2
WM-EX921
TABLE OF CONTENTS
1.
SERVICING NOTES
...............................................
3
2.
GENERAL
...................................................................
5
3.
DISASSEMBLY
3-1. Disassembly Flow ...........................................................
6
3-2. Case Section ....................................................................
6
3-3. MAIN Board ...................................................................
7
3-4. Belt (F0) ..........................................................................
7
3-5. Motor, DC (Capstan/Reel) (M601) .................................
8
3-6. Lid Assy, Cassette ...........................................................
8
3-7. Ornament (Open) Block Assy .........................................
9
3-8. Holder (FA) Assy ............................................................
9
3-9. “Lever (N2) Assy, Pinch”, “Lever (R2) Assy, Pinch” .... 10
3-10. Head, Magnetic (Playback) (HP901) ............................. 10
4.
MECHANICAL ADJUSTMENTS
....................... 11
5.
ELECTRICAL ADJUSTMENTS
......................... 11
6.
DIAGRAMS
6-1. Block Diagram ................................................................ 13
6-2. Note for Printed Wiring Board
and Schematic Diagrams ................................................ 14
6-3. Printed Wiring Board
– MAIN Board (Component Side) – .............................. 16
6-4. Printed Wiring Board
– MAIN Board (Conductor Side) – ................................ 17
6-5. Schematic Diagram – MAIN Board (1/2) – .................. 18
6-6. Schematic Diagram – MAIN Board (2/2) – .................. 19
6-7. IC Pin Function Description ........................................... 20
7.
EXPLODED VIEWS
7-1. Cassette Lid Assy Section ............................................... 21
7-2. Case Section .................................................................... 22
7-3. MAIN Board Section ...................................................... 23
7-4. Mechanism Deck Section-1 (MT-WMEX921-162) ....... 24
7-5. Mechanism Deck Section-2 (MT-WMEX921-162) ....... 25
7-6. Mechanism Deck Section-3 (MT-WMEX921-162) ....... 26
8.
ELECTRICAL PARTS LIST
............................... 27
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.
Flexible Circuit Board Repairing
• Keep the temperature of the soldering iron around 270 ˚C dur-
ing 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.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK
0
OR DOTTED
LINE WITH MARK
0
ON THE SCHEMATIC DIAGRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB-
LISHED BY SONY.
Note on the AC power adaptor
Use only the supplied AC power adaptor. Do not use
any other AC power adaptor.
Polarity of
the plug
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40 ˚C higher than
ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 ˚C .
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!
• Strong viscosity
Unleaded solder is more viscous (sticky, less prone to flow) than
ordinary solder so use caution not to let solder bridges occur
such as on IC pins, etc.
• Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
Содержание Walkman WM-EX921
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