Sony WMFX-277 Service manual
WM-FX277
SERVICE MANUAL
Ver 1.0 2001.03
SPECIFICATIONS
E Model
Chinese Model
Model Name Using Similar Mechanism NEW
MD Mechanism Type MF-WMFX241-114
9-927-695-31
2001C0200-1
© 2001.3
RADIO CASSETTE PLAYER
Sony Corporation
Audio Entertainment Group
General Engineering Dept.
WM-FX277
TABLE OF CONTENTS
Specifications ........................................................................... 1
1. SERVICING NOTE ...................................................... 3
2. GENERAL ...................................................................... 3
3. DISASSEMBLY
3-1. Cabinet (Front) ........................................................... 4
3-2. Main Board ................................................................. 4
3-3. Mechanism Deck ........................................................ 5
3-4. Belt, Capstan/reel Motor (M601),
Magnetic Head (Playback) (HP601) ........................... 5
3-5. Cassette Holder ........................................................... 6
4. ADJUSTMENTS
4-1. Mechanical Adjustments ............................................ 7
4-2. Electrical Adjustments ................................................ 7
5. DIAGRAMS
5-1. Explanation of IC Terminals ..................................... 10
5-2. Block Diagram ...........................................................11
5-3. Printed Wiring Boards – Main Section (Side A) – ... 12
5-4. Printed Wiring Boards – Main Section (Side B) – ... 13
5-5. Schematic Diagram ................................................... 14
6. EXPLODED VIEWS
6-1. Cabinet Section ......................................................... 17
6-2. Mechanism Deck Section (MF-WMFX241-114)..... 18
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.
7. ELECTRICAL PARTS LIST ................................... 19
2
WM-FX277
SECTION 1
SERVICING NOTE
In case of adjusting Tape Speed, you can easily to adjust RV601 by removing 7 claws on Window (LCD) and itself as shown in the figure.
1.Insert the precision screwdriver (Cover a point by cloth) in to the slit at claw.
2.Remove the window(LCD).
Note: Be careful not to damage claws.
Claws
Claws
Window(LCD)
Claws
RV601
LOCATION AND FUNCTION OF CONTROLS
SECTION 2
GENERAL
This section is extracted from
instruction manual.
3
WM-FX277
Y
Y
SECTION 3
DISASSEMBLY
• The equipment can be removed using the following procedure.
Set
Cabinet (Front)
Main boardCassette holder ASSY
Cassette holder
Note : Follow the disassembly procedure in the numerical order given.
3-1. CASSETT HOLDER ASSY, CABINET (FRONT)
Note : Use the precision driver with coverd a point
by cloth to release the claw.
Be careful not to damage claws.
3
Claws
1
Claws
Mechanism deck Belt, Capstan/reel motor (M601),
Magnetic head (Playback) (HP601)
Cassette holder ASS
2
4
Claws
4
5
Claw
3-2. MAIN BOARD
Main board
3
Claws
1
Claws
4
1
Screw
Cabinet (Front)
2
Remove solder
Orange
Black
White
Red
1
Claws
Cassette holder ASS
Head flexible board
4
3-3. MECHANISM DECK
Y
k
Mechanism deck
1
Claws
WM-FX277
2
Cassette holder ASS
3-4. BELT, CAPSTAN/REEL MOTOR (M601), MAGNETIC HEAD (PLAYBACK)(HP601)
3
Screws (M1.4)
5
Screws (M1.4)
4
Capstan/reel motor
(M601)
Mechanism dec
6
magnetic head
(PLAYBACK)
(HP601)
1
Claw
Stopper
2
Belt
5
WM-FX277
r
3-5. CASSETTE HOLDER
2
Move the hinge away
from projection
Projection
Cabinet (center)
Cassette holder
z
CAUTIONS DURING ASSEMBLY
Hinge
1
Hinge
Projection
5
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
Hinge
Projection
3
Move the hinge away
from projection
Projection
4
Spring (torsion)
L shape slot
Hinge
Spring (torsion)
1
2
Cassette holde
4
Hinge
3
Cabinet (center)
6
SECTION 4
r
t
ADJUSTMENTS
WM-FX277
4-1. 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 (less than 0.027 oz• inch)
FF, REW CQ-201B
1.97 to 4.90 mN•m
20 to 50 g • cm
(0.28 to 0.69 oz• inch)
less than 0.19 mN•m
less than 2 g • cm
5.89 to 19.61 mN•m
60 to 200 g • cm
(0.84 to 2.77 oz• inch)
4-2. ELECTRICAL ADJUSTMENTS
PRECAUTION
• Supplied voltage : 2.5V.
• Switch and control position
MEGA BASS (S709) : OFF
VOLUME control (RV301) : maximum
AVLS (S304) : NORM
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
set
frequency counte
16
Ω
phones jack (J301)
1. Playback WS-48A (tape center part) and adjust RV601 so that
the frequency counter reading becomes 3,000Hz.
Standard value : 2,985–3,015Hz
2. Playback WS-48A (tape top and end) .
Check that frequency counter reading is within ±1.0% of the
reading of step 1.
Adjustment Location :
Refer to page 3 for Servicing note
RV601:
Tape speed Adjustmen
7
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