Sony XR-4759RDS User manual

MICROFILM
UK Model
SERVICE MANUAL
FM/MW/LW CASSETTE CAR STEREO
SPECIFICATIONS
Model Name Using Similar Mechanism XR-3740
Tape Transport Mechanism Type MG-52A-135
XR-4758RDS/4759RDS
Photo: XR-4759RDS

– 2 –
TABLE OF CONTENTS
1. GENERAL
Location of Controls........................................................ 3
2. DISASSEMBLY ......................................................... 4
3. ASSEMBLY OF MECHANISM DECK ........... 6
4. MECHANICAL ADJUSTMENTS ....................... 12
5. ELECTRICAL ADJUSTMENTS
Test Mode ........................................................................ 12
Tape Deck Section ........................................................... 13
Tuner Section................................................................... 13
6. DIAGRAMS
6-1. IC Pin Function Description............................................ 16
6-2. Printed Wiring Boards – MAIN Section – ..................... 18
6-3. Schematic Diagram – MAIN Section –........................... 21
6-4. Printed Wiring Board – KEY Section – ......................... 27
6-5. Schematic Diagram – KEY Section – ............................ 29
7. EXPLODED VIEWS ................................................ 34
8. ELECTRICAL PARTS LIST................................ 38
SERVICING NOTES
Flexible Circuit Board Repairing
•Keep the temperature of the 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 .
Notes on chip component replacement
•Never reuse a disconnected chip component.
•Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.

– 3 –
SECTION 1
GENERAL This section is extracted
from instruction manual.

– 4 –
Note: Follow the disassembly procedure in the numerical order given.
FRONT PANEL ASS’Y
SECTION 2
DISASSEMBLY
1 Push the button
(release).
A
2 Remove the front panel ass’y
to the direction of the arrow A .
COVER ASS’Y
2
1
3 cover ass’y
1
2

– 5 –
MAIN BOARD, HEAT SINK
1 three screws
(PTT2.6 × 6)
5 screw
(PTT2.6 × 6)
6 mechanism deck
(MG-52A-135)
4 flexible flat cable
(CN351)
1 three screws
(PTT2.6 × 6)
2 sub panel
3 connector
(CN352)
1 screw
(PTT2.6 × 6)
3 main board
1 two screws
(PTT2.6 × 6)
2 two ground point
screws
4 six screws
(PTT2.6 × 8)
SUB PANEL, MECHANISM DECK (MG-52A-135)

– 6 –
SECTION 3
ASSEMBLY OF MECHANISM DECK
Note: Follow the assembly procedure in the numerical order given.
ALIGNMENT OF FRONT SWITCH
GEAR (LDGE)
2 Install the gear (LDG-E).
1 Align hole as shown in the figure.
1 Align ¢ mark on the rotary switch
the position shown in the figure.
chassis (S) ass’y
2 Align hole in the gear (LDG-D) with the
position shown in the figure.
hole

– 7 –
CHASSIS (S) ASS’Y
1. Align ¢ mark on the rotary switch with
hole in the lever (mode).
2. Fit on positions A , B and C and install
the lever (mode).
LEVER (MODE)
hole in lever (mode)
¢ mark on rotary switch
lever (mode)
rotary switch
A
B
C
2 screw (PS2 × 4)
1 chassis (S) ass’y
2 screw (PS2 × 4)

– 8 –
5 step screw (HP)
5 step screw (HP)
2 Fit shaft in groove.
ATS lever
1 Fit in groove.
3 Press the ATS lever.
4 Position the head plate sub
ass’y as shown in the figure.
groove
LEVER (PINCH SELECTION)
HEAD PLATE ASS’Y
1 Align.
2 lever (pich selection)

– 9 –
LEVER (PINCH) ASS’Y
1 Fit shaft of the lever (Pinch) ass’y
in hole on the chassis (M) ass’y and
install the lever (pinch) ass’y.
2 two polyethylene washers
shaft
shaft
B
C
C
B
shaft A
3 Install the spring (pinch press) to shaft A .
Set the ends of spring to B and C .
HOUSING
2 Install the hanger on to
two claws of the housing.
1 Install the catch to the hanger.
7 Holder the hanger by bending the claw.
A part
B part
C part
D part
8 Holder the hanger by
bending the claw.
3 Put the housing
under A part.
4 Fit claw on B part.
6 Fit projections on D part.
5 Fit projections on C part.
hanger

– 10 –
ARM (SUCTION)
1 Fit the lever (LDG-A)
on shaft A – C and install it.
shaft A
shaft B
shaft C
3 two type-E stop ring 2.0
2 Fit the lever (LDG-B)
on shafts A and B and
install.
shaft A
shaft B
LEVER (LDG-A) / (LDG-B)
2 Move the arm (suction) in the arrow
direction and fit on projection.
1 Fit the arm (suction) on the shaft.
projection