ICD-ST25 - Sony Audio Service Manual (repair manual). Page 2

2

• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-

aged by heat.

✩

Replacement of IC6001 used in this set requires a special tool.

•

The voltage and waveform of CSP (chip size package) cannot be
measured, because its lead layout is different from that of conven-
tional IC.

•

Lead layouts

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.)

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.

·········································································· 3

2-1. Case Block Assy ··························································· 4
2-2. F-SW Board ·································································· 5
2-3. MAIN Board ································································· 5
2-4. S-SW Board, Microphone Block Assy ························· 6
2-5. Microphone Unit ··························································· 7
2-6. The Cautions At The Time Of A Microphone

Block  Assy ··································································· 8

······································································ 9

4-1. Block Diagrams

– MAIN Section -1 – ·················································· 13
– MAIN Section -2 – ·················································· 14
– PANEL/POWER Section – ······································ 15

4-2. Printed Wiring Board – MAIN Board (Side A) – ······· 16
4-3. Printed Wiring Board – MAIN Board (Side B) – ······· 17
4-4. Printed Wiring Board – F-SW Board – ······················· 18
4-5. Printed Wiring Board – S-SW Board – ······················· 19
4-6. Schematic Diagram – MAIN Board (1/5) – ··············· 20
4-7. Schematic Diagram – MAIN Board (2/5) – ··············· 21
4-8. Schematic Diagram – MAIN Board (3/5) – ··············· 22
4-9. Schematic Diagram – MAIN Board (4/5) – ··············· 23
4-10. Schematic Diagram – MAIN Board (5/5) – ··············· 24
4-11. IC Pin Function Descriptions ······································ 29

5-1. Upper Lid Block ························································· 34
5-2. Case Block ·································································· 35

······································· 36

surface

Lead layout of

conventional IC

CSP (chip size package)