Sony CDX-838 Service Manual ▷ View online
13
OPERATION CHECK
1
Confirm that the slider moves in direction
C
to move down
the chuck plate if the gear (LOAD CAM) is rotated in direction
A
or
the chuck plate moves up and the slider moves in direction
D
if the
gear is rotated in direction
B
.
chuck plate
slider
gear (LOAD CAM) ass'y
A
B
C
D
14
SECTION 5
MECHANICAL ADJUSTMENTS
• Elevator Height (Address) Adjustment
Note:
This adjustments is necessary when the system controller (IC201),
variable resistor (RV201), slider (R), slider (L), or chassis (ELV)
was replaced for any repair.
variable resistor (RV201), slider (R), slider (L), or chassis (ELV)
was replaced for any repair.
Connection:
Adjustment Method:
1. Connect this set to the master unit (e.g. MDX-C7970/C7970R),
1. Connect this set to the master unit (e.g. MDX-C7970/C7970R),
load a disc magazine, and place the set vertically as shown
below.
below.
2. Connect the regulated power supply to the master unit, and
turn the power on.
3. Press the DISC button on the master unit and select DISC 5.
4. At this time, if the elevator shaft does not position between
comb teeth A and B at addresses 5 and 6 as shown below,
adjust the following.
adjust the following.
5. Press repeatedly the DISC + and – buttons on the master unit
so that the elevator shaft moves from address 6 to address 5, or
from 5 to 6. At this time, adjust RV201 on the main board so
that the elevator shaft positions smoothly between comb teeth
A and B.
from 5 to 6. At this time, adjust RV201 on the main board so
that the elevator shaft positions smoothly between comb teeth
A and B.
6. Further, place the set horizontally and make same adjustment
as mentioned above.
7. After adjustment at addresses 5 to 6 is finished, check all op-
erations from addresses 1 to 10 with the set placed vertically
and horizontally respectively to confirm that the elevator shaft
positions in a range between comb teeth A to B.
and horizontally respectively to confirm that the elevator shaft
positions in a range between comb teeth A to B.
comb tooth at address 6
elevator shaft
comb tooth at address 6
comb tooth at address 5
RV201
OK
NG
elevator shaft
comb tooth at address 5
A
B
A
B
power supply
GND
+
BUS cable
CDX-838
master unit
15
15
• FOCUS GAIN ADJUSTMENT
(COARSE ADJUSTMENT)
(COARSE ADJUSTMENT)
This adjustment is to be performed when replacing the following
parts.
• Optical Pick-up Block
• RV14
parts.
• Optical Pick-up Block
• RV14
– RF BOARD (Conductor Side) –
Procedure:
1. Set RV14 (RF board) to the standard position.
2. Check that there is not an abnormal amount of operation noise
1. Set RV14 (RF board) to the standard position.
2. Check that there is not an abnormal amount of operation noise
(white noise) from the 2-axis devise. If there is, turn RV14
slightly clockwise.
slightly clockwise.
– RF BOARD (Conductor Side) –
• When gain is lowered...
The set does not play because of no focus operation.
• When gain is highered...
Operation noise is heard due to a scratch or a dust, then opera-
tion will be unstable.
tion will be unstable.
RV14
IC11
IC51
CNJ12
MIN side
(low gain)
(low gain)
MAX side
(high gain)
(high gain)
RV14 standard position
SECTION 6
ELECTRICAL ADJUSTMENTS
Note:
1.
Perform adjustments as given.
2.
Power supply voltage: DC14.4 V (more than 3A).
• FOCUS BIAS CHECK
– RF BOARD (Conductor Side) –
Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VC) on the RF
1. Connect the oscilloscope to TP (RF) and TP (VC) on the RF
board.
2. Put the set into play mode by loading the disc.
3. Confirm that oscilloscope waveform is clear and check RF sig-
3. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
Note:
Clear RF signal waveform means that the shape “
◊
” can be clearly distin-
guished at the center of the waveform.
• TRACKING OFFSET CHECK
– RF BOARD (Conductor Side) –
Procedure:
1. Connect the oscilloscope to BP11 (TE) and TP (VC) on the
1. Connect the oscilloscope to BP11 (TE) and TP (VC) on the
RF board.
2. Put the set into play mode by loading the disc.
3. Press the . AMS > button, and check the traverse wave-
3. Press the . AMS > button, and check the traverse wave-
form*.
4. Confirm that the oscilloscope waveform is symmetrical on the
top and bottom in relation to 0 V dc, and check this level.
* Traverse waveform: This is the tracking error wave form appears
when crossing the track.
TP
(VC)
IC11
IC51
CNJ12
TP (RF)
oscilloscope
+
–
–
RF signal waveform
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 1.4
±
0.3 Vp-p
TP
(VC)
IC11
IC51
CNJ12
BP11
(TE)
oscilloscope
+
–
–
A
B
0 V
A=B
traverse waveform
(100 track jump waveform)
(100 track jump waveform)
VOLT/DIV : 500 mV
TIME/DIV : 2 ms
Center : 0 V
TIME/DIV : 2 ms
Center : 0 V
Traverse waveform
16
16
CDX-838
7-1.
BLOCK DIAGRAM – SERVO Section –
SECTION 7
DIAGRAMS
XROF
M
M
M
A
B
D
F
E
C
I-V AMP
DETECTOR
39
38
2
1
12
13
27
OUT+
OUT–
SLO
OUT–
OUT+
OUT+
OUT–
SPINDLE
MOTOR DRIVE
M101
(SPINDLE)
SLED
MOTOR DRIVE
26
M102
(SLED)
FOCUS
COIL DRIVE
TRACKING
COIL DRIVE
OUT+
OUT–
OUT–
19
24
4
10
IN
IN
IN
IN
SLP
FOCUS/TRACKING COIL DRIVE,
SPINDLE/SLED MOTOR DRIVE
IC51
16
14
SLED
AMP
LD
PD
LASER DIODE
OPTICAL PICK-UP
BLOCK
(KSS-521A)
2-AXIS
DEVICE
(FOCUS)
(TRACKING)
33
32
27
44
23
22
20
21
19
23
RF AMP,
FOCUS/TRACKING
SERVO
IC11 (1/2)
FOCUS OK
COMPARATOR
MIRR
AMP
DEFECT
AMP
FOCUS OK
AMP
IIL DATA REGISTER
40
38
FILTER
42
39
FILO
PCO
CLTV
FILI
DIGITAL PLL
ASYMMETRY
CORRECTION
CORRECTION
EFM
DEMODULATOR
DIGITAL
OUT
ERROR
CORRECTOR
16K
RAM
INTERNAL BUS
SUB-CODE
PROCESSOR
SERVO AUTO SEQUENCER
DIGITAL CLV
17
15
52
54
50
100
16
WDCK
8 7 9 10 12 11 75 76 77
61
26
28
14
13
1
7
4
5
4
5
CH.F
CH.R
CHUCKING
MOTOR DRIVE
CHUCKING MOTOR DRIVE
IC52
FIN
RIN
OUT1
OUT2
SW11
(CHUCKING END DETECT)
LOAD1
LOAD2
SW12
(SAVE END DETECT)
SW1
(LIMIT)
M103
(CHUCKING)
41
42
36
37
1
40
45
2
47
17
16
6
25
24
13
+
PD1
PD1 I-V AMP
RFO
RF
46
ASYI
47
ASYO
FOK
DATO
CLKO
XLTO
SEIN
CNIN
CNIN
C.OUT
FOK
SUBQ
SCLK
SENS
CD.DATA
CD.CLK
CD.XLT
SCOR
MON
MDP
MDS
29
LOCK
64
SQSO
SQCK
SENS
DATA
CLOCK
XLAT
SCOR
SBSO
EXCK
GFS
GTOP
WFCK
EMPH
C4M
XRST
RFI
FOK
DATA
CLK
SENS1
26
SENS2
C.OUT
XLT
LOCK
XRST
PD2 I-V AMP
PD2
TTL
IIL
FEO
TEO
PD
FEI
FEO
TAO
TEI
TTL
IIL
TTL
IIL
FOCUS
ERROR
AMP
RF
SUMMING
AMP
TRACKING
ERROR
AMP
TRACKING PHASE
COMPENSATION
FOCUS PHASE
COMPENSATION
AUTOMATIC
POWER CONTROL
Q11
I-V
AMP
LD
AMP
PD
AMP
FE BIAS
RV14
F
E
LD
89
XTAI
PCMD
71
D.OUT
BCKO
LRCK
63
C2PO
62
49
RFCK
RFCK
DATA
PCMD
BCK
LRCK
WDCK
A
XRST
RESET
ON : When completion of the disc
chucking operation.
ON : When the optical pick-up
is inner position.
SLED SERVO
IC11 (2/2)
05
DIGITAL SIGNAL PROCESSOR,
CLV SERVO
IC101
SYSTEM CONTROLLER
IC201 (1/3)
ON : When completion of the disc
chucking operation.
• SIGNAL PATH
(Page 17)
(Page 17)
(Page 17)
: CD PLAY (ANALOG OUT)
: CD PLAY (DIGITAL OUT)
27
FOCUS
GAIN
CPU INTERFACE
D/A
INTERFACE
CLOCK
GENERATOR
EDGE DETECT
IC403 (1/2)
70
74
72
58
1
2
7
IC403
(2/2)
GTOP
WFCK
C4M
XROF
SCLK
SBSO
C16M
22
SENS2
8
54
52
51
23
23
67
65
66
63
GFS 24
21
C
E
(Page 17)
(Page 17)
D
RFCK, GTOP, WFCK,
C4M, XROF,
DATA, PCMD, BCK,
LRCK, WDCK
(Page 17)
B
H
SCOR
(Page 17)
G
DATA, CLOCK
DATA
CLOCK
(Page 17)
F
LIM.SW 9
7
6
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