Sony MDRRF-975-R Service manual
MDR-RF975R
SERVICE MANUAL
Ver 1.1 2001. 06
MDR-RF975R is the component model block one in the MDR-RF975RK.
COMPONENT MODEL NAME FOR MDR-RF975RK
Headphones MDR-RF975R
Transmitter TMR-RF975R
US Model
SPECIFICATIONS
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.
9-873-141-12
2001F0200-1
© 2001.6
HEADPHONES
Sony Corporation
Personal Audio Company
Shinagawa Tec Service Manual Production Group
MDR-RF975R
SECTION 1
GENERAL
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
This section is extracted from
instruction manual.
5
Turn 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.
TUNING
button
VOL control
Try the above steps 3 and 5 until the
receiving performance becomes better.
6. ELECTRICAL PARTSLIST..................................... 15
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.
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.
2
SECTION 2
DISASSEMBLY
• The equipment can be removed using the following procedure .
MDR-RF975R
Set
Driver (R side), RX-BASE board
Driver (L side), Hanger (L)
SW board, Harger (R)
Holder (L)
Note: Follow the disassembly procedure in the numerical order given .
2-1. DRIVER (R SIDE), RX-BASE BOARD
9
Volume knob
Holder (R)
Set the each leads as illustrated below.
From head
band assy (front).
From head
band assy (rear).
Groove
From
SW board.
Groove
qa
RX-BASE board
0
Remove the
eight solderings.
(Housing (R) side)
Head band
assy (front)(natural)
8
Charge terminal
7
Remove the
two solderings.
Precaution for installtion
ANT
RX-BASE board
SW board
Head band
assy (rear)(natural)
Head band
assy (rear)(green)
Driver (natural)
Driver (red)
4
Holder (R),ear pad
5
Remove the
two solderings.
6
Four
claws
Driver
2
Four screws (M 2
Housing (R)
Precaution for installtion
3
Plate (R) assy, front
1
pad, ear
× 5)
Precaution for installtion
Driver (R side)
Head band
assy (front)(red)
Solder the each leads directly to the position as shown
while being cautions of colors.
SW board
Red Natural
From RX-BASE board.
3
MDR-RF975R
s
2-2. SW BOARD, HANGER (R)
1
1
2
Housing (R)
Precaution for installtion
3
Lid (R), hanger
8
7
Remove the
two solderings.
SW board
5
Holder (R)
4
Two screw
(P 2
× 8)
Set the each leads as illustrated below.
Groove
Groove
Groove
From head
band assy (front).
From head
band assy (rear).
2-3. HOLDER (R)
2
Spring
(ON/OFF)
From
SW board.
Groove
Groove
Groove
Hanger (R)
3
Holder (R)
SW board
9
6
4
Cushion assy, head
8
Band assy (front), Head
7
Band assy (rear), head
Hanger (R)
5
1
Screw (P 2
× 8)
Two screws
× 8)
(P 2
6
Chassis
4
2-4. DRIVER (L SIDE)
Set the each leads as illustrated below.
MDR-RF975R
From head
band assy (front).
Groove
Groove
Housing (L)
Precaution for installtion
3
Plate (L) assy, front
1
Pad, ear
2
Four screws (M 2
Precaution for installtion
× 5)
Driver (L side)
From head
band assy (rear).
8
Driver
Four
claws
7
Remove the
two solderings.
4
Two "batterys,
nickle hydrogen"
6
Ear pad
holder (L)
Green
Natural
5
Remove the
two solderings.
Green Natural
From head band assy (rear).
5
MDR-RF975R
s
2-5. HANGER (L)
1
3
Lid (L), hanger
1
2
Housing (L)
Precaution for installtion
4
Two screws
(M 2
× 5)
5
Holder (L)
Set the each leads as illustrated below.
Hanger (L)
2-6. HOLDER (L)
Groove
From head
band assy (front).
From head
band assy (rear).
Groove
Groove
7
Hanger (L)
3
Cushion assy, head
2
Holder (L)
6
6
Band assy (front),head
7
Band assy
(rear), head
5
Chassi
1
Screw (M 2
× 5)
4
Two screws
(M 1.7
× 3)
6
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