Sony wm fx 421 service manual

Page 2

TABLE OF CONTEMTS

§$tion me 128$
SECTION 1 GENERAL

SECTION 2 DISASSEMBLY
2-]. Cabinet (Rear) Assembly.
2-2. Mechanism Deck and Main Board
2-3. Main Board
2-4. Cassette Lid
2-5. Display Board
2~6. Note for Installatio

«murmur-k

SECTION 3 ADJUSTMENTS
3-li Mechanical Adjustments .....
3-2i Electrical Adjustments

SECTION 4 DIAGRAMS
4-1i Printed Wiring Board
4-2. Schematic Diagram H
43. 1C Pin Function
IC401 uPD1724GB ........................................................... 21

13
17

SECTION 5 EXPLODED VIEWS
5-1, Cabinet and Board Section ....................
5-2. Mechanism Section (MF-WMFX305-43)

22
23

SECTION 6 ELECTRICAL PARTS LIST ............................ 2A .

HOW TO CHANGED THE CERAMIC FILTERS

This model is used two ceramic filters of CF2, X2. You must used
same type of color marked ceramic filters in order to meet same
specifications.

Therefore, the ceramic filter must changed two pieces together since
its supply two pieces in one package as a spare parts.

color mark
color mark Center Frequency
CF2 red 10.70MHz
blue 10. 67MHz
color mark

orange 10,73MHz
X2 black 10.64MHZ
white 10.76MHZ

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 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.