ICD-ST25VTP - Sony Audio Service Manual (repair manual). Page 2

2

...................................................................

3

2-1.

Disassembly Flow ...........................................................

4

2-2.

Case Block Assy ..............................................................

4

2-3.

F-SW Board .....................................................................

5

2-4.

MAIN Board ....................................................................

5

2-5.

S-SW Board, MICROPHONE Block Assy .....................

6

2-6.

Microphone Unit .............................................................

7

2-7.

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

5-1.

Upper Lid Block .............................................................. 35

5-2.

Case Block ....................................................................... 36

.................................. 37

•

Never reuse a disconnected chip component.

•

Notice that the minus side of a tantalum capacitor may be
damaged 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
conventional IC.

•

Lead layouts

surface

Lead layout of

conventional IC

CSP (chip size package)

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 viscou-s (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.