MDR-RF950RK

SERVICE MANUAL

Ver 1.0 1998. 06

US Model Canadian Model

MDR-RF950 TMR-RF950R

MDR-RF950RK is composed of the following models. As for the service manual, it is issued for each component model, then, please refer to it. Headphones Transmitter MDR-RF950 TMR-RF950R

SPECIFICATIONS

General Carrier frequency Channel Modulation Frequency response Headphones Power source Mass Transmitter RF power Power source Audio input Dimensions Mass 913.0 915.0 MHz Ch1, Ch2, Ch3 FM stereo 18 22,000 Hz DC3V: 2 R6 (size AA) battery or 2 supplied NC-AA-HJ Ni-Cd rechargeable battery Approx. 265 g (9.4 oz.) incl. Ni-Cd batteries
ACCESSORIES & PACKING MATERIALS
Ref. No. ! ! Part No. 1-465-948-21 1-506-652-11 1-528-803-41 1-575-195-11 3-864-034-11 Description ADAPTOR, AC (AC-S901) ADAPTOR, PLUG BATTERY, NICKEL CADMIUM CORD, CONNECTION MANUAL, INSTRUCTION (ENGLISH, SPANISH) (US)
3-864-034-21 MANUAL, INSTRUCTION (ENGLISH,FRENCH) (Canadian)
Less than 94 dBV/m at 3 m DC9 V: supplied AC power adaptor phono jacks/stereo mini jack Approx. 120 mm dia 290 mm (43/4 111/2 in.) (w/h) Approx. 155 g (5.5 oz.)
The components identified by mark ! or dotted line with mark ! are critical for safety. Replace only with part number specified.
Les composants identifis par une marque ! sont critiques pour la scurit. Ne les remplacer que par une pice portant le numro spcifi.
Supplied Ni-Cd rechargeable batteries Model name NC-AA (HJ) Voltage 1.2 V Capacity 600 mAh Battery life Battery Sony alkaline battery SG (LR6) Sony battery SR (R6P) * at 1 kHz, 1 mW + 1 mW output Design and specifications are subject to change without notice. Approx. hours* 60 30
WIRELESS STEREO HEADPHONE SYSTEM

MICROFILM

Sony Corporation

9-924-926-11

Personal A&V Products Company
98F057022-1 Printed in Singapore 1998. 6 Published by Quality Engineering Dept. (Shibaura)

MDR-RF950

SERVICE MANUAL

Ver 1.0 1998. 06

US Model Canadian Model
MDR-RF950 is headphones in MDR-RF950RK.
TABLE OF CONTENTS 1. GENERAL... 2 DISASSEMBLY.. 3 ELECTRICAL ADJUSTMENTS

SPECIFICATIONS

3-1. Checking/Adjusting Receiving Frequency. 5 3-2. Checking/Adjusting Degree of Modulation of Main Carrier (L + R).. 6 3-3. Checking/Adjusting Separation.. 7

DIAGRAMS

4-1. Printed Wiring Boards... 11 4-2. Schematic Diagram.. 13
EXPLODED VIEWS.. 15 ELECTRICAL PARTS LIST. 17
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.
WIRELESS STEREO HEADPHONES

MICROFILM

This section is extracted from instruction manual.

SECTION 1 GENERAL

SECTION 2 DISASSEMBLY
This set can be disassembled in the order shown below. SET FRONT PLATE ASSY RX-BASE BOARD HANGER COVER (L) SW BOARD
Note: Follow the disassembly procedure in the numerical order given.

FRONT PLATE ASSY

4 Remove two solders of driver lead.

3 front plate assy

2 three screws (P2 6)

1 ear pad

RX-BASE BOARD
3 Remove four solders of leads. 1 two screws (P2 10)

2 hanger cover (R)

4 RX-BASE board

1 two screws (P2 6)

3 Remove three solders of leads.

SW BOARD

1 two head bands

2 screw (P2 6)

3 switch support 5 SW board

4 head cushion assy

HANGER COVER (L)

2 hanger cover (L)

3 Remove two solders of battery lead. 1 two screws (P2 10)
SECTION 3 ELECTRICAL ADJUSTMENTS
Note: 1. The adjustments should be performed in the order given. 2. The transmitter (TMR-RF950R) already checked and adjusted should be used.
3-1. Receiving Frequency Check and Adjustment

Preparation:

AF OSC ATT + + TMR-RF950R 600 Transmitter 5m MDR-RF950 Headphones
AUDIO IN (Lch) 1 kHz 316 mVrms
[RX-BASE board] Conductor Side

DC voltmeter

oscilloscope
Procedure: 1. Set the channel of the transmitter to CH2. 2. Turn OFF the noise filter switch on the transmitter. 3. Enter 1 kHz 316 mVrms signal only to the Lch on the transmitter. 4. Place the transmitter away from the headphone (MDR-RF950) more than 5 m. 5. Set the volume control (RV301) on the RX-BASE board to the minimum position. 6. Set the tuning control (RV302) on the RX-BASE board to the center position. 7. Connect a DC voltmeter and an oscilloscope between IC301 pin @ and ground on the RX-BASE board. 8. After confirming that demodulated 1 kHz waveform (about 13 mV) appears on the oscilloscope, check that the DC voltmeter indicates DC1 V to 1.2 V. 9. If demodulated 1 kHz waveform does not appear on the oscilloscope, or if the voltage is out of the specified value, adjust the air-core coil (L301) on the RX-BASE board so that the demodulated 1 kHz waveform appears on the oscilloscope, and under this condition, adjust finely the air-core coil (L301) so that the DC voltmeter indicates DC1.1 V. 10. Finally, check that signals are received when the channel is changed over to CH1/CH3 on the transmitter, then when the tuning control (RV302) on the RX-BASE board is rotated. Adjustment Location: RX-BASE board (See page 9.)

3-2. Degree of Modulation of Main Carrier (L + R) Check and Adjustment
AF OSC ATT + + TMR-RF950R 600 Transmitter MDR-RF950 Headphones

AC voltmeter

Procedure: 1. Set the channel of the transmitter to CH2. 2. Turn OFF the noise filter switch on the transmitter. 3. Enter 1 kHz 316 mVrms signal only to the Lch on the transmitter. 4. Set the volume control (RV301) on the RX-BASE board to the minimum position. 5. Connect an AC voltmeter and an oscilloscope between IC 301 pin @ and ground on the RX-BASE board. 6. Rotating the tuning control (RV302) on the RX-BASE board, receive signals. 7. After confirming that demodulated 1 kHz waveform appears on the oscilloscope, check that the AC voltmeter indicates 12 mVrms to 15 mVrms. 8. If out of the specified value, rotate RV404 on the TX-BASE board in the transmitter (TMR-RF950R) so as to attain 13.5 mVrms. Adjustment Location: TX-BASE board in the transmitter (TMR-RF950R) (See page 8.)
3-3. Separation Check and Adjustment
AUDIO IN (Lch or Rch) 1 kHz 316 mVrms
Procedure: 1. Set the channel of the transmitter to CH2. 2. Turn OFF the noise filter switch on the transmitter. 3. Enter 1 kHz 316 mVrms signal only to the Lch on the transmitter. 4. Connect an AC voltmeter and an oscilloscope to the Lch speaker output (both ends of MDD01) on the RX-BASE board. 5. Rotating the tuning control (RV302) on the RX-BASE board, receive signals. 6. Adjust the volume control (RV301) on the RX-BASE board so that the Lch speaker output (both ends of MDD01) on the RX-BASE board becomes 155 mVrms. 7. Connect an AC voltmeter and oscilloscope to the Rch speaker output (both ends of MDD02) and measure voltage. 8. Check that a difference in speaker output level between Lch and Rch (i. e., separation) is over 20 dB. If not over 20 dB, rotate RV303 on the RX-BASE board to minimize the Rch output, then reconfirm that a difference in speaker output level between Lch and Rch is over 20 dB. 9. Enter 1kHz 316 mVrms signal only to the Rch on the transmitter. 10. Adjust the volume control (RV301) on the RX-BASE board so that the Rch speaker output (voltage across MDD02) on the RX-BASE board become 155 mVrms. 11. Connect an AC voltmeter and oscilloscope to the Lch speaker output (both ends of MDD01) and measure voltage. 12. Check that a difference in speaker output level between Lch and Rch (i.e., separation) is over 20 dB. Adjustment Location: RX-BASE board (See page 9.)

Adjustment Location: Transmitter (TMR-RF950R)
[TX-BASE board] Component Side
RV404 Degree of Modulation of Main Carrier (L + R) Adjustment

ER LT FI ON E IS NO FF O

J402 (Rch)

J403 (Lch)

AN CH NE 2 L

Headphone (MDR-RF950)

[RX-BASE board] Component Side

RV302 TUNING

MAX RV301 VOL MIN
L301 Receiving Frequency Adjustment
RV303 Separation Adjustment

SECTION 4 DIAGRAMS

IC Block Diagrams IC301 CXA1611N-T4

IC302 LA4533M

PWR 1 R-IN 2 GND 3 L-IN 4

POWER SWITCH AMP

10 MUTE 9 R-OUT

8 GND 7 L-OUT

AMP REG VCC

SECTION 5 EXPLODED VIEWS

NOTE: -XX and -X mean standardized parts, so they may have some difference from the original one. Color Indication of Appearance Parts Example: KNOB, BALANCE (WHITE). (RED) Parts Color Cabinet's Color Items marked * are not stocked since they are seldom required for routine service. Some delay should be anticipated when ordering these items. The mechanical parts with no reference number in the exploded views are not supplied.
(1) HEADPHONE (R) SECTION
Remark Ref. No. 13 Part No. 4-999-767-01 7-685-106-19 4-966-791-11 4-966-792-11 3-318-203-62 Description HANGER (R) SCREW +P 2X10 TYPE2 NON-SLIT STOPPER (UPPER) STOPPER (LOWER) SCREW (B1.7X4), TAPPING Remark

Ref. No. 5 * * 8

Part No. 4-971-700-01 X-4950-190-1 4-999-774-01 4-999-773-01 4-999-769-11
Description PAD, EAR PLATE (R) ASSY, FRONT REGISTER, HOUSING HOUSING (R) COVER (R), HANGER
A-4542-518-A RX-BASE BOARD, COMPLETE 4-210-255-01 SUPPORT, SWITCH 1-670-527-11 SW BOARD
14 7-685-104-19 SCREW +P 2X6 TYPE2 NON-SLIT MDD02 1-505-117-21 DRIVER (R-CH)
(2) HEADPHONE (L) SECTION 57 63
Ref. No. 60 Part No. 4-999-771-01 4-978-518-02 4-978-519-01 3-318-203-62 4-966-792-11 4-966-791-11 4-999-765-01 7-685-106-19 4-999-766-11 4-999-766-21 Description SUSPENDER BASE, SUSPENDER CUSHION, HEAD SCREW (B1.7X4), TAPPING STOPPER (LOWER) STOPPER (UPPER) BAND, HEAD SCREW +P 2X10 TYPE2 NON-SLIT HANGER (L) (US) HANGER (L) (Canadian) Remark Ref. No. 69 MDD01
Part No. 4-210-257-01 4-210-256-01 4-999-770-11 4-999-768-01 4-999-772-01 4-999-774-01 X-4950-189-1 4-971-700-01 7-685-104-19 1-505-117-21
Description TERMINAL (-), BATTERY TERMINAL (+), BATTERY LID, BATTERY CASE COVER (L), HANGER HOUSING (L) REGISTER, HOUSING PLATE (L) ASSY, FRONT PAD, EAR SCREW +P 2X6 TYPE2 NON-SLIT DRIVER (L-CH)

Remark

4-210-258-01 TERMINAL (MIDWAY), BATTERY
SECTION 6 ELECTRICAL PARTS LIST
NOTE: Due to standardization, replacements in the parts list may be different from the parts specified in the diagrams or the components used on the set. -XX and -X mean standardized parts, so they may have some difference from the original one. RESISTORS All resistors are in ohms. METAL: Metal-film resistor. METAL OXIDE: Metal oxide-film resistor. F: nonflammable Items marked * are not stocked since they are seldom required for routine service. Some delay should be anticipated when ordering these items. SEMICONDUCTORS In each case, u: , for example: uA. : A. uPA. : PA. uPB. : PB. uPC. : PC. uPD. : PD. CAPACITORS uF: F COILS uH: H

RX-BASE

When indicating parts by reference number, please include the board.

Ref. No.

Part No.

Description

Ref. No. L2 L3 L4 L5 L6
Part No. 1-469-237-21 1-414-665-11 1-414-665-11 1-414-660-11
Description INDUCTOR 0.68uH INDUCTOR CHIP 12nH INDUCTOR CHIP 12nH INDUCTOR CHIP 4.7nH
FE BOARD ******** (Included in RX-BASE BOARD, COMPLETE) < CAPACITOR >
1-414-660-11 INDUCTOR CHIP 4.7nH < TRANSISTOR >
C1 C2 C3 C4 C5 C6 C8 C9 C10 C12 C13 C14 C15 C16 C17 C20 C21 C23 C24 C28 C30 C39 C40 C41 C43 C44
1-162-906-11 1-162-927-11 1-162-964-11 1-162-908-11 1-162-918-11 1-162-964-11 1-162-910-11 1-162-920-11 1-162-905-11 1-162-915-11 1-162-905-11 1-162-925-11 1-162-927-11 1-162-906-11 1-162-964-11 1-162-964-11 1-162-964-11 1-162-906-11 1-162-906-11 1-162-917-11 1-162-921-11 1-162-964-11 1-162-909-11 1-162-910-11 1-162-964-11
CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP
1.5PF 100PF 0.001uF 3PF 18PF 0.001uF 5PF 27PF 1PF 10PF 1PF 68PF 100PF 1.5PF 0.001uF 0.001uF 0.001uF 1.5PF 1.5PF 15PF 33PF 0.001uF 4PF 5PF 0.001uF 100PF
0.25PF 5% 10% 0.25PF 5% 10% 0.25PF 5% 0.25PF 0.5PF 0.25PF 5% 5% 0.25PF 10% 10% 10% 0.25PF 0.25PF 5% 5% 10% 0.25PF 0.25PF 10% 5%
50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V 50V

Q1 Q3 Q4

8-729-046-22 FET 3SK240 (TE85L) 8-729-230-81 TRANSISTOR 2SC3606 8-729-232-73 TRANSISTOR 2SC4320 (TE85L) < RESISTOR >
R1 R4 R5 R7 R8 R10 R11 R12
1-216-845-11 1-216-853-11 1-216-845-11 1-216-809-11 1-218-293-11
METAL CHIP METAL CHIP METAL CHIP METAL CHIP RES,CHIP
100K 470K 100K 100 24K 100K 120 100

5% 5% 5% 5% 5% 5% 5% 5%

1/16W 1/16W 1/16W 1/16W 1/16W 1/16W 1/16W 1/16W
1-216-845-11 METAL CHIP 1-216-810-11 METAL CHIP 1-216-809-11 METAL CHIP < CAPACITOR >

THC1 THC2 THC3

1-104-511-51 CERAMIC 1-111-231-43 CERAMIC 1-111-231-43 CERAMIC

0.001uF 2PF 99% 2PF 99%

< SAW RESONANTOR > X1 1-767-906-11 RESONANTOR, SAW ************************************************************ * A-4542-518-A RX-BASE BOARD, COMPLETE ************************ (Including FE BOARD) < CAPACITOR > C301 C302 C303 C306 C307 C309 C310 1-126-154-11 1-164-489-11 1-163-239-11 1-163-037-11 1-163-121-11 ELECT CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP CERAMIC CHIP 47uF 0.22uF 33PF 0.022uF 150PF 4.7uF 0.1uF 20% 10% 5% 10% 5% 20% 10% 6.3V 16V 50V 25V 50V 35V 25V

20% 5% 10% 10% 20% 20% 20%
16V 10% 50V 0.25PF 50V 5% 50V 10% 50V 20% 5% 5% 10% 10% 10% 5% 10% 16V 50V 50V 50V 50V 16V 16V 50V 50V
< CERAMIC FILTER > CF301 CF302 1-577-588-11 FILTER, CERAMIC 1-567-163-11 FILTER, CERAMIC < DIODE > D301 D302 D303 8-719-045-99 DIODE RD2.2M-T1B 8-719-002-81 DIODE 1T363 8-719-066-69 LED BR2434D (POWER) < IC > IC301 IC302 IC303 IC304 8-752-066-93 8-759-802-75 8-759-195-02 8-759-096-87 IC IC IC IC CXA1611N-T4 LA4533M TC7S86F-TE85L TC7WU04FU(TE12R)
< SHORT > JR301 JR302 JR303 JR304 JR305 JR306 JR308 JR309 JR310 1-216-296-00 1-216-296-00 1-216-296-00 1-216-296-00 1-216-296-00 1-216-295-00 1-216-295-00 1-216-295-00 1-216-295-00 SHORT SHORT SHORT SHORT SHORT SHORT SHORT SHORT SHORT 0
Ref. No. R348 R349 R350 Part No. Description 6.8K 10 1.5K 5% 5% 5% Remark 1/10W 1/10W 1/10W Ref. No. Part No. Description 1-216-069-00 METAL CHIP 1-216-001-00 METAL CHIP 1-216-053-00 METAL CHIP
< VARIABLE RESISTOR > RV301 1-223-968-11 RES, VAR, CARBON 20K/20K (VOL) RV302 1-225-641-11 RES, VAR, CARBON 10K (TUNING) RV303 1-238-857-11 RES, ADJ, CERMET 22K ************************************************************ * 1-670-527-11 SW BOARD ********* < SWITCH > SW1 1-572-467-61 SWITCH, PUSH (1 KEY) (POWER) ************************************************************ MISCELLANEOUS ************** MDD01 1-505-117-21 DRIVER (L-CH) MDD02 1-505-117-21 DRIVER (R-CH)

Sony Corporation

9-924-925-11
Personal A&V Products Company
98F057022-1 Printed in Singapore 1998. 6 Published by Quarity Engineering Dept. (Shibaura)