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Model
HCD-VR90AV
Pages
96
Size
10.29 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio
File
hcd-vr90av.pdf
Date

Sony HCD-VR90AV Service Manual ▷ View online

17
Record Bias Adjustment  (Deck B)
Procedure:
INTRODUCTION
When set to the test mode performed in 
Tape Speed Adjustment
,
when the tape is rewound after recording, the “REC memory mode”
which rewinds only the recorded portion and playback is set.
This “REC memory mode” is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO 1.
(After recording, press the  
0  button without stopping will return
to the position where recording was started.)
1.
Press  FUNCTION  button to select VIDEO 1. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B, press the  
r REC  button, and then
press the  
·  button to start recording.
3.
Mode: Record
4.
Mode: Playback
adjustment level as follows.
If these levels do not adjustment level, adjust the RV341 (L-
CH) and RV441 (R-CH) on the AUDIO board to repeat steps 3
and 4.
Adjustment level: The playback output of 10 kHz level difference
against 315 Hz reference should be ± 1.0 dB.
Adjustment Location: AUDIO board
Record Level Adjustment  (Deck B)
Procedure:
INTRODUCTION
When set to the test mode performed in 
Tape Speed Adjustment
,
when the tape is rewound after recording, the “REC memory mode”
which rewinds only the recorded portion and playback is set.
This “REC memory mode” is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to VIDEO 1.
(After recording, press the  
0  button without stopping will return
to the position where recording was started.)
1.
Press  FUNCTION  button to select VIDEO 1. (This step is not
necessary if the above test mode has already been set.)
2. Insert a tape into deck B, press the  
r REC  button, and then
press the  
·  button to start recording.
3.
Mode: Record
4.
Mode: Playback
5.
Confirm playback the signal recorded in step 2 become
adjustment level as follows.
If these levels do not adjustment level, adjust the RV301 (L-
CH) and RV351 (R-CH) on the MAIN board to repeat steps 3
and 4.
Adjustment level:
CN403 playback level: 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location: MAIN board
Adjustment Location:
[AUDIO BOARD] (Conductor Side)
5.
Confirm playback the signal recorded in step 2 become
[MAIN BOARD] (Conductor Side)
recorded
position
level meter
set
MD OUT
AF OSC
VIDEO 1 (AUDIO) IN
1) 315 Hz
2) 10 kHz
blank tape
CS-123
set
attenuator
600 
} 50 mV (–23.8 dB)
AF OSC
VIDEO 1 (AUDIO) IN
315Hz 50 mV (–23.8 dB)
blank tape
CS-123
set
attenuator
600 
recorded
position
level meter
set
MD OUT
Record Level (Lch)
RV301
RV351
Record Level (Rch)
IC301 56
43 42
29
28
15
14
1
1
3
RV441 RV341
RV301(Lch),RV401(Rch)
Playback Level (Deck B)
RV301 RV401
RV341(Lch),RV441(Rch)
Record Bias
RV311(Lch),RV411(Rch)
Playback Level (Deck A)
RV311
RV411
18
  CD SECTION
Note:
1.
CD Block is basically constructed to operate without
adjustment. Therefore, check each item in order given.
2.
Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3.
Use an oscilloscope with more than 10M
 impedance.
4.
Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
S Curve Check
Adjustment Location: BD board
Procedure :
1.
Connect the oscilloscope to test points TP (FE) and TP (VC).
2.
Connect TP (FEI) and GND, and TP (AGCCON) and GND of
the BD board with lead wires.
3.
Press the  
1/u  button to turn the set ON.
4.
With the disc (YEDS-18) loaded, press the  
^  button and
perform focus search. (Focus search will be performed in the
same way even while the disc table is pushed in and out.)
5.
Check the symmetry and peak to peak level of the oscilloscope
waveform (S curve) at this time.
S-curve waveform
6.
After check, remove the lead wire connected in step 2.
Note:
 • Try to measure several times to make sure than the ratio
of A : B or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.
Adjustment Location: BD board
RF Level Check
Procedure :
1.
Connect oscilloscope to test point TP (RF) and TP (VC) on
BD board.
2.
Connect TP (AGCCON) and GND of the BD board with lead
wires.
3.
Press the  
1/u  button to turn the set ON.
4.
Put disc (YEDS-18) in and playback 5track.
5.
Confirm that oscilloscope waveform is clear and check RF
signal level is correct or not.
6.
After check, remove the lead wire connected in step 2.
oscilloscope
BD board
TP (FE)
TP (VC)
+
oscilloscope
BD board
TP (RF)
TP (VC)
+
E-F Balance (Traverse) Check
oscilloscope
BD board
TP (TE)
TP (VC)
+
Adjustment Location: BD board
Procedure :
1.
Connect oscilloscpe to test point TP (TE) on BD board.
2.
Short-circuit SL502 of the video board to GND.
3.
Turned Power switch on. Press  FUNCTION  button to select
CD.
4.
Put disc (YEDS-18) in to play the number five track.
5.
Press the  PLAY MODE  button. (The tracking servo and the
sledding servo are turned OFF.)
6.
Check the level B of the oscilliscope's waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than ± 22%
Traverse waveform
0V
level : 1.3 
±
 0.6 Vp-p
A (DC voltage)
Center of the waveform
B
7.
Press the  PLAY MODE  button. (The tracking servo and
sledding servo are turned ON.) Confirm the C (DC voltage) is
almost equal to the A (DC voltage) is step 7.
Traverse waveform
0V
C (DC 
voltage)
Tracking servo
Sled servo
        OFF
Tracking servo
Sled servo
        ON
symmetry
A
B
Within 4.0 
±
 1.0 Vp-p
Note:
Clear RF signal waveform means that the shape “
” can be
clearly distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.75 
±
 0.25 Vp-p
8.
Desolder the short-land (SL502) short-circuited at step 2.
Adjustment Location: BD board
19
19
6-1. CIRCUIT BOARDS LOCATION
SECTION 6
DIAGRAMS
   VIDEO SECTION
Frequency adjustment
1.
Connect the frequency counter to check point TP508 (27MHz)
of the VIDEO board.
2.
Adjust CT503 of the VIDEO board so that the frequency counter
read 27MHz ± 80Hz at STOP condition.
[ VIDEO BOARD ] – SIDE B –
Adjustment Location :
[ VIDEO BOARD ] – SIDE A –
frequency counter
VIDEO board
(27 MHz)
+
SL501
D502
SL502
CT503
TP508
SL503
TEST MODE
VIDEO
FREQUENCY
(27MHz)
(GND)
IC507
IC505
Adjustment Location :
[ BD BOARD ] — SIDE B —
TP
(VC)
TP
(RF)
TP
(TE)
TP
(IOP)
TP 
(FE)
TP
(AGCCON)
TUNER UNIT
SURROUND AMP board
JACK board
VIDEO  board
TC-B board
TC-A board
FL board
PANEL VR board
FRONT INPUT board
TRANS board
MAIN board
PA board
CD-L board
CD-R board
LED (PANEL) board
DOOR SW board
BD board
LED (CD) board
CD MOTOR board
TABLE SENSOR board
AUDIO board
LEAF SW board
SL501
IC502
IC506
(27MHz)
(GND)
SL502
SL503
TEST
MODE
TP508
HCD-VR90AV
20
20
6-2. BLOCK DIAGRAMS
BD SECTION
E
F
A
B
C
D
DRIVE
Q101
LD
RF EQ
AMP
RF
SUMMING
AMP
FOCUS
ERROR
AMP
TRACKING
ERROR
AMP
APC LD
AMP 
VC
BUFFER
VC 
REF 
RF AMP
IC103
DIGITAL SERVO
DIGITAL SIGNAL PRCESSOR
IC101
IC781
LASER
DIODE
DETECTOR
OPTICAL PICK-UP BLOCK
(KSS-213D/Q-NP)
A
C
D
B
E
F
LD
POWER
PD
LD
PD
LD
A
C
D
B
E
F
TE 
FE
RFO
RFI
ASYMMETRY
CORRECTION
SERVO
AUTO
SEQUENCER
INTEG-
RATOR
DIGITAL
PLL
EFM
DEMODULATOR
REGISTER
SUB CODE
PROCESSOR
ERROR
CORRECTOR
DATA BUS
32K
RAM
D/A
INTERFACE
CD DIGITAL
OUT
OPTICAL 
DIGITAL
OUT
DOUT 
SERVO
INTERFACE
DIGITAL
CLV
LD ON 
OP AMP
ANALOG SW
A/D
CONVERTER
TRACKING
PWM
GENERATOR
FOCUS
PWM
GENERATOR
SLED
PWM
GENERATOR
PWM
GENERATOR
VC 
TRACKING
SERVO
FOCUS
SERVO
SLED
SERVO
SERVO DSP
TFDR
TRDR
FFDR
FRDR
SFDR
SRDR
MDP
DETECTOR
MIRR
DFCT
FOK
D OUT
PCM-D
S STOP
RFDC
FE
TE
CE
VC
SE
CPU
INTERFACE
SENS
DATA
XLAT
CLOK
CLOCK
GENERATOR
XTAI
XTSL
M
M
TRACKING
COIL
FOCUS
COIL
M102
SLED
MOTOR
M101
SPINDLE
MOTOR
T+
T–
F+
F–
SD+
SD–
SP+
SP–
FOCUS/TRACKING COIL DRIVE
SPINDLE/SLED MOTOR DRIVE
IC102
VC
TFDR
TRDR
FFDR
FRDR
SFDR
SRDR
XRST
MUTE
16
S101 
LIMIT SW
SQCK
A+5V 
IC104
XRST
ADATA
BCLK
LRCK
MCK
SENS
CTRL1
DATA
SCLK
SCLK
XLT
CLK
SCOR
SQSO
SCOR
SUBQ
SQCK
CTRL2
XRST
LD ON
LRCK
BCLK
C2PO
MUTE
MUTE
C2PO
RF AC
ASYI
ASYO
CONTROL
SIGNAL
BLOCK
SERVO
BLOCK
VCC
VC
: CD VIDEO
VIDEO
SECTION
(Page 21)
A
(XTAL 33.8MHz)
4
2
5
7
8
6
11
10
3
4
23
24
27
25
20
22
21
12
13
17
14
16
50
48
49
43
38
41
39
40
42
32
31
34
33
30
29
25
64
67
66
14
65
71
3
7
69
15
6
5
4
77
76
8
26
82
1
12
11
14
13
17
18
15
16
3
2
6
5
INTEG-
RATOR
• SIGNAL PATH
: CD AUDIO
: Digital out
LPH
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