
(less than 0.027 oz• inch)
1.97 – 4.11 mN • m
(0.28 – 0.58 oz• inch)
less than 0.19 mN • m
less than 2 g • cm
(less than 0.027 oz• inch)
more than 5.89 mN • m
more than 60 g • cm
(more than 0.84 oz• inch)
3-2. ELECTRICAL ADJUSTMENTS
PRECAUTION
• Supplied voltage : 2.5V.
• Switch and control position (MENU display)
MEGA BASS : OFF
VOLUME control (RV301) : maximum
AVLS : OFF (No indicated)
FM MODE : 5E, 6E : DX (No indicated)
9E, CH : STEREO (No indicated)
• Abbreviation
CH : Chinese
9E : No Indication of country of origin
5E, 6E: Indication of country of origin
TAPE SECTION
Test Tape
Type Signal Used for
WS-48A 3kHz, 0dB Tape Speed Adjustment
Tape Speed Adjustment
Procedure :
test tape
WS-48A
(3kHz, 0dB)
0 dB = 0.775V
frequency counte
16 Ω
set
phones jack (J301)
1. Playback WS-48A (tape center part) in the FWD state and adjust RV601 so that the frequency counter reading becomes
3,000Hz.
Standard value : 2,985–3,015Hz
2. Playback WS-48A (tape center part) in the REV state.
Check that frequency counter reading is within ±1.0% of the
reading of step 1.
Adjustment Location :
RV601 : Tape speed Adjustmen
6
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