Sony WMFX-141 Service manual

WM-FX141
SERVICE MANUAL
Ver 1.3 1999. 05
With SUPPLEMENT-1 (9-923-296-81) With SUPPLEMENT-2 (9-923-296-82)
US Model
AEP Model
E Model
Model Name Using Similar Mechanism WM-FX101 Tape Transport Mechanism Type MF-WMFX103-48
SPECIFICATIONS
Radio Frequency
FM : 87.6 – 108 MHz (US, Chilean, Latin America, Central and
South America Models) : 65.0 – 107.9MHz (East European Model) : 87.6 – 107.9 MHz (Other Models)
AM : 530 – 1,710 kHz (US, Chilean, Latin America, Central and
South America Models) : 531 – 1,602kHz (Other Models)
Power requirements
3V DC batteries R6 (size AA) × 2 External DC 3V power sources
Battery life
(Aprroximate hours)
Battery Playback Radio Sony alkaline LR6 (SG) 16 hrs 48 hrs Sony R6P (SR) 4.5 hrs 16 hrs
Dimensions
93.9 × 118.5 × 35.9 mm (w/h/d) (33/4 × 43/4 × 13/16 in.) incl. projecting parts
Mass
205g (7.3 oz) incl.batteries
Supplied accessories
Stereo headphones or earphones (1)
Belt clip (1)
Design and specifications are subject to change without notice.
MICROFILM
RADIO CASSETTE PLAYER
TABLE OF CONTENTS
1. GENERAL ·········································································· 3
2. DISASSEMBLY
2-1. Cabinet (Rear) ································································· 4 2-2. Mechanism Deck and Main Board ································· 4 2-3. Main Board ····································································· 5 2-4. Cassette Lid····································································· 5 2-5. Dial Pointer Setting························································· 5
3. ADJUSTMENT
3-1. Mechanical Adjustment ·················································· 6 3-2. Electrical Adjustment······················································6
4. DIAGRAMS
4-1. Block Diagram ································································ 9 4-2. Schematic Diagram ······················································· 11 4-3. Printed Wiring Board ···················································· 13 4-4. IC Block Diagram ························································· 17
5. EXPLODED VIEWS
5-1. Cabinet and Board Section ··········································· 18 5-2. Mechanism Section (MF-WMFX103-48) ···················· 19
6. ELECTRICAL PARTS LIST ······································· 20
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.
Flexible Circuit Board Repairing
• Keep the temperature of 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.
— 2 —
SECTION 1

GENERAL

This section is extracted from instruction manual.
— 3 —

DISASSEMBLY

k
Note : Disassemble the unit in the order as shown below.
SECTION 2
Cabinet (Rear) Mechanism deck and main board
Main board Cassette lid
Dial pointer setting
Note : Follow the disassembly procedure in the numerical order given.
2-1. CABINET (REAR)
B
F
G
H
J
C
D
E
I
K
M
L
Cabinet(rear)
Cassette lid
A
1
Open the cassette lid and release claw A.
2
Remove the cabinet(rear).(Release
all claws
B
from M in alphabetical order.)
2-2. MECHANISM DECK AND MAIN BOARD
1
Remove the mechanism deck and main board in the direction of the arrow.
head flexible board
mechanism dec and MAIN board
*
note for installation : Make sure to put the head flexible board to ditch before install the mechanism deck and MAIN board.
— 4 —
2-3. MAIN BOARD
d
t
r
1
head flexible board
2
claws
3
MAIN boar
2-4. CASSETTE LID
A
1
Release the catch A.
B
2
Release the catch B.
3
Cassette lid (Remove it in the direction of the arrow)
Front cabine
2-5. DIAL POINTER SETTING
Pointer
B
2
Align pointer with arrow marked side as shown in Fig.1 and then fit to groove in the order of
A
1
Rotate tune knob fully to arrow direction.
A
and B.
Fig. 1
— 5 —
Align
Pointe
SECTION 3

ADJUSTMENTS

3-1. MECHANICAL ADJUSTMENTS
Precaution
1. Clean the following parts with a denatured-alcohol-moistend swab :
playback head pinch roller capstan rubber belts
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 perfomed with the rated power supply voltage (2.5V) unless otherwise noted.
Torque Measurement
Mode Torque meter Meter reading
FWD FWD
Back T ension
FF, REW
CQ-102C
CQ-201B
20 to 42 g•cm (0.28 to 0.58 oz•inch) less than 2 g•cm (less than 0.03 oz•inch) more than 60 g•cm (more than 0.83 oz•inch)
3-2. ELECTRICAL ADJUSTMENTS
Precaution
Supplied voltage : 2.5V
Switch and control position
TAPE switch : NORM VOLUME control : maximum AVLS switch : OFF
TAPE SECTION
FUNCTION switch : TAPE
Test tape
Type Signal Used for
WS-48A 3kHz, 0dB Tape Speed Adjustment
Tape speed adjustment
Tape selection adjustment : NORM
Procedure :
test tape WS-48A (3kHz, 0dB)
16
0dB=0.775V
frequency counter
set
J302(phones)
Adjustment V alue: normal tape speed Adjust the tape speed adjustment R V601, so that the freqency counter reading becomes 3,000Hz.
Specification Value:
Digital frequency counter
2,945 to 3,015Hz
Frequency difference between the beginning and the end of the tape should be within 1.5% (45Hz).
Adjustment Location :
— 6 —
TUNER SECTION
l
r
[AM]
BAND: AM Signal generator
AM RF signal generator
30% amplitude modulation by 400Hz signal. Output level : as low as possible
Put the lead-wire antenna close to the set.
0 dB = 1 µV
Repeat the procedures in each adjustment several times for the maximum level meter indication.
The frequency coverage and tracking adjustments should be finally done by the trimmer capacitors.
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1 455kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1 620kHz(800kHz)
CT1 1,400kHz(1,300kHz)
[FM]
BAND : FM Signal generator
FM RF signal generator
75kHz(100%) amplitude modulation by 1kHz signal. Output level: as low as possible
set
0.01µF
16
J302 (phones)
antenna termina
level mete
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L4 505kHz(516.5kHz)
CT4 1,750kHz(1,631.5kHz)
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L2 86.0MHz[64MHz]
CT2 109.5MHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L3 86.0MHz[64MHz]
CT3 109.5MHz
( ) :E, Mexican, East European, AEP
[ ] : East European
Adjustment Location: Main board (See page 8)
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