TABLE OF CONTENTS
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.
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.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK
!
OR DOTTED LINE WITH
MARK
!
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
PUBLISHED BY SONY.
WM-EX621
2
1. SERVICE NOTE
······························································· 3
2. GENERAL
·········································································· 5
3. DISASSEMBLY
3-1. CASE SUB ASSY ·························································· 7
3-2. MAIN BOARD ······························································· 8
3-3. BELT (F4) ······································································· 8
3-4. MOTOR (CAPSTAN/REEL) (M901) ···························· 9
3-5. LID ASSY, CASSETTE ················································· 9
3-6. ORNAMENT, REEL ···················································· 10
3-7. HOLDER (FS) ASSY ··················································· 10
3-8. LEVER (N)/(R) ASSY, PINCH ···································· 11
3-9. HEAD, MAGNETIC (HP901) ······································ 11
4. MECHANICAL ADJUSTMENT
································ 12
5. ELECTRICAL ADJUSTMENT
·································· 12
6. DIAGRAMS
6-1. BLOCK DIAGRAM ····················································· 13
6-2. NOTE FOR PRINTED WIRING BOARDS AND
SCHEMATIC DIAGRAMS ·········································· 14
6-3. IC BLOCK DIAGRAMS ·············································· 14
6-4. SCHEMATAC DIAGRAM – MAIN BOARD – ·········· 15
6-5. PRINTED WIRING BOARD – MAIN BOARD – ······ 16
6-6. IC PIN FUNCTION ······················································ 17
7. EXPLODED VIEWS
7-1. CABINET BLOCK ······················································· 19
7-2. MAIN BOARD BLOCK ·············································· 20
7-3. MACHANISM BLOCK – 1 ········································· 21
7-4. MACHANISM BLOCK – 2 ········································· 22
8. ELECTRICAL PARTS LIST
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