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­ 1 ­
Model Name Using Similar Mechanism
WM-FX551/FX553
Tape Transport Mechanism Type
MF-WMFX551-125
SERVICE MANUAL
Tourist Model
WM-FX571
RADIO CASSETTE PLAYER
Ver 1.0 1999. 03
SPECIFICATIONS
Radio section
Frequency range
FM : 87.5 ­ 108 MHz
AM : 531 ­ 1,602 kHz
Tape section
Frequency response
(Dolby NR off)
Playback : 20 ­ 18,000 Hz
Output
Headphones (
2 REMOTE jack)
Load impedance 8 ­ 300
General
Power requirements
1.5 V
One R6 (size AA) battery
Rechargeable battery
Dimensions (w/h/d)
Approx. 109
× 79.2 × 29.4 mm
(4 3/8
× 3 1/8 × 1 3/16 inches) incl.
projecting parts and controls
Mass
Approx. 150 g (5.3 oz)
Approx. 210 g (7.5 oz) incl.
a battery and a cassette
Supplied accessories
Stereo earphones with remote
control MDR-WMF653 (1)
Battery charger BC-820T (1)
AC plug adaptor (1)
Rechargeable battery (NC-AA) (1)
Battery R6P (SR) (1)
Carrying pouch (1)
Design and specifications are subject to
charge without notice.
Manufactured under license from Dolby Laboratories
Licensing Corporation.
"DOLBY" and the double-D symbol
a are trademarks
of Dolby Laboratories Licensing Corporation.
MICROFILM


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TABLE OF CONTENTS
1. GENERAL .................................................................... 3
2. SERVICE NOTE .......................................................... 3
3. DISASSEMBLY
3-1. Case Assy ............................................................................ 4
3-2. Tuner Board ........................................................................ 4
3-3. Audio Board ........................................................................ 5
3-4. Cassette Lid Assy ................................................................ 5
3-5. Tape Mechanism Deck ........................................................ 6
4. MECHANICAL ADJUSTMENTS .............................. 7
5. ELECTRICAL ADJUSTMENTS
Tape Section ............................................................................ 7
Tuner Section ........................................................................... 8
6. DIAGRAMS
6-1. Block Diagram .................................................................... 9
6-2. IC Pin Description ............................................................. 11
6-3. Printed Wiring Boards ­Tuner Section­ ........................... 13
6-4. Schematic Diagram ­Tuner Section­ ................................ 17
6-5. Schematic Diagram ­Audio Section­ ............................... 20
6-6. Printed Wiring Board ­Audio Section­ ............................ 23
7. EXPLODED VIEWS
7-1. Cabinet Section ................................................................. 29
7-2. Audio and Tuner Board Section ........................................ 30
7-3. Tape Mechanism Section .................................................. 31
8. ELECTRICAL PARTS LIST .................................... 32
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.


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­ 3 ­
screw
(M1.4
× 5.0)
screw (M1.4
× 5.0)
TUNER board
screw (M1.7
× 4.0)
screw
(M1.4
× 5.0)
JIG
AUDIO board
0
!TM
!
9
8
7
6
5
4
3
2
1
SECTION 1
GENERAL
· LOCATION OF CONTROLS
SECTION 2
SERVICE NOTE
· Regarding the method of adjustment and voltage check, perform sections 3-1 and 3-2 of the DISASSEMBLY, and attach the JIG (extension
cable) to the AUDIO board as shown below.
JIG Part No.: J-2503-005-A
1 OPEN knob
2 Display window
3 PRESET + /AMS FF (Fast Forward) button
4 TUNING + button
5 TUNING ­ button
6 ENTER button
7 PRESET ­ /AMS REW (Rewind) button
8 MENU button
9 RADIO ON/BAND button
!º SET button
!¡ p /RADIO OFF button
!TM "" /REPEAT button
!£ VOLUME control
!¢ C HOLD knob
! 2 REMOTE jack
!§ Battery case
!¶ DC IN 1.5V jack


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­ 4 ­
1 screw (M1.7
× 6)
5 TUNER board
4
3 screw
(M1.4
× 4.5)
7 guide (TU)
6
2 screw (M1.7
× 3)
1 screw (M1.7
× 6)
6 case assy
4 claws
3 screws
(M1.4
× 2.2)
1 screw
(M1.4
× 2.2)
2 screw
(M1.4
× 3.0)
5
CASE ASSY
TUNER BOARD
AUDIO BOARD
CASSETTE LID ASSY
TAPE MECHANISM DECK
SET
SECTION 3
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
3-1. CASE ASSY
3-2. TUNER BOARD
Note : Disassemble the unit in the order as shown below.


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­ 5 ­
2 screw (M1.4
× 2)
5 cassette lid assy
3 screw (M1.4
× 1.6)
1 OPEN button
4
7 AUDIO board
1 Unsolder the 3 places.
2 battery terminal (­)
4 battery terminal (+)
3 Unsolder the 5 places.
5 Flexible board
6
3-3. AUDIO BOARD
3-4. CASSETTE LID ASSY