Sony Walkman WM-FX171 User manual

WM-FX171/FX173/FX177
Canadian Model
WM-FX173/FX177
AEP Model
E Model
WM-FX171/FX173
SERVICE MANUAL
RADIO CASSETTE PLAYER
MICROFILM
SPECIFICATIONS
Model Name Using Similar Mechanism NEW
TapeTransport Mechanism Type MF-WMFX171-114
• Frequency range
FM : 87.6 - 107.9 MHz
AM : 531 - 1,602 kHz
• Power requirements
3V DC batteries R6 (AA) ×2 / External DC 3V power sources
• Dimensions
FX173 : 88.5 ×118.6 ×38.2 mm
(3 1/2×4 3/4×1 9/16 inches) (w / h / d) incl. projecting parts and controls
FX171/FX177 : 88.5 ×118.6 ×37.6 mm
(3 1/2×4 3/4×1 1/2inches) (w / h / d) incl. projecting parts and controls
• Mass
FX173 : Approx. 165 g (5.9 oz) /Approx. 245g (8.7 oz) incl. batteries
and a cassette
FX171/FX177 : Approx. 160 g (5.7 oz) / Approx. 240 g (8.5 oz) incl.
batteries and a cassette
• Supplied accessories
Stereo headphone or Stereo earphones (1) / Belt clip (1)
Design and specifications are subject to change without notice.
Photo : WM-FX173

— 2 —
TABLE OF CONTENTS
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron aroud 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.
SECTION 1
GENERAL
1. GENERAL ······································································2
2. DISASSEMBLY
2-1. Cabinet (Front) Assy ·························································· 3
2-2. Main Board ········································································· 4
2-3. Cassette Lid ········································································4
2-4. Mechanism Deck ································································5
2-5. Belt, Motor (Reel/Capstan) ················································5
3. MECHANICAL ADJUSTMENT ······························6
4. ELECTRICAL ADJUSTMENT ································6
5. DIAGRAMS
5-1. Block Diagram ··································································· 8
5-2. Schematic Diagram (FX171/FX177 Models) ·················· 10
5-3. Printed Wiring Board (FX171/FX177 Models)················13
5-4. Printed Wiring Board (FX173 Model) ····························· 17
5-5. Schematic Diagram (FX173 Model) ································21
5-6. IC Block Diagrams ···························································24
6. EXPLODED VIEWS
6-1. Cabinet Section································································· 25
6-2. Main Board Section ··························································27
6-3. Mechanism Section-1 ······················································· 28
6-4. Mechanism Section-2 ······················································· 29
7. ELECTRICAL PARTS LIST ··································· 30
Thissection is extracted
frominstruction manual.
•LOCATION OF CONTROL

— 3 —
SECTION 2
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
B
C
D
E
F
G
H
I
J
K
L
A
Cassette lid
Cabinet (front) assy
1 Two screws
[screw (B 1.7
× 9), tapping]
2-1. CABINET (FRONT) ASSY
2 Insert the precision screwdriver
(1.4 mm flat-blade) into the slit
at claw
A and release the claw.
3 Remove the cabinet (front) assy.
(Release all claws
B to L in
alphabetical order.)
•This set can be disassembled in the order shown below.
2-1. CABINET (FRONT) ASSY 2-2. MAIN BOARD
2-3. CASSETTE LID
2-4. MECHANISM DECK 2-5. BELT, MOTOR (REEL/CAPSTA
N)

— 4 —
5 Spring (torsion)
B
A
1
Open the cassette lid.
4 Cassette lid.
2-2. MAIN BOARD
2-3. CASSETTE LID
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.
3 Remove the four solders.
4 Screw (M 1.4), toothed lock (WH
)
2 Flexible board (CN302)
6 MAIN board
5 Two claws
1 Head flexible board (CN301)

— 5 —
1 Insert the precision screwdriver
(1.4 mm flat-blabe) in to the slit
and release two claws.
2 Remove the mechanism dec
k
in the direction of the arrow,
2 Two screws [screw (M 1.4), special head]
3 Motor (reel/capstan)
1 Belt
2-4. MECHANISM DECK
2-5. BELT, MOTOR (REEL/CAPSTAN)

— 6 —
SECTION 3
MECHANICAL ADJUSTMENT SECTION 4 ELECTRICAL ADJUSTMENT
PRECAUTION
1. Clean the following parts with a denatured-alcahol-moistened
sweb :
Playback head Pinch roller
Rubber belt Capstan
2. Demagnetize the playback head using a demagnetizer.
3. Do not use a magnetized screwdriver for adjustments.
4. After adjusting, apply screw-locking compound onto the
adjusted parts.
5. Unless specified otherwise, use a specified voltage (3.0V) to
perform the adjustments.
Torqu Measurement
Mode
FWD
FWD
Back Tension
REV
REV
Back Tension
FF
REW
Torque meter
CQ-102C
CQ-102RC
CQ-201B
Meter reading
20 - 30 g · cm
0.4 - 2.0 g · cm
20 - 30 g · cm
0.4 - 2.0 g · cm
More than 40 g · cm
PRECAUTION
1. Specified voltage : 3.0V
2. Switch position
AVLS switch : NORM
CASSETTE SECTION
Test Tape
Tape Speed Adjustmnet
Procedure :
1. PlaybackWS-48A(Tape center part) and adjust RV601 so that
the frequency counter reading becomes 3,000Hz ± 15Hz.
2. Playback WS-48A (Tape top and end).
Check that frequency counter reading is within 1.5% of the
reading of step1.
Adjustment Point :
[MAIN BOARD] — SIDE B —
Type
WS-48A Signal 3kHz, 0dB Purpose Tape SpeedAdjustment
Test tape
WS-48A
(3kHz, 0dB)
Set
* 1
PHONES jack
+
–
Frequency counte
r
RV601 : Tape Speed
*1
16Ω: E, EA, C & SA, PAModels.
32Ω: AEP, IT, E, CND, FR Models.
• Abbreviation
CND : Canadian
IT : Italian
EE : East European
EA : Saudi Arabia
FR : French
PA : Panama
C & SA : Central and South America

WM-FX171/FX173/FX177
— 10 — — 11 — — 12 —
5-2. SCHEMATIC DIAGRAM
(FX171/FX177 MODELS)
Note:
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
• All resistors are in Ωand 1/4W or less unless otherwise
specified.
•¢: internal component.
•C: panel designation.
•U: B+ Line.
•H: adjustment for repair.
• Total current is measured with no cassette installed.
• Power voltage is dc 3V and fed with regulated dc power
supply from external power voltage jack.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
no mark : PB (TAPE)
( ) : AM
< > : FM
• Voltagesare taken with a VOM (Input impedance 10 MΩ).
Voltage variations may be noted due to normal produc-
tion tolerances.
• Signal path.
F: FM
f: AM
E: PB
• Abbreviation
CND : Canadian model
IT : Italian model
EE : East European model
EA : SaudiArabia model
FR : French model
PA : Panama model
C & SA: Central and SouthAmerica models
10 101010

WM-FX171/FX173/FX177
5-3. PRINTED WIRING BOARD
(FX171/FX177 MODELS)
Ref. No. Location
D120 G-13
IC1 F-14
IC301 E-17
IC601 E-18
Q2 G-14
Q101 E-15
Q201 E-15
Q301 F-16
Q302 F-14
• Semiconductor
Location
— 13 — — 15 — — 16 —
Note:
•X: parts extracted from the component side.
•®: Through hole.
•b: Pattern from the side which enables seeing.
(The other layers' patterns are not indicated.)
Caution:
Pattern face side: Partson thepattern face side seen from
(Conductor B) the pattern face are indicated.
Parts face side: Parts on the parts face side seen from
(Component A) the parts face are indicated.
12
A
B
C
D
E
F
G
H
I
3 4 5 6 7 8 9 1011121314151617181920212223
MAIN BOARD (SIDE B)
MAIN BOARD (SIDE A)
1-667-714- 11
(11)
1
5
9
1018
19 15
27
28 36
30
25
16
(POWER)
L
R
HP901
(PLAYBACK HEAD)
4
5
3
2
16
(BATT)
RV301
(VOLUME)
FM AM TAPE
(RADIO OFF)
L
R
5
124
20
15
1312
10
16
2/4
3/4
1/4
4/4
TUNING
L1 EXCEPT C&SA,PA,FX177
MODEL
EXCEPT
C&SA,PA,
FX177
MODEL
C&SA,PA
FX177 MODEL
C&SA,PA,
FX177
MODEL
S305
AVLS
NORM
LIMIT
NORM
CrO
2 /
METAL
FM ST
MONO
DX
LOCAL
J302
BLK
BLK
ORG
ORG
RED
RED
WHT
WHT
M901
REEL/CAPSTAN
MOTOR
MEGA BASS UNIT
OFF
ON
DRY BATTERY
SIZE "AA"
(IEC DESIGNATION R6)
2PCS, 3V
J301
DC IN 3V
E,C&SA,EA,PA
MODEL
4
6
2
•Abbreviation
CND : Canadian
IT : Italian
EE : East European
EA : Saudi Arabia
FR : French
PA : Panama
C & SA: Central and South America
— 14 —