XR-4950X - Sony Car Audio Service Manual (repair manual). Page 2

2

Location of Controls .......................................................

3

2-1. Disassembly Flow ...........................................................

7

2-2. Sub Panel Assy ................................................................

7

2-3. Mechanism Deck (MG-25F-136) ...................................

8

2-4. MAIN Board ...................................................................

8

2-5. Heat Sink (2P) .................................................................

9

3-1. Assembly Flow ................................................................ 10
3-2. Housing ........................................................................... 11
3-3. Arm (Suction) ................................................................. 11
3-4. Lever (LDG-A)/(LDG-B) ............................................... 12
3-5. Gear (LDG-FT) ............................................................... 12
3-6. Guide (C) ......................................................................... 13
3-7. Mounting Position of Capstan/Reel Motor (M901) ....... 13

....................... 14

Tape Deck Section .......................................................... 14
Tuner Section .................................................................. 14

6-1. Note for Printed Wiring Boards and

Schematic Diagrams ....................................................... 15

6-2. Printed Wiring Board – MAIN Board – ......................... 17
6-3. Schematic Diagram – MAIN Board (1/2) – ................... 18
6-4. Schematic Diagram – MAIN Board (2/2) – ................... 19
6-5. Printed Wiring Board – SUB Board – ............................ 20
6-6. Schematic Diagram – SUB Board – ............................... 20
6-7. Printed Wiring Board – KEY Board – ............................ 22
6-8. Schematic Diagram – KEY Board – .............................. 23
6-9. IC Pin Function Description ........................................... 24

7-1. General Section ............................................................... 26
7-2. Front Panel Section ......................................................... 27
7-3. Mechanism Deck Section (MG-25F-136) ...................... 28

............................... 29

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

aged by heat.

• 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.