For RM-X4S (Remote Commander),
please refer to RM-X4S Service Manual
(9-925-698-∏) previously issued.
Photo: MDX-C7970R
SPECIFICATIONS
US Model
Canadian Model
E Model
MDX-C7970
AEP Model
UK Model
MDX-C7970R
Model Name Using Similar Mechanism MDX-C7900/C7900R
Base Mechanism TypeMG-164N-138
Optical Pick-Up NameKMS-241B/J1NP
MICROFILM
– Continued on next page –
FM/AM(MW/LW) MINIDISC PLAYER
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic break-down because of the potential difference generated
by the charged electrostatic load, etc. on clothing and the human
body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
Never look into the laser diode emission from right avove when
checking it for adustment. It is feared that you will lose your sight.
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
(KMS-241B/J1NP)
The laser diode in the optical pick-up block may suffer electrostatic break-down easily. When handling it, perform soldering
bridge to the laser-tap on the flexible board. Also perform m easures
against electrostatic break-down suff iciently before the operation.
The flexible board is easily damaged and should be handled with
care.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED
LINE WITH MARK ! ON THE SCHEMA TIC DIAGRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFIÉS P AR UNE MARQUE !
SUR LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE
DES PIÈCES SONT CRITIQUES POUR LA SÉCURITÉ
DE FONCTIONNEMENT. NE REMPLACER CES COMPOSANTS QUE PAR DES PIÈCES SONY DONT LES
NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
laser-tap
OPTICAL PICK-UP FLEXIBLE BOARD
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.
Flexible Circuit Board Repairing
• Keep the temperature of the 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.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation exposure.
– 2 –
TABLE OF CONTENTS
1.GENERAL
Location of Controls ....................................................... 4
Resetting the Unit ........................................................... 5
Detaching the Front Panel............................................... 5
Preparing the Rotary Commander .................................. 5
Setting the Clock............................................................. 5
Using the Rotary Commander ........................................ 5
Adjusting the Sound Characterisitics ............................. 5
Attenuating the Sound .................................................... 5
Changing the Sound and Display Settings ..................... 6
Boosting the Bass Sound ................................................ 6
6.ELECTRICAL PARTS LIST ............................... 83
– 3 –
SECTION 1
GENERAL
This section is extracted from
instruction manual.
– 4 –
– 5 –
– 6 –
– 7 –
– 8 –
– 9 –
– 10 –
– 11 –
SECTION 2
w
DISASSEMBLY
Note: Follow the disassembly procedure in the numerical order given.
SUB PANEL ASS’Y
2
two claws
4
sub panel ass’y
1
three screws
(PTT2.6 × 6)
2
cla
MECHANISM DECK (MG-164N-138)
3
mechanism deck
(MG-164N-138)
2
connector
(CN200)
3
connector
(CN901)
1
two screws
(PTT2.6
1
screw
(PTT2.6 × 6)
×
4)
– 12 –
MAIN BOARD, HEAT SINK
d
2
three screws
(PTT2.6 × 6) (ground point)
3
main board
4
insulating sheet
5
eight screws
(PTT2.6 × 10)
6
heat sink
1
two screws
(PTT2.6 × 10)
SERVO BOARD
1
2
two screws
(BVTT2
×
4)
sensor flexible board
(CN102)
2
two screws
(BVTT2
×
4)
3
servo board
1
flexible boar
(CN103)
– 13 –
MD COVER ASS’Y
)
3
MD cover ass’y
shaft (MD cover guide)
cassette holder
1
four screws
(B2
×
3)
FLOAT BLOCK
float block
A
2
Pushing the Cassette Holder toward the direction A with a
screwdriver, etc., disengage the Shaft (MD Cover Guide) from
the slot in the MD Cover Ass’y.
Note:Take care not to scratch the Optiocal Pick-up when pushing
the Cassette Holder with a screwdriver. etc.
3
Pushing an arrow A part, raise the float block
up ward at the front to release a lock.
1
A
tension spring (FL2)
lever (lock R)
lever (lock L)
2
two tension springs (FLOAT F)
– 14 –
1
tension spring (FL2
LO MOTOR ASS’Y (LOADING) (M903)
4
Remove the bracket (LO)
in the direction of the arrow
A
.
LEVER (LE) ASS’Y
1
Remove solders of motor. (M903)
A
5
LO motor ass’y (loading)
(M903)
2
tension spring (rack)
3
claw
2
stopper washer
1
3
roller (GLE)
2
lever (LE) ass’y
– 15 –
HOLDER ASS’Y
2
type-E stop ring 1.5
3
2
type-E stopring 1.5
1
spring (CHKG)
lever (lock R)
3
lever (lock L)
4
Remove the holder ass’y in the
direction of the arrow.
2
2
type-E stop ring 1.5
type-E stop ring 1.5
1
spring (CHKG)
CHUCKING ARM ASS’Y
holder ass’y
1
Remove the chucking arm ass’y
in the direction of the arrow.
– 16 –
OPTICAL PICK-UP (KMS-241B/J1NP)
y
4
screw
(P1.7 × 1.8)
5
bracket (SL)
9
two screws
(P1.7 × 1.8)
!º
retainer (SP)
!¡
SP motor ass’y
(spindle) (M901)
7
screw
(B2 × 3)
2
two screws
(2 × 8)
3
sensor board
1
Remove solders of motors.
(M901, M902)
8
base (SL)
6
SL motor ass’y
(sled) (M902)
7
optical pick-up
(KMS-241B/J1NP)
1
two screws
(K2 × 3)
2
shaft (SL2)
4
screw
(B2 × 3)
6
bearing (SL)
5
feed screw ass’
3
screw
(K2 × 3)
SL MOTOR ASS’Y (SLED) (M902), SP MOTOR ASS’Y (SPINDLE) (M901)
– 17 –
SECTION 3
ELECTRICAL ADJUSTMENTS
TEST MODE
This set have the test mode function. In the test mode, FM Auto
Scan/Stop Level and AM (MW) Auto Scan/Stop Lev el adjustments
can be performed easier than it in ordinary procedure.
<Set the Test Mode>
1. Turn ON the regulated po wer supply . ( The clock is displayed)
Note: Press the [OFF] button, if the clock is not displayed.
2. Push the preset [4] button.
3. Push the preset [5] button.
4. Press the preset [1] button for more than two seconds.
5. Then the display indicates all lights, the test mode is set.
<Release the Test mode>
1. Push the [OFF] button.
See the adjustment location from on page 22 for the adjustment.
MD SECTION
MD section adjustments are done automatically in this set.
TUNER SECTION
0 dB=1 µV
Cautions during repair
When the tuner unit is defective, replace it by a new one because its internal block is difficult to repair.
Note: Adjust the tuner section in the sequence shown below.
1. FM Auto Scan/Stop Level Adjustment
2. FM Stereo Separation Adjustment (MDX-C7970)
3. FM Stereo Separation Adjustment (Wide) (MDX-C7970R)
4. FM Stereo Separation Adjustment (Narrow) (MDX-C7970R)
5. FM RDS S-Meter Adjustment (MDX-C7970R)
6. AM (MW) Auto Scan/Stop Level Adjustment
FM Auto Scan/Stop Level Adjustment
Setting:
[SOURCE] button: FM
FREQUENCY SELECT switch: FM 200 k (E model)
FM RF signal
generator
Carrier frequency: 97.9 MHz (MDX-C7970)
Output level: 22 dB (12.6
3. Adjust the volume RV2 on TU1 by turning clockwise untill
“0” is shown next to “FM” on the display window, If “0” is
already shown or the volume RV2 has been turned too far,
turn it back counterclockwise untill “0” is disappeared once,
then try this adjustment.
1. Adjust the volume RV3 on FM/AM tuner unit (TU1) for the
best separation.
FM Stereo
signal generator
output channel
L-CHL-CHA
L-CHR-CHAdjust RV3 on TU1
R-CHR-CHC
R-CHL-CHD
Level meterLevel meter
connectionreading (dB)
for minimum reading.
L-CH Stereo separation: A-B
R-CH Stereo separation: C-D
The separations of both channels should be equal.
Specification: Separation more than 24 dB
Ω
level meter
+
–
B
Adjustment Location: See page 22.
– 19 –
FM Stereo Separation Adjustment (Narrow)
(MDX-C7970R)
Setting:
[SOURCE] button : FM
[SHIFT] button: ON (light up SET UP and PLAY MODE)Preset [4] (PLAY MODE) →
[5] (→) buttons: NARROW mode
FM RF signal
generator
antenna jack (J1)
0.01 µF
(75
Ω)
10 k
set
Ω
level meter
FM RDS S-Meter Adjustment (MDX-C7970R)
Setting:
[SOURCE] button : FM
FM RF signal
generator
Carrier frequency: 98.00 MHz
+
–
Output level: 35 dB (56.2
Mode: mono
Modulation: no modulation
antenna jack (J1)
µ
F
0.01
µ
V)
set
Carrier frequency : 98.00MHz
Output level: 70 dB (3.2 mV)
Mode: stereo
Modulation: main: 1 kHz, 20 kHz deviation (26.7%)
sub : 1 kHz, 20 kHz deviation (26.7%)
: 19 kHz pilot: 7.5 kHz deviation (10%)
LINE OUT jack (CNP300)
Procedure:
1. Adjust the volume RV4 on FM/AM tuner unit (TU1) for the
best separation.
FM Stereo
signal generator
output channel
L-CHL-CHA
L-CHR-CHAdjust RV4 on TU1
R-CHR-CHC
R-CHL-CHD
Level meterLevel meter
connectionreading (dB)
B
for minimum reading.
L-CH Stereo separation: A-B
R-CH Stereo separation: C-D
The separations of both channels should be equal.
Specification: Separation more than 18 dB
Adjustment Location: See page 22.
Procedure:
1. Set to the test mode. (See page 18)
2. Push the
[SOURCE] button and set to FM.
Display
SHUF
3. Push the preset
[10] button .
4. Adjust RV1 on MAIN board so that the display indication is
“13.2”.
Display
SHUF
Specification: Display indication: 13.0 to 13.4
Adjustment Location: See page 22.
– 20 –
MW Auto Scan/Stop Level Adjustment
(
)
Setting:
[SOURCE] n [MODE] button : AM (MDX-C7970)
MW (MDX-C7970R)
FREQUENCY SELECT switch : AM 10 k (E model)
30
AM RF signal
generator
AM dummy antenna
(50 Ω)
antenna jack (J1)
Carrier frequency : 1000 kHz (MDX-C7970)
30% amplitude
modulation by
1 kHz signal
Output level: 33 dB
Procedure:
1. Set to the test mode. (See page 18)
2. Push the
3. Push the
[SOURCE] button and set to FM.
[MODE] button and set to AM or MW.
999 kHz (MDX-C7970R)
44.7 µV
Ω
15 pF
65 pF
set
Adjustment Location:
– SET UPPER VIEW –
RV1 RDS S-Meter Adjustment (MDX-C7970R)
TU1
RV1 AM (MW) Auto Scan/Stop Level Adjustment
RV2 FM Auto Scan/Stop Level Adjustment
RV3 FM Stereo Separation Adjustment (Wide) (MDX-C7970R)
FM Stereo Separation Adjustment (MDX-C7970)
RV4
FM Stereo Separation Adjustment (Narrow) (MDX-C7970R)
Display
*2
TP
*4
SHUF
*3
4. Adjust with the volume RV1 on TU1 so that the “ AM” or “MW”
indication turns to “AM0” or “MW0” indication on the display window.
But, in case of alredy indicated “AM0” or “MW0”, turn the
RV1 so that put out light “0” indication and adjustment.