Sony MDX-C7900 / MDX-C7900R Service Manual ▷ View online
– 17 –
MOTOR ASS’Y (M901, M902, M903), SENSOR BOARD
1
Remove the solders
of motor (M901, M902, M903).
of motor (M901, M902, M903).
3
sensor board
2
two screws
(2
(2
×
8)
8
base (SL)
7
screw
(B2
(B2
×
3)
6
motor ass’y
(M902)
(M902)
5
bracket (SL)
4
screw
(P1.7
(P1.7
×
1.8)
!¡
screw
(P2
(P2
×
2.2)
!™
motor ass’y
(M903)
(M903)
0
motor ass’y
(M901)
(M901)
9
two screws
(P1.7
(P1.7
×
1.8)
– 18 –
SECTION 4
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 Level adjustments
can be performed easier than it in ordinary procedure.
Scan/Stop Level and AM (MW) Auto Scan/Stop Level adjustments
can be performed easier than it in ordinary procedure.
<Set the Test Mode>
1. Set the “power select” switch (S700) is “A (ON)” position.
2. Turn ON the regulated power supply. (All LEDs on the set
1. Set the “power select” switch (S700) is “A (ON)” position.
2. Turn ON the regulated power supply. (All LEDs on the set
lights up, and the clock is displayed.)
Note:
Press the
[OFF]
button, if the clock is not displayed.
3. Push the preset
[4]
button.
4. Push the preset
[5]
button.
5. Press the preset
[1]
button for more than two seconds.
6. Then the display indicates all lights, the test mode is set.
<Release the Test mode>
1. Push the
1. Push the
[OFF]
button.
2. Return the “power select” switch (S700) to initially set posi-
tion.
MD SECTION
MD section adjustments are done automatically in this set.
TUNER SECTION
Note:
Adjust the tuner section in the sequence shown below.
1. FM Auto Scan/Stop Level Adjustment.
2. FM Stereo Separation Adjustmnet.
3. AM (MW) Auto Scan/Stop Level Adjustment.
4. RDS S-Meter Adjustment.
2. FM Stereo Separation Adjustmnet.
3. AM (MW) Auto Scan/Stop Level Adjustment.
4. RDS S-Meter Adjustment.
FM Auto Scan/Stop Level Adjustment
Setting:
[SOURCE]
button: FM
Procedure:
1. Set to the test mode.
2. Push the
1. Set to the test mode.
2. Push the
[SOURCE]
button and set to FM.
Display
0 dB=1 µV
See the adjustment location from on page 20 for the ad-
justment.
justment.
Cautions during repair
When the tuner unit is defective, replace it by a new one be-
cause its internal block is difficult to repair.
cause its internal block is difficult to repair.
3. Adjust with the volume RV2 on TU1 so that the “FM” indica-
tion turns to “FM0” indication on the display window.
But, in case of already indicated “FM0”, turn the RV2 so that
put out light “0” indication and adjustment.
But, in case of already indicated “FM0”, turn the RV2 so that
put out light “0” indication and adjustment.
Display
*1: MDX-C7900R is indicates “98.00”.
Adjustment Location: See page 20.
FM Stereo Separation Adjustment
Setting:
[SOURCE]
button: FM
Procedure:
L-CH Stereo separation: A-B
R-CH Stereo separation: C-D
The separations of both channels should be equal.
R-CH Stereo separation: C-D
The separations of both channels should be equal.
Specification: Separation more than 30 dB
Adjustment Location: See page 20.
FM RF signal
generator
Carrier frequency: 97.9 MHz (MDX-C7900)
98.0 MHz (MDX-C7900R)
Output level
: 22 dB (12.6
µ
V)
Mode
: mono
Modulation
: 1 kHz, 22.5 kHz deviation (30%)
0.01
µ
F
set
antenna jack (J1)
SHUF
REG
*1
SHUF
REG
*1
FM RF signal
generator
0.01
µ
F
set
antenna jack (J1)
+
–
–
speaker out terminal
level meter
4
Ω
MDX-C7900
MDX-C7900R
Carrier frequency
97.9 MHz
98.0 MHz
Output level
60 dB (1 mV)
70 dB (3.2 mV)
Mode
stereo
stereo
main
1 kHz, 33.75 kHz
1 kHz, 20 kHz
deviation (45%)
deviation (22.6%)
Modulation
sub
1 kHz, 33.75 kHz
1 kHz, 20 kHz
deviation (45%)
deviation (22.6%)
19 kHz
7.5 kHz
7.5 kHz
pilot
deviation (10%)
deviation (10%)
FM Stereo
Level meter
Level meter
signal generator
connection
reading (dB)
output channel
L-CH
L-CH
A
B
R-CH
L-CH
Adjust RV4 on TU1
for minimum reading.
R-CH
R-CH
C
D
L-CH
R-CH
Adjust RV4 on TU1
for minimum reading.
RDS S-Meter Adjustment (MDX-C7900R)
Setting:
[SOURCE]
button: FM
Procedure:
1. Set to the test mode. (See page 18.)
2. Push the
1. Set to the test mode. (See page 18.)
2. Push the
[SOURCE]
button and set to FM.
Display
3. Push the preset
[10]
button.
4. Adjust RV1 on MAIN board so that the display indication is
“15.8”.
Display
Specification: Display indication : 15.6 to 16.4
Adjustment Location: See page 20.
AM (MW) Auto Scan/Stop Level Adjustment
Setting:
[SOURCE]
button (MDX-C7900): AM
[SOURCE]
button (MDX-C7900R): MW
Procedure:
1. Set to the test mode. (See page 18.)
2. Push the
1. Set to the test mode. (See page 18.)
2. Push the
[SOURCE]
button and set to FM.
3. Push the
[MODE]
button and set to AM (MDX-C7900) or MW
(MDX-C7900R).
Display
4. Adjust with the volume RV1 on TU1 so that the “AM” or “MW”
indication turns to “AM0” or “MW0” indication on the dis-
play window.
But, in case of already indicated “AM0” or “MW0”, turn the
RV1 so that put out light “0” indication and adjustment.
play window.
But, in case of already indicated “AM0” or “MW0”, turn the
RV1 so that put out light “0” indication and adjustment.
Display
*2: MDX-C7900R is indicates “MW”.
*3: MDX-C7900R is indicates “999”.
*3: MDX-C7900R is indicates “999”.
Adjustment Location: See page 20.
– 19 –
– 20 –
AM RF signal
generator
Carrier frequency: 1000 kHz (MDX-C7900)
999 kHz (MDX-C7900R)
30% amplitude
modulation by
1 kHz signal
Output level
modulation by
1 kHz signal
Output level
: 33 dB (44.7
µ
V)
set
AM dummy antenna
(50
(50
Ω
)
30
Ω
15 pF
65 pF
antenna jack (J1)
SHUF
REG
*3
*2
TP
SHUF
REG
*3
*2
TP
FM RF signal
generator
Carrier frequency: 98.0 MHz
Output level
Output level
: 35 dB (56.2
µ
V)
Mode
: mono
Modulation
: no modulation
0.01
µ
F
set
antenna jack (J1)
SHUF
REG
SHUF
REG
Adjustment Location:
– SET UPPER VIEW –
RV1 RDS S-METER Adjustment
TU1
RV1 AM (MW) AUTO SCAN/STOP LEVEL Adjustment
RV2 FM AUTO SCAN/STOP LEVEL Adjustment
RV4 FM STEREO SEPARATION Adjustment
MDX-C7900/C7900R
– 21 –
– 22 –
5-1.
BLOCK DIAGRAM – SERVO Section –
F
C
B
D
A
E
I
J
J
I
B
A
C
D
D
E
F
DETECTOR
1
2
J
I
4
5
6
7
A
B
C
D
D
8
9
E
F
LD
PD
LASER DIODE
ILCC
PD
OPTICAL PICK-UP
(KMS-241A/J2N)
AUTOMATIC
POWER
CONTROL
Q302
11
10
APC
PD
LD/PD
AMP
12
APCREF
I-V
AMP
I-V
AMP
AT
AMP
B.P.F.
29
30
WBL
ADFM
ADIN
32
ADFG
ABCD
AMP
FOCUS
ERROR AMP
TRACKING
ERROR AMP
35
34
26
28
ABCD
FE
TE
SE
V-I
CONVERTER
20
F0CNT
WBL
3T
EQ
+3.3V
SERIAL/
PARALLEL
CONVERTER,
DECODER
COMMAND
17
16
18
SWDT
SCLK
XLAT
RF AMP
B.P.F.
46
RFO
40
RF AGC
& EQ
AGCI
EQ
38
RF
RF AMP,
FOCUS/TRACKING ERROR AMP
IC302
TEMP
48 47
MORFO
MORFI
3T
PEAK &
BOTTOM
WBL
33
AUX
73 62
37
PEAK
36
BOTM
FOCUS/TRACKING COIL DRIVE,
SPINDLE/SLED MOTOR DRIVE
IC303
6
8
OUT4F
OUT4R
M
M901
(SPINDLE)
27
25
OUT2F
OUT2R
M
M902
(SLED)
21
23
OUT1F
OUT1R
12
10
OUT3F
OUT3R
FCS+
FCS–
TRK+
TRK–
2-AXIS
DEVICE
(TRACKING)
(FOCUS)
3
4
IN4R
IN4F
29
30
IN2F
IN2R
19
18
IN1F
IN1R
14
15
IN3F
IN3R
SPFD
SPRD
IC306
92
91
88
89
86
85
83
APCREF
SFDR
SRDR
FFDR
FRDR
TFDR
TRDR
16
PSB
PWM GENERATOR
AUTOMATIC
POWER
CONTROL
DIGITAL
SERVO
SIGNAL
PROCESS
74
65
64
75
66
63
ANALOG MUX
A/D CONVERTER
AUTO
SEQUENCER
13
FROM CPU
INTERFACE
DIGITAL SERVO
SIGNAL PROCESSOR
IC301 (2/2)
RECP
PEAK HOLD
Q301
+3.3V
ABCD
AUX1
AUX2
ABCD
FE
TE
SE
PEAK
BOTM
81
80
82
XLRF
CKRF
DTRF
EFM/ACIRC
ENCODER/DECODER
SHOCK PROOF
MEMORY CONTROLLER
ATRAC
ENCODER/DECODER
PLL
FILTER
59
58
61
60
FILI
PCO
CLTV
FILO
100
EFMO
23
ADDT
IC301 (1/2)
15
TX
COMPA-
RATOR
51
52
55
ASYO
ASYI
RFI
ADIP
DEMODULATOR/
DECODER
78
ADFG
SPINDLE
SERVO
79
F0CNT
94 93
SPFD
SPRD
SUBCODE
PROCESSOR
24
SAMPLING
RATE
CONVERTER
DIGITAL
AUDIO
INTERFACE
22
21
DIN
DOUT
DIGITAL SIGNAL PROCESSOR,
EFM/ACIRC ENCODER/DECODER,
SHOCK PROOF MEMORY CONTROLLER,
ATRAC ENCODER/DECODER, 2M BIT D-RAM
IC301 (1/2)
DADT
INTERNAL BUS
D-RAM
CLOCK
GENERATOR
25
26
27
512FS OSC
IC304
XBCK
LRCK
FS256
BCK
LRCK
FS256
X301
22.5792MHz
22.5792MHz
16
OSCI
17
OSCO
CPU
INTERFACE
MONITOR
CONTROL
CONTROL
10
XRST
12
DQSY
11
SQSY
14
XINT
9 8
5 6 7
SENS
SRDT
SWDT
SCLK
XLAT
LEVEL SHIFT
IC502
5
13
3 1
6
12
4 2
LEVEL SHIFT
IC503
1
2
3
4
MNT0
MNT1
MNT2
MNT3
13
1
3
5
12
2
4
6
FOK
SHOCK
XBUSY
SLOCK
SWDT
SCLK
XLAT
59
62
55
54 52
45 51 64
26 27 28 29
MNT0
MNT1
MNT2
MNT3
21
LOCK
39
TEMP
MD-RST
SQSY
CC-XINT
SENS
MD-SI
MD-SO
MD-CKO
MD-LAT
7
6
EJECT
LOAD
5
4
05
1
7
M
RIN
FIN
OUT1 OUT2
LOADING
MOTOR DRIVE
IC305
M903
(LOADING)
63
C-SW
LOADING START/
EJECT END
EJECT END
E-SW
LOADING
END
END
LIMIT-IN
(LIMIT)
ON: When the disc loading start
and thedisc eject completion.
ON: When the optical pick-up is
inner position.
(ON: When completion of the disc loading.)
31
32
EXTAL
XTAL
X501
10MHz
TH501
47, 46, 48, 49
1, 2, 24, 25
D0 – D3
32 – 29, 34 – 38, 43
9 – 12, 14 – 18, 5
A0 – A9
D0 – D3
A00 – A09
41
22
45
3
44
4
42
23
XOE
XWE
XRAS
XCAS
OE
WE
RAS
CAS
D-RAM
IC307
A
DADT
(Page 5)
(Page 5)
B
BCK, LRCK, FS256
(Page 5)
C
LOCK
MD MECHANISM CONTROLLER
IC501 (1/2)
• SIGNAL PATH
: MD PLAY
11
56
SECTION 5
DIAGRAMS
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