Sony MDRRF-450 Service manual
MDR-RF430/RF450
SERVICE MANUAL
Ver 1.0 1998.06
Illustration : MDR-RF430
MDR-RF430 is the component model block one in the MDR-RF430RK.
MDR-RF450 is the component model block one in the MDR-RF450RK.
COMPONENT MODEL NAME FOR MDR-RF430RK/RF450RK
MDR-RF430RK MDR-RF450RK
Wireless Headphones MDR-RF430 MDR-RF450
Transmitter TMR-RF450R TMR-RF450R
AEP Model
Illustration : MDR-RF450
SPECIFICATIONS
Headphone
Charging and using hours
Approx. charging hours Approx. using time*
1 50 minutes
24** 20 hours
* at 1kHz 1mW + 1mW output
** the hours required to fully charge empty batteries
Battery life
Battery Approx. hours*
Sony alkaline battery LR6 (SG) 60
Sony battery R6P (SR) 30
* at 1kHz 1mW + 1mW output
Power source DC 3V : 2 x R6 (size AA) battery or 2 x supplied
Mass Approx. 215g (7.6oz.) incl.Ni-Cd batteries (MDR-RF430RK)
Supplied Ni-Cd rechargeable batteries
Model name NC-AA-HJ
Voltage 1.2V
Capacity 600mAh
Design and specifications are subject to change without notice.
NC-AA-HJ Ni-Cd rechargeable battery
Approx. 265g (9.4oz.) incl.Ni-Cd batteries (MDR-RF450RK)
WIRELESS STEREO HEADPHONES
MICROFILM
SECTION 1
d
)
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
MDR-RF430
1-1. RX BOARD, FE BOARD, RECEIVER (R-CH), SUSPENDER REMOVAL
Head band
5
RX board
FE board
4
8
9
Screw
(M1.7x4)
Spacer
!¶
Suspender
Hanger (R)
Hanger cover (R)
RX shield plate
7
Remove
solder
6
SW1
!™
Screw
+P 2x6
!º
!¡
!£
Ball shaft holder
MDD02 (R-CH)
2
3
Screws +P 2x5
Housing (R) assy
!∞
1-2. BATTERY CASE, RECEIVER (L-CH), SUSPENDER REMOVAL
Head band
Screws +P 2x10
!¢
Screw (M 1.7x4)
1
!§
Remove solder
Ear pa
Battery cover
9
Screw (M 1.7x4)
Ear pad
2
Screws +P 2x10
3
MDD01 (L-CH)
1
Suspender
Screws +P 2x5
!º
!¡
Remove solder
!™
8
Housing (L) assy
– 2 –
5
6
Ball shaft holder
Hanger (L)
4
7
Screw +P 2x6
Battery case
Hanger cover (L
MDR-RF450
r
1-1. RECEIVER (R-CH), RX BOARD, FE BOARD, SUSPENDER ASSY REMOVAL
Head band
!£
Remove
Hanger (R)
solder
RX board
8
9
Surpport switch
!¶
SW
board
9
Housing (R)
RX shield plate
MDD02 (R-CH)
0
!¢
FE board
3
Remove
solder
Front plat (R) assy
5
!™
!¡
Screw
(M1.7x4)
4
Claw
2
Screws
(M 1.7x4)
1-2. RECEIVER (L-CH), SUSPENDER ASSY REMOVAL
Head band
!∞
1
!§
7
Screws (M1.7x4)
Suspender
6
Screws +P 2x8
Hanger cover (R)
Ear pad
Ear pad
Suspender
9
Screws +P 2x8
0
Screws (M 1.7x4)
MDD01 (L-CH)
Claw
4
1
2
Screws
(M 1.7x5) tapping
Hanger cover (L)
!™
6
!¡
5
3
Remove solder
Front plate (L) assy
8
Battery cove
7
Hanger (L)
6
Housing (L)
– 3 –
SECTION 2
ELECTRICAL ADJUSTMENTS
Note :
1. Use transmitter with check and adjustment already completed.
2. The transmitter section adjustments should be completed before
performing the headphones section adjustment.
3. On adjusting the headphones section, use the transmitter as a
jig.
Headphones Transmitter
MDR-RF430
MDR-RF450
Setting :
AF OSC
1. Feed a signal to jig (transmitter) and connect a power supply to
DC IN 9V jack (J404).
TMR-RF450R
L-CH (J403)
1kHz 316mVrms (–7.8dB)
ATT
600
Ω
Jig
Transmitter
J404
power supply
(DC 11V)
Separation check and adjustment
1. Set the transmitter channel to CH2.
2. Set the transmitter noise filter SW to OFF .
3. Input a signal of 1kHz 316mVrms to onl y the transmitter L-c h
(J403).
4. Connect an digital voltmeter (AC range) and oscilloscope to
the L-ch speaker outputs (both sides of MDD01).
5. Receive signals b y turning the TUNING V OL (RV302).
6. Adjust the VOL (RV301) so that the RX boar d L-c h speaker
outputs (both sides of MDD01) are 155mVrms.
7. Connect an digital voltmeter (AC range) and oscilloscope to
the R-ch speaker outputs (both sides of MDD02) and measure
the voltages.
8. At this time, check to make sure the level separation of L-ch
and R-ch speaker outputs is more than 20dB. If the separation
is less than 20dB, turn R V303 on the RX boar d so that the R-c h
output is minimal, then check to see if the level separation of Lch and R-ch speaker outputs is more than 20dB.
9. Input a signal of 1kHz 316mVrms to onl y the transmitter R-c h
(J402).
10. Adjust the V OL (RV301) so that the RX boar d R-c h speaker
outputs (both sides of MDD02) are 155mVrms.
11. Connect an digital voltmeter (AC range) and oscilloscope to
the L-ch speaker outputs (both sides of MDD01) and measure
the voltages.
12. At this time, check to make sure the level separation of L-ch
and R-ch speaker outputs is more than 20dB.
Receive frequency check and adjustment
1. Set the transmitter channel to CH2.
2. Set the transmitter noise filter SW to OFF .
3. Input a signal of 1kHz 316mVrms to onl y the transmitter L-c h
(J403).
4. Place transmitter and headphones at a distance of more than 5m
apart.
5. Set the V OL (RV301) to MIN.
6. Position RX boar d TUNING V OL (RV302) to the center .
7. Connect a digital voltmeter (DC range) and an oscilloscope between IC301 pin @¡ and GND.
8. First check to make sure that a demodulated waveform of 1kHz
(appr oximatel y 13mVrms) is outputted to the oscilloscope , then
chec k to make sure the DC v oltmeter reading is DC 1–1.2V .
9. If a demodulated waveform of 1kHz is not outputted to the oscilloscope or if the DC level is not within the range specified
above, adjust the RX board L301 so that a demodulated waveform of 1kHz is outputted to the oscilloscope and while the waveform is outputted, further fine adjust the L301 so that the DC
voltmeter reading is DC 1.1V .
10. When completed, make sure signals can be received when switching the transmitter channel to CH1 or CH3 by turning RX board
TUNING V OL (RV302).
Connection points and Adjustment Location :
RX board (See page 5)
Connection points and Adjustment Location :
RX board (See page 5)
– 4 –
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