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Sony XR-4950X Service Manual

Fm/am cassette car stereo
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Ver 1.0 2001.04
Cassette player section
Tape track
Wow and flutter
Frequency response
Signal-to-noise ratio
Tuner section
Tuning range
Aerial terminal
Intermediate frequency
Usable sensitivity
Signal-to-noise ratio
Harmonic distortion at 1 kHz
Frequency response
Tuning range
Aerial terminal
Intermediate frequency
Power amplifier section
Speaker impedance
Maximum power output 50 W × 4 (at 4 ohms)
Sony Corporation
e Vehicle Company
C 2001.4
Shinagawa Tec Service Manual Production Group
4-track 2-channel stereo
0.08 % (WRMS)
30 – 18,000 Hz
58 dB
87.5 – 108.0 MHz
External aerial connector
10.7 MHz/450kHz
8 dBf
75 dB at 400 kHz
66 dB (stereo),
72 dB (mono)
0.6 % (stereo),
0.3 % (mono)
35 dB at 1 kHz
30 – 15,000 Hz
531 – 1,602 kHz
External aerial connector
10.7 MHz/450 kHz
30 µV
Speaker outputs
(sure seal connectors)
4 – 8 ohms
Model Name Using Similar Mechanism
Tape Transport Mechanism Type
Audio output
Power aerial relay control
Power amplifier control
Telephone ATT control
Bass ±9 dB at 100 Hz
Tone controls
Treble ±9 dB at 10 kHz
Power requirements
12 V DC car battery
(negative earth)
Approx. 178 × 50 × 183 mm
Approx. 182 × 53 × 162 mm
Mounting dimensions
Approx. 1.2 kg
Supplied accessories
Parts for installation and
connections (1 set)
Front panel case (1)
Design and specifications are subject to change
without notice.
AEP Model


Table of Contents

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  Summary of Contents for Sony XR-4950X

  • Page 1 XR-4950X SERVICE MANUAL AEP Model Ver 1.0 2001.04 Model Name Using Similar Mechanism Tape Transport Mechanism Type MG-25F-136 SPECIFICATIONS Cassette player section General Tape track 4-track 2-channel stereo Outputs Audio output Wow and flutter 0.08 % (WRMS) Power aerial relay control Frequency response 30 –...
  • Page 2: Table Of Contents

    XR-4950X TABLE OF CONTENTS Notes on chip component replacement • Never reuse a disconnected chip component. • Notice that the minus side of a tantalum capacitor may be dam- GENERAL aged by heat. Location of Controls ............3 Flexible Circuit Board Repairing DISASSEMBLY •...
  • Page 3: General

    XR-4950X SECTION 1 This section is extracted from instruction manual. GENERAL Location of controls OPEN D-BASS MENU MODE SOURCE -SEEK/AMS SOUND ENTER XR-4950X Refer to the pages listed for details. 1 MENU button qs Reset button (located on the front side...
  • Page 4 B нeкотоpыx aвтомобиляx японcкого пpоизводcтвa этот aппapaт ycтaновить нeвозможно. B этом cлyчae You may not be able to install this unit in some makes of Japanese cars. In such a case, consult your Sony dealer. обpaтитecь к cвоeмy дилepy Sony.
  • Page 5: Reset Button

    XR-4950X Подсоединение Connections Предостережение Caution • Данная автомагнитола предназначена для подключения только к 12-вольтному аккумулятору • This unit is designed for negative earth 12 V DC operation only. постоянного тока с отpицaтeльным заземлением. • Do not get the wires under a screw, or caught in moving parts (e.g. seat railing).
  • Page 6: Connection Example

    XR-4950X Connection example Пример подсоединения from car aerial от автомобильной антенны REMOTE IN Fuse (10 A) AUDIO OUT Rotary commander RM-X4S (not supplied) Предохранитель (LINE OUT) REAR Вращающийся дистанционный (10 А) переключатель RM-X4S (не прилагается) Insert with the cord upwards.
  • Page 7: Disassembly

    XR-4950X SECTION 2 DISASSEMBLY • This set can be disassembled in the order shown below. 2-1. DISASSEMBLY FLOW FRONT PANEL SECTION Note: Illustration of disassembly is omitted. 2-2. SUB PANEL ASSY (Page 7) 2-3. MECHANISM DECK (MG-25F-136) (Page 8) 2-4. MAIN BOARD (Page 8) 2-5.
  • Page 8: Mechanism Deck (Mg-25F-136)

    XR-4950X 2-3. MECHANISM DECK (MG-25F-136) 3 screw (PTT2.6 × 6) 4 mechanism deck (MG-25F-136) 2 connector (CN351) 1 flexible board (CN301) 2-4. MAIN BOARD 3 rubber cap (25) 1 three screws (PTT2.6 × 8) 2 three ground point screws 4 main board...
  • Page 9: Heat Sink (2P)

    XR-4950X 2-5. HEAT SINK (2P) 1 two screws (PTT2.6 × 8) 2 two screws (PTT2.6 × 12) 3 heat sink (2P) 1 two screws (PTT2.6 × 8)
  • Page 10: Assembly Of Mechanism Deck

    XR-4950X SECTION 3 ASSEMBLY OF MECHANISM DECK • This set can be assembled in the order shown below. 3-1. ASSEMBLY FLOW 3-2. HOUSING (Page 11) 3-3. ARM (SUCTION) (Page 11) 3-4. LEVER (LDG-A)/(LDG-B) (Page 12) 3-5. GEAR (LDG-FT) (Page 12) 3-6.
  • Page 11: Housing

    XR-4950X Note: Follow the assembly procedure in the numerical order given. 3-2. HOUSING 7 Hold the hanger by bending the claw. 5 Fit projection on C part. 1 Install the catch to the hanger. 2 Install the hanger onto two claws of the housing.
  • Page 12: Lever (Ldg-A)/(Ldg-B)

    XR-4950X 3-4. LEVER (LDG-A) / (LDG-B) shaft A shaft A shaft B shaft B shaft C 1 Fit the lever (LDG-A) on 3 type-E stop ring 2.0 shafts A – C and install it. 2 Fit the lever (LDG-B) on shafts A and B and install it.
  • Page 13: Guide (C)

    XR-4950X 3-6. GUIDE (C) 2 guide (C) 1 three claws 3-7. MOUNTING POSITION OF CAPSTAN/REEL MOTOR (M901) two precision screws (P2 × 2) capstan/reel motor (M901) Note: Mount the motor so that the angle between of the motor and the hole for the becomes 30 °...
  • Page 14: Mechanical Adjustments

    XR-4950X SECTION 4 SECTION 5 MECHANICAL ADJUSTMENTS ELECTRICAL ADJUSTMENTS 1. Clean the following parts with a denatured-alcohol-moistened TAPE DECK SECTION 0 dB=0.775 V swab: playback head pinch roller Tape Speed Adjustment rubber belt capstan Setting: idler 2. Demagnetize the playback head with a head demagnetizer.
  • Page 15: Diagrams

    XR-4950X SECTION 6 DIAGRAMS 6-1. NOTE FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS Note on Printed Wiring Board: Note on Schematic Diagram: • All capacitors are in µF unless otherwise noted. pF: µµF • X : parts extracted from the component side.
  • Page 16 XR-4950X MEMO...
  • Page 17: Printed Wiring Board - Main Board

    XR-4950X 6-2. PRINTED WIRING BOARD – MAIN Board – • Semiconductor Location Ref. No. Location J331 AUDIO OUT (REMOTE IN) REAR F-13 (FM/AM ANTENNA) D351 J-13 MAIN BOARD D352 H-13 D501 JW90 JW88 JW87 JW86 D551 G-13 C183 C752 C272...
  • Page 18: Schematic Diagram - Main Board (1/2)

    XR-4950X 6-3. SCHEMATIC DIAGRAM – MAIN Board (1/2) – • • See page 15 for Waveforms. See page 21 for IC Block Diagrams. (Page 19)
  • Page 19: Schematic Diagram - Main Board (2/2)

    XR-4950X 6-4. SCHEMATIC DIAGRAM – MAIN Board (2/2) – • See page 21 for IC Block Diagrams. (Page (Page 18)
  • Page 20: Printed Wiring Board - Sub Board

    XR-4950X 6-5. PRINTED WIRING BOARD – SUB Board – 6-6. SCHEMATIC DIAGRAM – SUB Board – LED801 K1 S2 K2 A1 S1 A2 LSW801 (Page 23) (Page 19) (Page 17) (Page 22)
  • Page 21 XR-4950X • IC Block Diagrams – MAIN Board – IC301 CXA2509AQ-T4 IC351 LB1930M-TLM IC331 TDA7402TR BUFFER 33 32 31 24 23 OUT1 MOTOR CONTROL DRIVE CIRCUIT MIXER CIRCUIT 24dB OUT2 120µ/70µ BUFFER MONO- MONO- MONO- MONO- MONO- MONO- + –...
  • Page 22: Printed Wiring Board - Key Board

    XR-4950X 6-7. PRINTED WIRING BOARD – KEY Board – LED901 – 904 LSW912 – 917 R939 R930 • Semiconductor Location (Page 20) Ref. No. Location Ref. No. Location D901 H-11 LED901 D902 G-10 LED902 D903 G-10 LED903 D904 G-10 LED904...
  • Page 23: Schematic Diagram - Key Board

    XR-4950X 6-8. SCHEMATIC DIAGRAM – KEY Board – • See page 15 for Waveform. (Page...
  • Page 24: 6-9. Ic Pin Function Description

    XR-4950X 6-9. IC PIN FUNCTION DESCRIPTION • MAIN BOARD IC501 MN101C49KTA2 (SYSTEM CONTROLLER) Pin No. Pin Name Description Pin No. Pin Name Description VREF Reference voltage (0V) input terminal (for A/D converter) ACC IN Accessory detection signal input “L”: accessory on...
  • Page 25 XR-4950X Pin No. Pin Name Description Rotation detection signal input from supply reel sensor and take-up reel sensor on the deck mechanism POS3 Tape position (EJECT/FF/REW/ POS0: “L”: EJECT mode, “H”: others mode POS2 REV/FWD mode) detection signal POS1: “L”: FF and FWD mode, “H”: others mode input from the tape operation switch POS2: “L”: REW mode, “H”: others mode...
  • Page 26: Exploded Views

    XR-4950X SECTION 7 EXPLODED VIEWS NOTE: • -XX and -X mean standardized parts, so they • Items marked “*” are not stocked since they may have some difference from the original are seldom required for routine service. Some one. delay should be anticipated when ordering •...
  • Page 27: 7-2. Front Panel Section

    XR-4950X 7-2. FRONT PANEL SECTION not supplied (KEY board) LCD901 Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark 3-040-980-01 BUTTON (SOURCE) * 60 3-040-997-01 PLATE (LCD), GROUND 3-040-981-11 KNOB (VOL) * 61 3-041-371-11 SHEET (REFLECTOR) 3-041-005-11 BUTTON (D) (D-BASS)
  • Page 28: Mechanism Deck Section (Mg-25F-136)

    XR-4950X 7-3. MECHANISM DECK SECTION (MG-25F-136) HP901 M901 not supplied Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark A-3291-667-A CLUTCH (FR) ASSY 3-933-346-01 CATCHER * 152 3-019-130-01 LEVER (LDG-A) 3-933-344-01 GUIDE (C) * 153 3-019-131-01 LEVER (LDG-B)
  • Page 29: Electrical Parts List

    XR-4950X SECTION 8 ELECTRICAL PARTS LIST NOTE: When indicating parts by reference • Due to standardization, replacements in the • Items marked “*” are not stocked since they number, please include the board. parts list may be different from the parts speci- are seldom required for routine service.
  • Page 30 XR-4950X MAIN Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark R935 1-216-812-11 METAL CHIP 1/16W C109 1-163-227-11 CERAMIC CHIP 10PF 0.5PF C110 1-163-227-11 CERAMIC CHIP 10PF 0.5PF R938 1-216-809-11 METAL CHIP 1/16W C111 1-163-227-11 CERAMIC CHIP 10PF 0.5PF...
  • Page 31 XR-4950X MAIN Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark C508 1-164-161-11 CERAMIC CHIP 0.0022uF 10% 100V D614 8-719-970-02 DIODE 1SR139-400T-32 C509 1-163-809-11 CERAMIC CHIP 0.047uF D621 8-719-056-77 DIODE UDZ-TE-17-3.9B D622 8-719-404-50 DIODE MA111-TX C511 1-163-021-11 CERAMIC CHIP 0.01uF...
  • Page 32 XR-4950X MAIN Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark < TRANSISTOR > R304 1-216-077-00 RES-CHIP 1/10W R305 1-216-001-00 METAL CHIP 1/10W Q171 8-729-920-21 TRANSISTOR DTC314TK-T-146 R306 1-216-105-00 RES-CHIP 220K 1/10W Q181 8-729-920-21 TRANSISTOR DTC314TK-T-146 R331...
  • Page 33 XR-4950X MAIN Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark R562 1-208-806-11 RES-CHIP 0.5% 1/10W 1-676-603-12 SUB BOARD R563 1-216-025-11 RES-CHIP 1/10W ********** R564 1-216-025-11 RES-CHIP 1/10W 1-792-195-11 CABLE, FLEXIBLE FLAT (14 CORE) R570 1-216-097-11 RES-CHIP...
  • Page 34 XR-4950X Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark PARTS FOR INSTALLATION AND CONNECTIONS ************************************** X-3373-602-1 FRAME ASSY X-3366-405-1 SCREW ASSY (EXP), FITTING 3-040-979-01 COLLAR 3-934-325-01 SCREW, +K (5X8) TAPPING 3-233-644-01 SPRING, FITTING SCREW, FITTING BUSHING ×...
  • Page 35 XR-4950X MEMO...
  • Page 36 XR-4950X REVISION HISTORY Clicking the version allows you to jump to the revised page. Also, clicking the version at the upper right on the revised page allows you to jump to the next revised page. Ver. Date Description of Revision...