Sony MDR-RF975R User manual

MDR-RF975R
SERVICE MANUAL
HEADPHONES
SPECIFICATIONS
US Model
MDR-RF975R is the component model block one in the MDR-RF975RK.
9-873-141-12
2001F0200-1
© 2001.6
Sony Corporation
Personal Audio Company
Shinagawa Tec Service Manual Production Group
Ver 1.1 2001. 06
Headphones MDR-RF975R
Transmitter TMR-RF975R
COMPONENT MODEL NAME FOR MDR-RF975RK
Headphones
Power source DC 2.4 V: Built-in rechargeable
battery
Mass Approx. 350 g (12.3 oz.) incl.
built-in rechargeable battery
Built-in Ni-MH rechargeable battery
Model name NH-AAC
Voltage 1.2 V
Capacity 1,000 mAh
Design and specifications are subject to change without
notice.

2
MDR-RF975R
This section is extracted from
instruction manual.
Flexible Circuit Board Repairing
• Keep the temperature of soldering iron around 270°C
during 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
damaged by heat.
SECTION 1
GENERAL
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.
5Turn up the volume to a moderate level
with the VOL control.
Press the TUNING button briefly for
automatic tuning of the headphones.
If you do not receive a clear audio signal,
press it again.
Try the above steps 3 and 5 until the
receiving performance becomes better.
TUNING
button
VOL control
TABLE OF CONTENTS
Specifications ............................................................................ 1
1. GENERAL ......................................................................... 2
2. DISASSEMBLY
2-1. Driver (R Side), RX-BASE Board ........................... 3
2-2. SW Board, Hanger (R) ............................................. 4
2-3. Holder (R) ................................................................. 4
2-4. Driver (L Side) .......................................................... 5
2-5. Hanger (L) ................................................................ 6
2-6. Holder (L) ................................................................. 6
3. ELECTRICAL ADJUSTMENTS
3-1. Free Run Frequency Check and Adjustments ........... 7
3-2. Receive Frequency Check and Adjustments ............ 7
3-3. Carrier Modulation Check ........................................ 7
3-4. Expander Output Check ............................................ 7
3-5. Separation Check ...................................................... 7
4. DIAGRAMS
4-1. Block Diagrams ....................................................... 11
4-2. Schematic Diagram ................................................. 12
4-3. Printed Wiring Board .............................................. 13
5. XPLODEDVIEWS....................................................... 14
6. ELECTRICAL PARTSLIST..................................... 15

3
MDR-RF975R
SECTION 2
DISASSEMBLY
2-1. DRIVER (R SIDE), RX-BASE BOARD
•The equipment can be removed using the following procedure .
Driver (R side), RX-BASE board
Driver (L side), Hanger (L)
Set SW board, Harger (R)
Holder (L)
Holder (R)
Note: Follow the disassembly procedure in the numerical order given .
Four
claws
RX-BASE board
SW board
SW board
(Housing (R) side)
Housing (R)
Solder the each leads directly to the position as shown
while being cautions of colors.
Set the each leads as illustrated below.
Precaution for installtion
Precaution for installtion
Precaution for installtion
Head band
assy (front)(natural)
Head band
assy (front)(red)
Head band
assy (rear)(green)
Head band
assy (rear)(natural)
Driver (red)
Driver (natural)
Red Natural
From RX-BASE board.
From head
band assy (front).
From head
band assy (rear).
From
SW board.
Driver (R side)
ANT
qa RX-BASE board
0 Remove the
eight solderings.
2 Four screws (M 2 × 5)
1 pad, ear
4 Holder (R),ear pad
3 Plate (R) assy, front
6 Driver
8 Charge terminal
9 Volume knob
5 Remove the
two solderings.
7 Remove the
two solderings.
Groove
Groove

4
MDR-RF975R
2-3. HOLDER (R)
2 Housing (R)
5 Holder (R)
3 Holder (R)
8 SW board
SW board
3 Lid (R), hanger
9 Hanger (R)
Hanger (R)
1
1
Precaution for installtion
Set the each leads as illustrated below.
7 Remove the
two solderings.
4 Two screw
s
(P 2 × 8)
1 Screw (P 2 × 8)
2 Spring
(ON/OFF)
4 Cushion assy, head
6 Chassis
5 Two screws
(P 2
× 8)
7 Band assy (rear), head
8 Band assy (front), Head
From head
band assy (front).
From head
band assy (rear).
From
SW board.
Groove
Groove Groove
Groove
Groove
Groove
6
2-2. SW BOARD, HANGER (R)

5
MDR-RF975R
2-4. DRIVER (L SIDE)
Housing (L)
Set the each leads as illustrated below.
Precaution for installtion
Precaution for installtion
Green Natural
Green
Natural
From head band assy (rear).
From head
band assy (front).
From head
band assy (rear).
Driver (L side)
2 Four screws (M 2 × 5)
1 Pad, ear
6 Ear pad
holder (L)
3 Plate (L) assy, front
8 Driver
Four
claws
7 Remove the
two solderings.
4 Two "batterys,
nickle hydrogen"
5 Remove the
two solderings.
Groove
Groove

6
MDR-RF975R
2-5. HANGER (L)
2-6. HOLDER (L)
2 Housing (L)
5 Holder (L)
2 Holder (L)
3 Lid (L), hanger
7 Hanger (L)
Hanger (L)
1
1
Precaution for installtion
Set the each leads as illustrated below.
4 Two screws
(M 2
× 5)
1 Screw (M 2 × 5)
3 Cushion assy, head
5 Chassi
s
4 Two screws
(M 1.7
× 3)
7 Band assy
(rear), head
6 Band assy (front),head
From head
band assy (front).
From head
band assy (rear).
Groove
Groove
Groove
6

7
MDR-RF975R
SECTION 3
ELECTRICAL ADJUSTMENTS
Notes:
1. Use transmitter with check and adjustment alreadycompleted.
2. On adjusting the headphones section, use the transmitter as a
jig.
Headphones:MDR-RF975R
Transmitter:TMR-RF975R
Procedure:
1. Connect an oscillator with attenuator and terminator (600 Ω)
to the transmitter AUDIO IN-A connector (J402).
2. Connect an AC adapter to the transmitter DC IN 9V jack (J404).
3. Short between Q303 collector and GND on the RX board.
4. Connect DC 2.4V to the +B power line externally.
5. Connect lead wires to IC301 pin 4, pin 6, pin 7, IC 307 pin 7,
IC 308 pin 7 and GND on the RX-BASE board.
6. Connect a 33kΩresistor between IC301 pin 4 and pin 7.
7. Connect lead wires to the speakers’ terminals (L+,L-,R+,R-)
on the RX-BASE board. (See page 9)
3-1. Free Run Frequency Check and Adjustment
1. Set the transmitter AUDIO IN-A connector (J402) to no signal.
Note: In this case, operation time is about 5 or 10 minutes.
Perform the confirmation for less than 5 minutes.
2. Check the transmitter power indicator (red) lights.
3. Set the transmitter CHANNEL switch to 1.
4. Connect DC 1.2V across TP and GND.
5. Connect a frequency counter to IC301 pin 4 and GND on the
RX-BASE board, then confirm the frequency within 76KHz
±50Hz.
6. When the frequency dose not satisfy the specified value, adjust
the value of the frequency counter to specification by RV301
on the RX-BASE board.
Specified values: 76kHz ±50Hz.
7. Remove a 33kΩ resistor between IC301 pin 4 and pin 7.
Setting :
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-ch) connector only.
4. Keep distance between transmitter and headphones to 5 meters
over.
5. Set the headphones volume (RV302) to minimum.
6. Connect DC 1.2V across TP and GND.
7. 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 in step 8, adjust the coil (L301)
on the RX board to satisfied step 8.
10. Open between Q303 corrector and GND on the RX board.
11. When the transmitter off, check the waveform of the
oscilloscope as follows:
12. Set the transmitter CHANNEL switch to 1.
13. Push the headphones tuning switch (S301) to receive radio
frequency.
14. Check same step 8.
15. Set the transmitter CHANNEL switch to 3.
16. Push the headphones tuning switch (S301) to receive radio
frequency.
17. 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-ch) connector only.
4. Set the headphones volume (RV302) to minimum.
5. Connect an oscilloscope CH1 and CH2 to IC301 pin 6 and
pin 4.
6. Push the headphones tuning switch (S301) to receive radio
frequency.
7. Check the waveform of the oscilloscope that the CH1 is
demodulated 1kHz signal and CH2 is GND.
8. Connect an AC voltmeter with LPF to IC301 pin 6 and GND.
9. Check the value of the AC voltmeter to 40mVrms ±5mV
Setting :
3-5. 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-ch) connector only.
4. Connect an oscilloscope CH1 to speakers terminal (L+,L-) and
CH2 to IC301 pin 4 and GND.
5. Push the headphones tuning switch (S301) receive radio
frequency.
+
–
Regulated power supply
(DC 1.2V)
Frequency counter
TP
+
–
IC301 pin
4
GND
1.8V
2-3sec 0.6V
Setting :
+
–
Regulated power supply
(DC 1.2V)
TP
+
–
+
–
IC301 pin6 IC301 pin
4
OSCILLOSCPE
CH1 CH2
+
–
Digital voltmeter
(AC range)
LPF
IC301
pin6
33000P
2.2K
+
–
+
–
IC301 pin6 IC301 pin4
OSCILLOSCPE
CH1 CH2
3-4. Expander Output Check
1. Set the transmitter CHANNEL switch to 2.
2. Input a signal of 1kHz, 316mVrms to transmitter AUDIO IN-A
L and R connector.
3. Connect an AC voltmeter to IC307 pin 7 and IC308 pin 7.
4. Measure the value of the AC voltmeter.
5. Input a signal of 1kHz, 31.6mVrms to transmitter AUDIO IN-
A L and R connector.
6. Measure the value of the AC voltmeter.
7. Check the difference of the step 4 and step 6 to more than 20
dB ±3 dB.
Setting :
+
–
Digital voltmeter
(AC range)
IC307 pin
7
IC308 pin
7
Ver 1.1 2001.06

8
MDR-RF975R
13. Connect an AC voltmeter with LPF to speakers terminal
(R+,R-).
14. Adjust the value of the AC voltmeter to specification by
headphones volume RV302.
Specified values: 155mVrms
15. Connect an AC voltmeter with LPF to speakers terminal
(L+,L-).
16. Measure the value of the AC voltmeter.
17. Check the difference of the L and R to more than 25dB.
Setting :
+
–
Digital voltmeter
(AC range)
L+ / R+
L–/ R–
+
–
+
–
L+ IC301 pin
4
OSCILLOSCPE
L–
CH1 CH2
LPF
33000P
2.2K
6. Check the waveform of the oscilloscope that the CH1 is
demodulated 1kHz signal and CH2 is GND.
7. Connect an AC voltmeter with LPF to speakers terminal
(L+L-).
8. Adjust the value of the AC voltmeter to specification by
headphones volume RV302.
Specified values: 155mVrms
9. Connect an AC voltmeter with LPF to speakersterminal
(R+,R-).
10. Measure the value of the AC voltmeter.
11. Check the difference of the L and R to more than 25dB.
12. Input a signal of 1kHz, 316mVrms to transmitter AUDIO IN-A
(R-ch) connector only.
Ver 1.1 2001.06

9
MDR-RF975R
RX-BASE BOARD
(Conductor side)
R304
L302
IC301
C315
R302
C302
R310
C313
R312
C317
C332
C319
R308
C301
R305
C331 C329
C340
R340
R341
R342
R343
C341
R349
R344
R345
R346
R347
R348 C343
C342
IC302
C346
C345
R360
C344
R354
Q304
R362
R355
R358
R366
R356
R318
C323
R364
R321
R309
C333
R367
R357 R350
R351
R352
R353
IC305
D303
R320
R330
IC303
Q303
R322
IC304
C320
C336
R316
C328
R315
C327
D301
C307
R333
R334
R325
Q301
C361
C362
C363
D304
power
R314
R361
Q305
R363
R331
C352
C355
D310
C359
C318
C337
R332
JC303
JC304
JC306
JC309
JC311
C305
C304
C357
C314
C321
C322
JC331
JC332
JC333
JC334
C326
C325
C324
C347
JC335
JC336
C312
C316
C393
C394
L301
RV301
CF301
C330
C310
CF302
C311
C381
C380
C303
C308
C306
C309
S301
15
10 6
IC301 7
IC301 4
IC301 6
GND
Short
L–
L+
R–
R+
GND
TP
L301:
Receive frequency
Adjustment
RV302: Volume control
+B
power line
(DC 2.4V)
RV301:
Free Run Frequency
Adjustment
(Connect a 33 K Ω resistor
)
Asjustment Location :

10
MDR-RF975R SECTION 4
DIAGRAMS
Note on schematic diagrams.
Note:
• All capacitors are in µF unless otherwise noted. pF: µµF 50 WV or
less are not indicated except for electrolytics and tantalums.
• All resistors are in Ωand 1/4W or less unless otherwise specified.
•f: internal component.
•A: B+ Line.
•H: adjustment for repair.
• Power voltage is dc 2.4V and fed with regulated dc power supply
from battery terminal.
• Voltages are dc with respect to ground under no-signal conditions.
• Voltages are taken with a VOM (Input impedance 10 MΩ).
• Signal path.
F: FM
L: AUDIO
• IC BLOCK DIAGRAMS
IC302 LA4533M TP-1
IC305 TC7W74FU (TE12R)
POWER
SWITCH
MUTE
CIRCIUT
BIAS
1
2
3
4
56
7
8
9
10 MT/SW
OUT1
POWER GND
OUT2
VCC
P/SW
IN1
PRE GND
IN2
REF
AMP2
AMP1
6
CLR
7
PR
8
VCC
5
Q
RSQ
3
Q
2
D
4
GND
1
CK
QDC

MDR-RF975R
11
11
4-1. BLOCK DIAGRAMS
L301
RECEIVE
FREQ.
D301
+V +V
FRONT END
FE UNIT 18 1316 FM IF/
DISCRI
DECODE
AMP
DETUNE
MUTE
TUNING
IND
STEREO
IND
CF301
26
CF302
10.7MHz
6 2
10
9
5R-CH
R-CH
SPEAKER
L-CH
SPEAKER
R-CH
POWER AMP
IC302
MUTE
Q304
22
20
FM FE
L302
+V
COUNTER
IC303
DETECT
IC304
HPF
Q306
(L-CH)
(R-CH)
LPF EQ
IC309 IC306
EXPANDER
AMP
IC308
IC307
FF
IC305
OSC
Q301
SWITCH
Q303
10
12
27
S301
TUNE
Q305
DQ
Q
AUTO
BLEND
MUTE MONO/ST
SW
1/2
COUNTER
PD1
PD1
VCO
21
REG
RV301
FREE RUN
FREQ.
IF AMP/DECODE
IC301
D304
S1
ON/OFF SW
+
–
B+
• Signal path.
• R-ch is omitted due to same as L-ch.
: FM
: AUDIO
power
RX-BASE BOARD
ANT301
RX-SW BOARD
CHARGE
TERMINAL
(TO TMR-RF975R)
RECHAGEABLE BATTERY
(NICKEL-CADMIUM)
NH-AAC
2PCS, 2.4V
RV302
VOL
w

MDR-RF975R
12
12
4-2. SCHEMATIC DIAGRAM • See page 10 for Notes. • See page 10 for IC Block Diagrams.
R332
C306
C309 C310
C311
C312
C316
C324
C325
C326
CF301
CF302
JC303
JC304
JC306
JC309
JC311
L301
L302
0.33µH
R302
R304 R305
R308
R309
R310
R312
R314
R315
R316
R318
R320
R321
R322
R325
R330
R331
R333
R334
R341 R342 R343
R344
R345
R346
R347
R348
R350 R351 R352 R353
R354
R355
R356
R357
R358
R361
R362
R363
R364
R366
R367
RV301
RV302(2/2)
C308
C347
R360
C303
Q304
Q305
IC305
IC304
IC303
Q303
R386
R395 R397
R399
R398
R391
R390
R384
R382
R387
R385
R383
R380
R376
R377
R370 R371
R374
R372 R373
R375
R393
R392
R378
R379
C400
R401
R404
R403
R400
C381
C380
C393
C394
IC301
D301
Q301
R349
C330
RV302(1/2)
IC302
D304
D310
IC306
IC309
Q306
Q307
IC308
IC307
S302
R340
C340
JC331
JC332
JC333
JC334
JC335
JC336
JC350
C359
C313
C314
C320
C333
C317 C355 C352
C336
C332 C319
C302
C301
C304
C305 C307
C378
C331
C371
C370
C353
C379
C382
C386
C384 C388
C354
C372 C373
C383
C387
C385
R381 C389 C404
C377
C376
C392
C356
C375
C374
C391
C341
C329 C337
C342
C343
C345
C344
C321
C318
C322
C362
C361
C323
C357
C327
C328 C363
ANT301
C315
S301
C397
C395 C402
R394 R396
C403
C396
C398
C399
C346
D303
1.0k
22
16V
1
50V 1
50V
10
16V
3.3
50V
10
16V
220
6.3V
220
6.3V
220
6.3V
10.7MHz
10.7MHz
DISC
0
0
0
0
0
AIR COIL
2.2k
3.3k 3.3k
2.2k
100k
3.3k
15k
100k
10
10
47k
10
1.5k
6.8k
330
10
2.2k
2.2k
2.2k
470k 240k 120k
62k
30k
15k
7.5k
47k
15k 1M 1M 15k
22k
47k
22k
22k
22k
22k
10k
22k
22k
150
47k
4.7k
22
16V
47 16V
22k
4.7/16V
2SC2712L
DTC114TK
TC7W74FU
BA10393F
TC74HC4024
2SC2712L
4.7k
3.3k 27k
10k
10k
100k
100k
5.6k
2.2k
4.7k
5.6k
2.2k
1.0k
100k
100k
8.2k 8.2k
4.3k
8.2k 8.2k
4.3k
2.2k
3.9k
3.9k
2.2k
0.1
F
100
10k
10k
100
4.7
16V
4.7
16V
10
16V
10
16V
CXA1538N
1T363
FMW1
10k
33
25V
LA4533M
TLSU124
RB411D
NJM2100E
NJM2100E
2SC2712L
2SC2712L
TK10691M
TK10691M
8.2k
0.1
0
0
0
0
0
0
0
0.001
0.01
68p
0.1
3p
0.001 0.001 0.001
56p
56p 0.01
0.47
1
0.001
0.001 0.01
2200p
1
1000p
1000p
0.01
2200p
1
0.022
2200p 150pF
0.01
1000p 1000p
1
0.022
2200p
1k 150pF 1
2.2
220p
2.2
1000p
2.2
220p
2.2
0.1
0.01 100p
0.01
0.01
0.1
0.1
1
0.01
1
100p
100p
0.1
0.01
0.1
0.1 0.01
ANTENNA
10p
2.2
10.022
3.3k 27k
0.022
1
2.2
0.01
0.22
UDZ-TE-17-2.2B
SPEAKER
SPEAKER
TO
(R-ch)
(L-ch)
RECHARGEABLE
BATTERY
2pcs,2.4V
FE UNIT
(FRONT END)
FF
OSC
OSC SWITCH
BUFFER
AUDIO MUTE
FREE
RUN
FREQ.
LPF
RV302
IF AMP/DECODE
TUNE
DETECT
HPT
EQ AMP
EXPANDER
AMP
EXPANDER
AMP
POWER AMP
GND
CAP
RECT
20K
RECTIFIER
CAP
20K
REF
REFERENCE
IN
CONT
GAIN CELL
60K
SUN IN
NFIN VCC
1
2
3
45
6
7
8
SUM
GND
CAP
RECT
20K
RECTIFIER
CAP
20K
REF
REFERENCE IN
CONT
GAIN CELL
60K
SUN IN
NFIN VCC
1
2
3
45
6
7
8
SUM
+
-
+
-
power
TMR-RF975R
HPF
NH-AAC
COUNTER
(POWER ON/OFF)
(NICKEL-CADMIUM)
CHARGE
(BATTERY
TERMINAL)
+
-
REF
OUT1
POWER
OUT2
VCC
P S/W
IN1
IN2
MT/SW
GND
PRE
GND

MDR-RF975R
13
13
Ref. No. Location
D301 C-2
D303 D-5
D304 D-3
D310 E-3
IC301 B-3
IC302 E-4
IC303 C-2
IC304 D-4
IC305 D-4
IC306 E-8
IC307 D-8
IC308 D-8
IC309 D-8
Q301 C-4
Q303 C-4
Q304 D-3
Q305 C-3
Q306 C-8
Q307 C-7
• Semiconductor
Location
Note:
•X: parts extracted from the component side.
•a: Through hole.
•: Pattern from the side which enables seeing.
(The other layer's patterns are not indicated.)
4-3. PRINTED WIRING BOARD
Caution:
Pattern face side: Parts on the pattern face side seen from the
(Side B) pattern face are indicated.
Parts face side: Parts on the parts face side seen from the
(Side A) parts face are indicated.
11
(11)
1-677-934-
11
(11)
1-678-658-
RX-BASE BOARD (SIDE A)
23 4 5 6 7 89 10
A
1
B
C
D
E
F
ANT301
(ANTENNA)
S302
(POWER ON/OFF)
RX-SW BOARD
FE UNIT
(FRONT-END)
R304
L302
IC301
C315
R302
C302
R310
C313
R312
C317
C332
C319
R308
C301
R305
C331 C329
C340
R340
R341
R342
R343
C341
R349
R344
R345
R346
R347
R348 C343
C342
IC302
C346
C345
R360
C344
R354
Q304
R362
R355
R358
R366
R356
R318
C323
R364
R321
R309
C333
R367
R357 R350
R351
R352
R353
IC305
D303
R320
R330
IC303
Q303
R322
IC304
C320
C336
R316
C328
R315
C327
D301
C307
R333
R334
R325
Q301
C361
C362
C363
D304
power
R314
R361
Q305
R363
R331
C352
C355
D310
C359
C318
C337
R332
JC303
JC304
JC306
JC309
JC311
C305
C304
C357
C314
C321
C322
JC331
JC332
JC333
JC334
C326
C325
C324
C347
JC335
JC336
C312
C316
C393
C394
L301
RV301
CF301
C330
C310
CF302
C311
C381
C380
C303
C308
C306
C309
S301
C396
C403
C395
C392
C391
R396
R370
R395
R397
C399
C370
R374
C371
R371
C378
R376
R380
C379
C373
C372
R375
R381
C383
R377
C400
R391
R384
R386
R373
C382
R382
C374
R378
C375
R379
C376
R392
R393
C377
R399
C389
R390
C387
R387
C385
R385
R383
C397
R394
C402
R398
C398
IC309
IC306
IC307
IC308
R372
C386
C388
C384
C404
R404
R403
C356
R400
R401
C353
C354
Q307
Q306
JC350
11
(11)
1-677-934-
RX-BASE BOARD (SIDE B)
S301
TUNE
RV302
VOL
w
RECHAGEABLE BATTERY
(NICKEL-CADMIUM)
NH-AAC
2PCS, 2.4V
+
–
TO TMR-RF975R
(BATTERY CHARGE TERMINAL)
15
10 6
SPEAKER
(R-CH)
–
+
SPEAKER
(L-CH)
–
+

14
MDR-RF975R
Ref. No. Part No. Description Remarks Ref. No. Part No. Description Remarks
SECTION 5
EXPLODED VIEWS
NOTE:
• -XX, -X mean standardized parts, so they may
have some differences from the original one.
• 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.
• Hardware (# mark) list and accessories and
packing materials are given in the last of this
parts list.
3
36
4
14
15
#1
#1
#2
#1
#1
#2
#2
#2
#2
#2
d
b
a
c
d
c
b
e
e
a
14
20
6
5
37
24
25
34
32
28
2
35
31
7
6
10
4
33
12
13
21
22
26
37
37
37
37
1
37 17
9
18
19
16
8
23
29
not
supplied
not
supplied
not
supplied
not
supplied
not supplied
not
supplied
not
supplied
not
supplied
1 3-224-689-01 SHEET (R), LIGHT PREVENTION
2 3-846-312-01 SPACER
3 X-3379-301-1 CUSHION ASSY, HEAD
4 3-046-718-01 PAD, EAR
5 X-3379-304-1 PLATE (L) ASSY, FRONT
6 X-3380-120-1 DRIVER ASSY
7 3-046-723-01 HOLDER (L), EAR PAD
8 1-756-109-11 BATTERY, NICKEL HYDROGEN
9 3-046-717-01 TERMINAL (SMALL), BATTERY
10 X-3380-844-1 HOUSING (L) ASSY
11 3-046-709-11 CAP (L), ORNAMENTAL
12 3-046-716-01 TERMINAL (LARGE), BATTERY
13 3-046-696-01 HOLDER (L)
14 3-046-695-01 CHASSIS
15 3-046-698-01 LID (L), HOLDER
16 3-220-123-01 PLATE (L), HOUSING ORNAMENTAL
17 3-046-707-01 HOUSING (L)
18 3-049-953-21 LID (L), HANGER
19 3-046-705-01 HANGER (L)
20 3-046-699-01 LID (R), HOLDER
*21 1-678-658-11 RX-SW BOARD
22 3-046-697-02 HOLDER (R)
23 3-046-706-01 HANGER (R)
24 3-049-954-21 LID (R), HANGER
25 3-046-708-01 HOUSING (R)
26 X-3380-845-1 HOUSING (R) ASSY
*28 A-3062-570-A RX-BASE BOARD, COMPLETE
29 3-049-797-01 LIGHT, MDR GUIDE
31 3-220-124-01 PLATE (R), HOUSING ORNAMENTAL
32 3-046-715-01 TERMINAL, CHARGE
33 3-049-951-01 KNOB, VOLUME
34 3-046-724-01 HOLDER (R), EAR PAD
35 X-3380-341-1 PLATE (R) ASSY, FRONT
36 3-224-569-01 SPRING (ON/OFF)
37 3-223-909-01 SCREW (B2)
38 3-224-572-01 SHEET, HOLOGRAM (L) ADHESIVE
39 3-224-688-01 SHEET (L), LIGHT PREVENTION
#1 7-627-553-28 SCREW,PRECISION +P 2X2.5
#2 7-685-104-14 SCREW +P 2X6 TYPE2 NON-SLIT

15
Ref. No. Part No. Description Remarks Ref. No. Part No. Description Remarks
MDR-RF975R
SECTION 6
ELECTRICAL PARTS LIST
Ref. No. Part No. Description Remarks Ref. No. Part No. Description Remarks
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, -X mean standardized parts, so they
may have some difference from the original
one.
• 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: µ, for example:
uA...: µA... , uPA... , µPA... ,
uPB... , µPB... , uPC... , µPC... ,
uPD..., µPD...
When indicating parts by reference number,
please include the board name.
RX-BASE
• CAPACITORS:
uF: µF
• RESISTORS
All resistors are in ohms.
METAL: metal-film resistor
METAL OXIDE: Metal Oxide-film resistor
F: nonflammable
• COILS
uH: µH
*A-3062-570-A RX-BASE BOARD, COMPLETE
*********************
3-046-715-01 TERMINAL, CHARGE
3-049-951-01 KNOB, VOLUME
< CAPACITOR >
C301 1-164-346-11 CERAMIC CHIP 1uF 16V
C302 1-164-005-11 CERAMIC CHIP 0.47uF 25V
C303 1-124-259-11 ELECT 4.7uF 20% 16V
C304 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C305 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C306 1-124-234-00 ELECT 22uF 20% 16V
C307 1-163-059-91 CERAMIC CHIP 0.01uF 10% 50V
C308 1-124-234-00 ELECT 22uF 20% 16V
C309 1-104-942-11 ELECT 1uF 20% 50V
C310 1-104-942-11 ELECT 1uF 20% 50V
C311 1-124-233-11 ELECT 10uF 20% 16V
C312 1-126-162-11 ELECT 3.3uF 20% 50V
C313 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C314 1-164-441-11 CERAMIC CHIP 68PF 5% 50V
C315 1-163-227-11 CERAMIC CHIP 10PF 0.50PF 50V
C316 1-124-233-11 ELECT 10uF 20% 16V
C317 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C318 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C319 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C320 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C321 1-164-346-11 CERAMIC CHIP 1uF 16V
C322 1-164-346-11 CERAMIC CHIP 1uF 16V
C323 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C324 1-124-635-00 ELECT 220uF 20% 6.3V
C325 1-124-635-00 ELECT 220uF 20% 6.3V
C326 1-124-635-00 ELECT 220uF 20% 6.3V
C327 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C328 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C329 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C330 1-124-242-00 ELECT 33uF 20% 25V
C331 1-164-346-11 CERAMIC CHIP 1uF 16V
C332 1-163-245-11 CERAMIC CHIP 56PF 5% 50V
C333 1-163-220-11 CERAMIC CHIP 3PF 0.25PF 50V
C336 1-163-245-11 CERAMIC CHIP 56PF 5% 50V
C337 1-163-251-11 CERAMIC CHIP 100PF 5% 50V
C340 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C341 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C342 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C343 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C344 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C345 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C346 1-164-489-11 CERAMIC CHIP 0.22uF 10% 16V
C347 1-124-589-11 ELECT 47uF 20% 16V
C352 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C353 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C354 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C355 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C356 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C357 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C359 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C361 1-163-251-11 CERAMIC CHIP 100PF 5% 50V
C362 1-163-251-11 CERAMIC CHIP 100PF 5% 50V
C363 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C370 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C371 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C372 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C373 1-163-009-11 CERAMIC CHIP 0.001uF 10% 50V
C374 1-163-259-91 CERAMIC CHIP 220PF 5% 50V
C375 1-164-505-11 CERAMIC CHIP 2.2uF 16V
C376 1-163-259-91 CERAMIC CHIP 220PF 5% 50V
C377 1-164-505-11 CERAMIC CHIP 2.2uF 16V
C378 1-164-161-11 CERAMIC CHIP 0.0022uF 10% 100V
C379 1-164-161-11 CERAMIC CHIP 0.0022uF 10% 100V
C380 1-124-259-11 ELECT 4.7uF 20% 16V
C381 1-124-259-11 ELECT 4.7uF 20% 16V
C382 1-164-346-11 CERAMIC CHIP 1uF 16V
C383 1-164-346-11 CERAMIC CHIP 1uF 16V
C384 1-164-161-11 CERAMIC CHIP 0.0022uF 10% 100V
C385 1-164-161-11 CERAMIC CHIP 0.0022uF 10% 100V
C386 1-163-037-11 CERAMIC CHIP 0.022uF 10% 25V
C387 1-163-037-11 CERAMIC CHIP 0.022uF 10% 25V
C388 1-163-255-11 CERAMIC CHIP 150PF 5% 50V
C389 1-163-255-11 CERAMIC CHIP 150PF 5% 50V
C391 1-164-505-11 CERAMIC CHIP 2.2uF 16V
C392 1-164-505-11 CERAMIC CHIP 2.2uF 16V
C393 1-124-233-11 ELECT 10uF 20% 16V
C394 1-124-233-11 ELECT 10uF 20% 16V
C395 1-164-346-11 CERAMIC CHIP 1uF 16V
C396 1-164-346-11 CERAMIC CHIP 1uF 16V
C397 1-164-505-11 CERAMIC CHIP 2.2uF 16V
C398 1-164-505-11 CERAMIC CHIP 2.2uF 16V
C399 1-163-021-91 CERAMIC CHIP 0.01uF 10% 50V
C400 1-163-038-00 CERAMIC CHIP 0.1uF 25V
C402 1-163-037-11 CERAMIC CHIP 0.022uF 10% 25V
C403 1-163-037-11 CERAMIC CHIP 0.022uF 10% 25V
C404 1-164-346-11 CERAMIC CHIP 1uF 16V

16
Ref. No. Part No. Description Remarks Ref. No. Part No. Description Remarks
MDR-RF975R
< CERAMIC FILTER >
CF301 1-577-588-11 FILTER, CERAMIC
CF302 1-577-572-11 FILTER, CERAMIC
< DIODE >
D301 8-719-002-81 DIODE 1T363
D303 8-719-056-71 DIODE UDZ-TE-17-2.2B
D304 8-719-077-16 LED TLSU124(TPJ52) (power)
D310 8-719-975-40 DIODE RB411D
< IC >
IC301 8-752-072-12 IC CXA1538N
IC302 8-759-802-75 IC LA4533M
IC303 8-759-453-43 IC TC74HC4024AF(EL)
IC304 8-759-510-73 IC BA10393F-E2
IC305 8-759-083-94 IC TC7W74FU
IC306 8-759-344-00 IC NJM2100E(TE2)
IC307 8-759-384-90 IC TK10691M
IC308 8-759-384-90 IC TK10691M
IC309 8-759-344-00 IC NJM2100E(TE2)
< JUMPER RESISTER >
JC303 1-216-295-91 SHORT 0
JC304 1-216-295-91 SHORT 0
JC306 1-216-295-91 SHORT 0
JC309 1-216-295-91 SHORT 0
JC311 1-216-295-91 SHORT 0
JC331 1-216-295-91 SHORT 0
JC332 1-216-295-91 SHORT 0
JC333 1-216-295-91 SHORT 0
JC334 1-216-295-91 SHORT 0
JC335 1-216-295-91 SHORT 0
JC336 1-216-295-91 SHORT 0
JC350 1-216-295-91 SHORT 0
< COIL >
L301 1-422-317-31 COIL, AIR-CORE
L302 1-412-933-11 INDUCTOR 0.33uH
< TRANSISTOR >
Q301 8-729-903-10 TRANSISTOR FMW1
Q303 8-729-200-72 TRANSISTOR 2SC2712L-TE85L
Q304 8-729-200-72 TRANSISTOR 2SC2712L-TE85L
Q305 8-729-027-44 TRANSISTOR DTC114TKA-T146
Q306 8-729-200-72 TRANSISTOR 2SC2712L-TE85L
Q307 8-729-200-72 TRANSISTOR 2SC2712L-TE85L
< RESISTER >
R302 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R304 1-216-061-00 RES-CHIP 3.3K 5% 1/10W
R305 1-216-061-00 RES-CHIP 3.3K 5% 1/10W
R308 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R309 1-216-097-11 RES-CHIP 100K 5% 1/10W
R310 1-216-061-00 RES-CHIP 3.3K 5% 1/10W
R312 1-216-077-00 RES-CHIP 15K 5% 1/10W
R314 1-216-097-11 RES-CHIP 100K 5% 1/10W
R315 1-216-001-00 METAL CHIP 10 5% 1/10W
R316 1-216-001-00 METAL CHIP 10 5% 1/10W
R318 1-216-089-91 RES-CHIP 47K 5% 1/10W
R320 1-216-001-00 METAL CHIP 10 5% 1/10W
R321 1-216-053-00 METAL CHIP 1.5K 5% 1/10W
R322 1-216-069-00 METAL CHIP 6.8K 5% 1/10W
R325 1-216-037-00 METAL CHIP 330 5% 1/10W
R330 1-216-001-00 METAL CHIP 10 5% 1/10W
R331 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R332 1-216-049-11 RES-CHIP 1K 5% 1/10W
R333 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R334 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R340 1-216-071-00 METAL CHIP 8.2K 5% 1/10W
R341 1-216-113-00 METAL CHIP 470K 5% 1/10W
R342 1-216-106-00 METAL CHIP 240K 5% 1/10W
R343 1-216-099-00 METAL CHIP 120K 5% 1/10W
R344 1-216-092-00 RES-CHIP 62K 5% 1/10W
R345 1-216-084-00 METAL CHIP 30K 5% 1/10W
R346 1-216-077-00 RES-CHIP 15K 5% 1/10W
R347 1-216-070-00 METAL CHIP 7.5K 5% 1/10W
R348 1-216-089-91 RES-CHIP 47K 5% 1/10W
R349 1-216-073-00 RES-CHIP 10K 5% 1/10W
R350 1-216-077-00 RES-CHIP 15K 5% 1/10W
R351 1-216-121-11 RES-CHIP 1M 5% 1/10W
R352 1-216-121-11 RES-CHIP 1M 5% 1/10W
R353 1-216-077-00 RES-CHIP 15K 5% 1/10W
R354 1-216-081-00 METAL CHIP 22K 5% 1/10W
R355 1-216-089-91 RES-CHIP 47K 5% 1/10W
R356 1-216-081-00 METAL CHIP 22K 5% 1/10W
R357 1-216-081-00 METAL CHIP 22K 5% 1/10W
R358 1-216-081-00 METAL CHIP 22K 5% 1/10W
R360 1-216-081-00 METAL CHIP 22K 5% 1/10W
R361 1-216-081-00 METAL CHIP 22K 5% 1/10W
R362 1-216-073-00 RES-CHIP 10K 5% 1/10W
R363 1-216-081-00 METAL CHIP 22K 5% 1/10W
R364 1-216-081-00 METAL CHIP 22K 5% 1/10W
R366 1-216-029-00 METAL CHIP 150 5% 1/10W
R367 1-216-089-91 RES-CHIP 47K 5% 1/10W
R370 1-216-071-00 METAL CHIP 8.2K 5% 1/10W
R371 1-216-071-00 METAL CHIP 8.2K 5% 1/10W
R372 1-216-071-00 METAL CHIP 8.2K 5% 1/10W
R373 1-216-071-00 METAL CHIP 8.2K 5% 1/10W
R374 1-216-064-00 METAL CHIP 4.3K 5% 1/10W
R375 1-216-064-00 METAL CHIP 4.3K 5% 1/10W
R376 1-216-097-11 RES-CHIP 100K 5% 1/10W
R377 1-216-097-11 RES-CHIP 100K 5% 1/10W
R378 1-216-063-91 RES-CHIP 3.9K 5% 1/10W
R379 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R380 1-216-049-11 RES-CHIP 1K 5% 1/10W
R381 1-216-049-11 RES-CHIP 1K 5% 1/10W
R382 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R383 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R384 1-216-067-00 METAL CHIP 5.6K 5% 1/10W
R385 1-216-067-00 METAL CHIP 5.6K 5% 1/10W
R386 1-216-065-91 RES-CHIP 4.7K 5% 1/10W
R387 1-216-065-91 RES-CHIP 4.7K 5% 1/10W
R390 1-216-097-11 RES-CHIP 100K 5% 1/10W
R391 1-216-097-11 RES-CHIP 100K 5% 1/10W
R392 1-216-063-91 RES-CHIP 3.9K 5% 1/10W
R393 1-216-057-00 METAL CHIP 2.2K 5% 1/10W
R394 1-216-061-00 RES-CHIP 3.3K 5% 1/10W
R395 1-216-061-00 RES-CHIP 3.3K 5% 1/10W
R396 1-216-083-00 METAL CHIP 27K 5% 1/10W
RX-BASE
Ver 1.1 2001.06

17
Ref. No. Part No. Description Remarks Ref. No. Part No. Description Remarks
MDR-RF975R
R397 1-216-083-00 METAL CHIP 27K 5% 1/10W
R398 1-216-073-00 RES-CHIP 10K 5% 1/10W
R399 1-216-073-00 RES-CHIP 10K 5% 1/10W
R400 1-216-025-11 RES-CHIP 100 5% 1/10W
R401 1-216-025-11 RES-CHIP 100 5% 1/10W
R403 1-216-073-00 RES-CHIP 10K 5% 1/10W
R404 1-216-073-00 RES-CHIP 10K 5% 1/10W
< VARIABLE RESISTOR >
RV301 1-241-763-11 RES, ADJ, CARBON 4.7K (FREE RUN FREQ.)
RV302 1-227-189-11 RES, VAR CARBON 20K/20K (VOL )
< SWITCH >
S301 1-771-980-11 SWITCH, TACTILE (TUNE)
******************************************************
*1-678-658-11 RX-SW BOARD
***********
< SWITCH >
S302 1-572-467-61 SWITCH, PUSH (1 KEY) (POWER ON/OFF)
******************************************************
MISCELLANEOUS
*************
6 X-3380-120-1 DRIVER ASSY
8 1-756-109-11 BATTERY, NICKEL HYDROGEN
RX-BASE RX-SW
w

MDR-RF975R
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
1.1 2001.06 Correction of electrical adjustment and electrical parts list. (ENG-01007)
1.0 2001.05 New