Sony Walkman WM-FX271 User manual

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MICROFILM
SERVICE MANUAL
US Model
WM-FX271/FX275
Canadian Model
AEP Model
E Model
Chinese Model
WM-FX271
WM-FX271/FX275
RADIO CASSETTE PLAYER
Photo: WM-FX271
Frequency range
FM: 65 – 74/87.5 – 108 MHz (East European)
87.5 – 108 MHz (Except East European)
AM:530 – 1,710 kHz (US, Canadian)
531 – 1,602 kHz (Except US, Canadian)
Power requirements
3 V DC batteries R6 (AA) ×2/External DC 3 V power sources
Dimensions
91.4 ×115.5 ×35.9 mm (3 5/8 ×4 5/8 ×1 7/16 inches) (w/h/d) incl.
projecting parts and controls
Mass
Approx. 150 g (5.3 oz.)
Approx. 230 g (8.2 oz.) incl.batteries and a tape
Supplied accessories
Stereo headphones or Stereo earphones (1)/Carrying case (1)
Design and specifications are subject to change without
notice.
SPECIFICATIONS
Model Name Using Similar Mechanism WM-FX171
Tape Transport Mechanism Type MF-WMFX171-114
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.
Ver 1.0 1999. 02

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TABLE OF CONTENTS
1. GENERAL ........................................................................... 3
2. DISASSEMBLY
2-1. Cabinet (Front) Sub Assy .................................................... 4
2-2. Main Board ......................................................................... 5
2-3. Holder (Sub) Assy, Cassette ................................................ 5
2-4. Mechanism Deck................................................................. 6
2-5. Belt and Motor .................................................................... 6
3. MECHANICAL ADJUSTMENTS ................................. 7
4. ELECTRICAL ADJUSTMENTS
Tape Section ............................................................................ 7
Tuner Section........................................................................... 8
5. DIAGRAMS
5-1. IC Pin Description............................................................. 10
5-2. Block Diagram .................................................................. 11
5-3. Printed Wiring Board ........................................................ 13
5-4. Schematic Diagram ........................................................... 15
6. EXPLODED VIEWS
6-1. Cabinet Section ................................................................. 18
6-2. Tape Mechanism Section-1 ............................................... 19
6-3. Tape Mechanism Section-2 ............................................... 20
7. ELECTRICAL PARTS LIST ........................................ 21

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SECTION 1
GENERAL This section is extracted
from instruction manual.

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SECTION 2
DISASSEMBLY
2-1. CABINET (FRONT) SUB ASSY
Note : When installing, fit the knobs and switches.
Cabinet (front) sub assy Main boardSet Holder (sub) assy, cassette Belt and Motor
Mechanism deck
1 Insert the precision screwdriver
(1.4 mm flat-blade) into the slit
at claw A and release the claw.
2 Remove the cabinet (front) sub assy.
(Release all claws B to N in
alphabetical order.)
• The equipment can be removed using the following procedure.
A
cabinet (front) sub assy
holder (sub) assy, cassette
B
C
D
E
FHI
J
K
S71
6
G
L
M
N
cabinet (front) sub assy
Note :When removing the cabinet, put cloth
on the end of a screwdriver or use a
polyacetal driver to avoid damage to
the cabinet.
Note : Follow the disassembly procedure in the numerical order given.

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2-2. MAIN BOARD
4 two claws
1 HEAD FLEXIBLE board (CN301)
2 Unsolder the 4 places.
5 MAIN board
3 screw (M1.4), toothed lock (WH)
1 Open the holder (sub) assy, cassette.
4 holder (sub) assy, cassette.
A
B5
spring (torsion
)
2-3. HOLDER (SUB) ASSY, CASSETTE
2 Insert a precision screwdriver
(1.4 mm flat-blade) vertically
into portion A to release the
hinge plate.
3 Portion B to release the
hinge plate.

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2-4. MECHANISM DECK
2-5. BELT AND MOTOR
1 Insert the precision screwdriver
(1.4 mm flat-blade) into the slit
and release three claws.
2 Remove the mechanism deck
in the direction of the arrow.
• How to apply the belt
1 belt
3 motor
2 two screws (screw (M1.4), special head)
wheel assy (NP), capstan
belt
M901

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0000
2 jack (J301)
digital frequency
counter
set
16
Ω
test tape
WS-48A
(3 kHz, 0 dB)
PRECAUTION
• Supplied voltage : 2.5V
• Switch and control position
VOLUME control : maximum
AVLS switch : NORM
• Test Tape
Type Signal Used for
WS-48A 3 kHz, 0 dB tape speed adjustment
TAPE SECTION 0 dB = 0.775 V
Tape Speed Adjustment
Procedure:
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :
playback head pinch lever assy
capstan wheel assy 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 (2.5V) unless otherwise noted.
Torque Measurement
Mode Torque meter Meter reading
FWD CQ-102C 20 – 42 g • cm
(0.28 – 0.58 oz • inch)
FWD CQ-102C less than 2 g • cm
Back Tension (less than 0.03 oz • inch)
FF, REW CQ-201B more than 60 g • cm
(more than 0.83 oz • inch)
SECTION 4
ELECTRICAL ADJUSTMENTS
SECTION 3
MECHANICAL ADJUSTMENTS
1. Playback WS-48A (tape center part) in the FWD state and
adjust RV601 so that the frequency counter reading
becomes 3,000 Hz.
Specification Value:
Digital frequency counter
2,985 to 3,015 Hz
Adjustment Location:
RV601

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2 jack (J301)
set
16
Ω
level meter
(range: 0.5-5 V ac
)
Put the lead-wire
antenna close to
the set.
AM RF signal
generator
digital
voltmeter
TP (VT)
Main board
• Repeat the procedures in each adjustment several times, and the
tracking adjustment should be finally done by the trimmer ca-
pacitors.
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
1,000 (999) kHz
( ): Except US, Canadian model
AMTRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1 CT1
620 (621) kHz 1,400 (1,395) kHz
( ): Except US, Canadian model
TUNER SECTION 0 dB = 1 µV
• FM Section
Setting:
RADIO ON/OFF switch: ON
BAND switch : FM
FM Tuning Voltage Adjustment
FM TUNING VOLTAGE ADJUSTMENT
Adjust for a 8.5 ± 0.3 (14.5 ± 0.5)Vdc reading on digital voltmeter.
L3
108 MHz
FMTracking Adjustment
Modulation: 1 kHz, 75 kHz dev. (100%)
Output level: as low as possible
digital
voltmeter
TP (VT)
Main board
FM RF signal
generator
0.01 µ F(FM RF IN)
Main boar
d
(GND)
2 jack (J301)
set
16
Ω
level meter
(range: 0.5-5 V ac
)
FMTRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L2
87.5 (65.0) MHz
( ): East European model
• AM Section
Setting:
RADIO ON/OFF switch: ON
BAND switch : AM
AMTuning Voltage Adjustment
AMTUNING VOLTAGE ADJUSTMENT
Adjust for a 1.1 ± 0.1 Vdc reading on digital voltmeter.
L4
530 (531) kHz
( ): Except US, Canadian model
AM IF Adjustment, AMTracking Adjustment
Modulation: 400Hz, 30%
Output level: as low as possible

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L3
FM TUNING
VOLTAGE
ADJUSTMENT
L2
FM TRACKING
ADJUSTMENT
L4
AM TUNING
VOLTAGE
ADJUSTMENT
T1
AM IF
ADJUSTMENT
CT1
AM TRACKING
ADJUSTMENT
L1
Adjustment Location: main board
Measurement Points: main board
(FM RF IN)
(VT)
FM RF INVT

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5-1. IC PIN DESCRIPTION
• IC701 µPD17072GB-559-1A7 (SYSTEM CONTROL/LCD DRIVE)
Pin No. Pin Name I/O Pin Description
1 INIT O Initialize output
2, 3 NC — Not used.
4 MEGA BASS O MEGA BASS ON/OFF output (L: ON, H: OFF)
5 RADIO-ON O Radio circuit power control output
6 – 8 KEY OUT1 – 3 O Key matrix output 1 – 3
9 NC — Not used.
10, 11 KEY IN1, 3 I Key input 1, 3
12, 13 BTT-REF1, 2 I Reference voltage input for battery voltage check.
14 MUTE OUT O Mute output (Mute ON: L, Mute OFF: input)
15 SD I SD (with local) signal input
16 BAND O Radio band select output (AM: L, FM: input)
17 HOLD I Key hold input (Key input effect: L, Key input ineffect: H)
18 GND — Ground
19 EO O PLL error out output
20 VCO (AM) I VCO (AM) input
21 VCO (FM/TV) I VCO (FM) input
22 VDD2 — Voltage regulator for PLL.
23 VDD1 — Power supply pin
24 XO — Crystal oscillator output (75 kHz)
25 XI — Crystal oscillator input (75 kHz)
26 VDD5 — Voltage regulator for oscillation circuit.
27 VDD3 — Power supply for LCD driver.
28, 29 CAP1, 2 — Stabilized capacitor connection of crystal oscillation power supply.
30 VDD4 — Power supply for LCD driver.
31 – 34 COM0 – 3 O LCD driver common output
35 – 49 LCD0 – 14 O LCD driver output
50 CE I L: Clock stop, H: Normally operation
51 TAPE ON I At TAPE ON: H
52 BEEP O BEEP output
53 NC — Not used.
54 KEY IN2 I Key input 2
55 NC — Not used.
56 KEY IN4 I Key input 4
SECTION 5
DIAGRAMS