Table Of Contents - Sony WM-GX780 Service Manual

WM-GX780/GX788
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
PUBLISHED BY SONY.
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

TABLE OF CONTENTS

1. SERVICE NOTE
······························································· 3
2. GENERAL
·········································································· 5
3. DISASSEMBLY
3-1. Case Block Assy ····························································· 6
3-2. Button Rec, Button Assy ················································· 7
3-3. Cassette Lid Assy ···························································· 7
3-4. Ornament Block Assy Reel, Flexible Retainer ··············· 8
3-5. MAIN Board, Belt (F0) ·················································· 8
3-6. Motor (M901) ································································· 9
3-7. Bracket (cassette) Assy, Holder (FA) Assy ····················· 9
3-8. Pinch Lever (RA) Assy, Pinch Lever (NA) Assy ·········· 10
3-9. Magnetic Head (HP901) ··············································· 10
4. MECHANICAL ADJUSTMENT
5. ELECTRICAL ADJUSTMENT
6. DIAGRAMS
······································································ 12
6-1. Block Diagram ······························································ 13
6-2. Printed Wiring Board (Side A) ······································ 14
6-3. Printed Wiring Board (Side B) ······································ 15
6-4. Schematic Diagram (1/2) ·············································· 16
6-5. Schematic Diagram (2/2) ·············································· 17
6-6. IC Block Diagrams ······················································· 18
6-7. IC Pin Function Discription ·········································· 19
7. EXPLODED VIEWS
7-1. Case Section ·································································· 21
7-2. Main Section ································································· 22
7-3. Mechanism Deck Section (MF-WMGX788-162) ········ 23
8. ELECTRICAL PARTS LIST
································ 11
·································· 11
······································· 24
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.