Sony MDR-RF415R Service manual

MDR-RF415R

SERVICE MANUAL

Ver 1.0 2001. 02

MDR-RF415R is the component model block one in the MDR-RF415RK.

COMPONENT MODEL NAME FOR MDR-RF415RK

Headphones MDR-RF415R Transmitter TMR-RF415R

AEP Model

SPECIFICATIONS

Power source DC 2.4 V: Built-in rechargeable battery Mass Approx. 240 g (8.5 oz.) incl.

built-in rechargeable battery

Built-in Ni-Cd rechargeable battery

Model name NC-AA V oltage 1.2 V Capacity 700 mAh

Design and specifications are subject to change without notice.

HEADPHONES

9-873-075-11

Sony Corporation

Audio Entertainment Group General Engineering Dept.

MDR-RF415R

SECTION 1

GENERAL

This section is extracted from instruction manual.

Turn up the volume to a moderate level with the VOL control, then tune the headphones in to the frequency of the transmitter with the TUNING control until you can hear the audio signal loud and clear.

TUNING control

VOL control

Auto power on/off function

When you remove the headphones from your head, the power turns off automatically. Do not allow the self adjusting band to be pulled up, otherwise the headphones will be switched on.

The power turns on.

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.

SECTION 2

DISASSEMBLY

Note : Follow the disassembly procedure in the numerical order given.

2-1. RX-BASE BOARD

Five screws (P 2

MDR-RF415R

× 6)

Cover (R), hanger

Claw

Precaution for installtion

Slide the suspender in the

direction of the arrow.

Suspender

Set the push

switch (1 key).

Switch, push (1 key)

Remove the two solderings.

Claw

RX-BASE board

Screw (P 2

Remove the

nine solderings.

× 8)

Precaution for installtion

No.205

RX-BASE board

No.204

No.201

No.201 (green)

No.202

No.203

No.203 (black)

Solder the each lead wires directly to the position as shown while being cautions of colors.

No.204

No.202 (red)

MDR-RF415R

Set the lead wires

Set the each lead wires as illustrated below.

Cover (L), hanger

Groove

No.203

No.201

To the driver (030F032//K).

Groove

No.205

No.201, No.203

Groove

No.202

Groove

To the RX-BASE board

Cover (R), hanger

No.204

To the driver (030F032//K).

No.203

No.201

No.202

No.201, No.203

Cover (L), hanger

Groove

Cover (R), hanger

SECTION 3

ELECTRICAL ADJUSTMENTS

MDR-RF415R

Notes:

1. Use transmitter with check and adjustment already completed.

2. On adjusting the headphones section, use the transmitter as a jig.

Headphones:MDR-RF415R Transmitter:TMR-RF415R

Procedure:

1. Connect an oscillator with attenuator and terminator (600 Ω) to the transmitter AUDIO IN-A connector (J402).

2. Connect an A C adapter to the transmitter DC IN 9V jack (J404).

3. Connect lead wires to IC301 pin 4, pin 6, pin 7 and GND on the RX-BASE board.

4. Connect a resistor 33k Ω between IC301 pin 4 and pin 7.

5. Connect lead wires to the speakers’ terminals (L+,L-,R+,R-) on the RX-BASE board.

3-1. Free run frequency check and adjustment

1. Set the transmitter A UDIO IN-A connector (J402) to no signal.

Note: In this case, operation time is about 4 or 5 minutes.

2. Check the transmitter power indicator (red) lights.

3. Set the transmitter CHANNEL switch to 1.

4. Set the headphones tuning (RV303) to center position.

5. Connect a frequency counter to IC301 pin 4 and GND on the RX-BASE board.

6. Adjust the value of the frequency counter to specification by RV301 on the RX-BASE board.

Specified Values: 76kHz ± 50Hz.

3-2. Receive frequency check and adjustment

1. Set the transmitter CHANNEL switch to 2.

2. Set the transmitter NOISE FILTER switch to OFF.

3. Input a signal of 1kHz, 316mVrms to transmitter AUDIO IN-A-L connector only.

4. Keep distance transmitter and headphones to 5 meters over.

5. Set the headphones volume (RV302) to minimum.

6. Set the headphones tuning (RV303) to center position. Connect an oscilloscope CH1 and CH2 to IC301 pin 6 and pin 4.

8. Check the waveform of the oscilloscope to CH1 is demodulated 1kHz signal and CH2 is GND.

9. If CH1 and CH2 are not satisfied step 8, adjust the coil (L301) on the RX-BASE board to satisfied step 8.

10. Set the transmitter CHANNEL switch to 1 or 3.

11. Adjust the headphones tuning (RV303) to receive radio frequency.

12. Check same step 8.

3-3. Carrier modulation check

1. Set the transmitter CHANNEL switch to 2.

2. Set the transmitter NOISE FILTER switch to OFF.

3. Input a signal of 1kHz, 316mVrms to transmitter AUDIO IN-A-L connector only.

4. Adjust the headphones tuning (RV303) to receive radio freqency.

5. Set the headphones volume (RV302) to minimum.

Connect an oscilloscope CH1 and CH2 to IC301 pin 6 and pin 4.

7. Check the waveform of the oscilloscope to CH1 is demodulated 1kHz signal and CH2 is GND.

8. Connect an AC volt meter to IC301 pin 6 and GND.

9. Check the value of the AC volt meter to 26mVrms ± 2mV

3-4. Separation check

1. Set the transmitter CHANNEL switch to 2.

2. Set the transmitter NOISE FILTER switch to OFF.

3. Input a signal of 1kHz, 316mVrms to transmitter AUDIO IN-A-L connector only.

4. Adjust the headphones tuning (RV303) to receive radio freqency.

5. Connect an oscilloscope to CH1 is demodulated 1kHz signal and CH2 is GND.

6. Check the waveform of the oscilloscope to CH1 is demodulated 1kHz signal and CH2 is GND.

Connect an A C v olt meter with LPF to speakers terminal (L+,L-).

8. Adjust the value of the AC volt meter to specification by headphones volume (RV302).

Specified V alue: 155mVrms

Connect an A C volt meter with LPF to speak ers terminal (R+,R-).

10. Measure the value of the AC volt meter.

11. Check the difference of the L and R to more than 20dB.

12. Input a signal of 1kHz, 316mVrms to transmitter AUDIO IN-A-R connector only.

13. Connect an AC volt meter to speakers terminal (R+,R-).

14. Adjust the value of the AC volt meter to specification by headphones volume (RV302).

Specified V alue: 155mVrms

15. Connect an AC volt meter to speakers terminal (L+,L-).

16. Measure the value of the AC volt meter.

17. Check the difference of the L and R to more than 20dB.

Adjustment Location : (See page 6)

MDR-RF415R

Adjustment Location :

[RX-BASE BOARD]

(Conductor side)

IC301

GND

RV303

R323

C334

JC324

power

L–

L+

R–

R+

SECTION 4

DIAGRAMS

MDR-RF415R

4-1. BLOCK DIAGRAM

FRONT END

FE UNIT

D301

RECEIVE

L301

FREQ.

FM FE

RV303

TUNE

L302

CF301

10.7MHz

CF302

10.7MHz

REG

• IC BLOCK DIAGRAM

IC302 LA4533M

IF AMP/DECODE

IC301

FM IF/

1316

DISCRI

MUTE

PD1

1/2

COUNTER

VCO

RV301

FREE RUN

FREQ.

AUTO

BLEND

DECODE

AMP

MONO/ST

STEREO

IND

6 2 9

R-CH

RV302

VOLw

B+

power

AUDIO AMP

IC302

D304

ON/OFF SW

Ni-Cd

1.2 x 2

R-CH

R-ch is omitted.

• Signal path. F: FM

SPEAKER

L-CH

SPEAKER

R-CH

P/SW

IN1

PRE GND

IN2

REF

AMP1

AMP2

MUTE

CIRCIUT

MT/SW

OUT1

POWER GND

OUT2

VCC

POWER

SWITCH

BIAS

+ 15 hidden pages