Sony Vx8 Owners Manual

							Ð 11 Ð
AMS Test  Mode
¥ This mode is used for checking the AMS operations of the tape deck.
JIG
7-819-039-12 Alignment  tape, AMS-110A
Procedure:
1. Press the  1/u  button to turn the unit ON.
2. Set the tape (AMS-110A).
3. Press the three buttons  p  ,  ENTER/NEXT  , and  DISC 3  button simultaneously.
4. ÒTEST MODEÓ is displayed on the fluorescent display tube.
5. Press the  FUNCTION  button and switch the function to the deck with the tape (AMS-110A).
6. Press the  CD SYNC  button. ÒAMS CHECKÓ is displayed on the fluorescent display tube and the tape is rewound.
7. AMS starts in the normal direction. If the AMS count is 2 at shut down, proceed to step 8.
ÒNGÓ is displayed at other times, and the deck stops.
8. AMS starts in the opposite direction. If the AMS count is 2 at shut down again, ÒOKÓ is displayed.
ÒNGÓ is displayed at other times.
Note:The  p  button of CD section will become effective and the aging of CD section will stop sometime, if the buttons described in step 3
are not pressed simultaneously. In that case, press  ^  button and operate the CD section. 
						

							Ð 12 Ð
SECTION  5
TEST MODE
VIDEO CD COLOR-BARS MODE
On this mode, the data of the color-bars signal as a picture signal and the 1kHz sine wave signal as a sound signal are output by the
mechanism control microcomputer (IC502) for video CD signal check. When measurement of the voltage and waveform on the VIDEO
board, perform it in this mode.
For refernce, the color-bars signal can be observed at J302 (VIDEO OUT) and the sound signal can be observed at J101 (VIDEO/MD
(AUDIO) OUT) using an oscilloscope.
1. Connect the lead wire to both ends of the land of SL503 of the VIDEO board.
2. Turn the power on. Press  FUNCTION  button to select CD.
3. After 2 or 3 seconds later, connect the lead wire.
4. After measuring, remove the lead wire connected.
[VIDEO BOARD] (SIDE A)
[VIDEO BOARD] (SIDE B)
SL501 D502
SL502
IC507 IC505
CT503 SL503
TEST MODE
VIDEO
FREQUENCY
SL501IC502
SL502 SL503
TEST
MODE 
						

							Ð 13 Ð
Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads pinch rollers
erase head rubber belts
capstan idlers
2. Demagnetize the record/playback head with a head demagne-
tizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
Torque Measurement
31 to 71 g ¥ cm
(0.43 Ð 0.98 oz ¥ inch)
2 to 6 g ¥ cm
(0.02 Ð 0.08 oz ¥ inch)
31 to 71 g ¥ cm
(0.43 Ð 0.98 oz ¥ inch)
2 to 6 g ¥ cm
(0.02 Ð 0.08 oz ¥ inch)
71 to 143 g ¥ cm
(0.98 Ð 1.99 oz ¥ inch)
100 g or more
(3.53 oz or more)
100 g or more
(3.53 oz or more)
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
Procedure:
1. Mode : Playback
SignalUsed forTape
SECTION 6
MECHANICAL ADJUSTMENTS
Mode
FWDTorque meter
CQ-102CMeter reading
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tensionCQ-102C
CQ-102RC
CQ-102RC
CQ-201B
CQ-403A
CQ-403R
SECTION 7
ELECTRICAL ADJUSTMENTS
DECK SECTION 0 dB=0.775V
1. Demagnetize the record/playback head with a head damagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjusted.
4. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in this
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit adjust-
ment.)
6. The adjustments should be performed for both L-CH and R-CH.
7. Switches and controls should be set as follows unless otherwise
specified.
P-4-A100
WS-48B
P-4-L30010 kHz, Ð10 dB
3 kHz, 0 dB
315 Hz, 0 dBAzimuth Adjustment
Tape Speed Adjustment
Level Adjustment
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw 
so
that outputs match within 1 dB of peak.
test tape
P-4-A100
(10kHz, –10dB)
MD OUT
level meter
set
+
–
L-CH
peak
R-CH
peak
screw
positionoutput
levelwithin
1 dB
L-CH
peakR-CH
peakscrew
position within 1dB 
						

							Ð 14 Ð
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
Adjustment Location:Playback Head (Deck A)
Record/Playback/Erase Head (Deck B) 3. Mode: PlaybackTape Speed Adjustment (Deck A)
Note:Set the test mode using the following method and begin tape
speed adjustment.
In the test mode, the speed will switch to double speed or
normal speed each time the  HI DUB  button is pressed.
Procedure:
With the power turned ON, press the p  button,  ENTER/NEXT
button, and  DISC 3  button simultaneously.
(The ÒCD TYPE INDICATORÓ on the fluorescent display tube will
blink while in the test mode.)
To exit the test mode, press the  1/u  button.
1. Insert the WS-48B into deck B.
2. Press the  (  button of deck B.
3. Press the  HI DUB  button and play the tape at double speed.
4. Adjust RV1001 of the LEAF SW board so that the reading of
the frequency counter becomes 6000 ± 180 Hz.
5. Press the  HI DUB  button and play the tape at normal speed.
6. Adjust RV1002 of the LEAF SW board so that the reading of
the frequency counter becomes 3000 ± 90 Hz.
Adjustment Location: LEAF SW board
Sample Value of Wow and flutter
W.RMS (JIS) less than 0.3%
(test tape: WS-48B)
Playback Level Adjustment (Deck A,  Deck B)
Procedure:
Mode: Playback
Deck A is RV311 (L-CH) and RV411 (R-CH), deck B is RV301
(L-CH) and RV401 (R-CH)
so that adjustment within the following adjustment level.
Adjustment level:
CN301 playback level: 301.5 to 338.3 mV (Ð8.2 to Ð7.2 dB)
level difference between the channels: within ± 0.5 dB
Adjustment Location: AUDIO  board
Adjustment Location
[LEAF SW BOARD]
test tape
P-4-A100
(10kHz, –10dB)
oscilloscope
set
Waveform of oscilloscope
in phase 45
¡90¡135¡180¡
goodwrong MD OUT
Reverse Foward
test tape 
P-4-L300
(315Hz, 0dB)level meter
set
MD OUT
RV1002RV1001RV1002(Normal Speed
)RV1001(High Speed) 
						

							Ð 15 Ð
Record Bias Adjustment  (Deck B)
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjust-
ment, when the tape is rewound after recording, the ÒREC memory
modeÓ which rewinds only the recorded portion and playback is
set.
This ÒREC memory modeÓ is convenient for performing this ad-
justment. During recording, the input signal FUNCTION will auto-
matically switch to VIDEO.
(After recording, press the  Ð 0  button without stopping will
return to the position where recording was started.)
1. Press  FUNCTION  button to select VIDEO. (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
5. Confirm playback the signal recorded in step 2 become adjust-
ment 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  boardRecord Level Adjustment  (Deck B)
Procedure:
INTRODUCTION
When set to the test mode performed in Tape Speed Adjust-
ment, when the tape is rewound after recording, the ÒREC memory
modeÓ which rewinds only the recorded portion and playback is
set.
This ÒREC memory modeÓ is convenient for performing this
adjustment. During recording, the input signal FUNCTION will au-
tomatically switch to VIDEO.
(After recording, press the  Ð 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 adjust-
ment 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 (Ð24.3 to Ð23.3 dB)
Adjustment Location: MAIN board
Adjustment Location:
[AUDIO BOARD] (Conductor Side)
4. Mode: Playback
[MAIN BOARD] (Conductor Side)
recorded
positionlevel meter
set
MD OUT
AF OSCVIDEO (AUDIO) IN
1) 315 Hz
2) 10 kHz
blank tape
CS-123
set
attenuator600 W
} 50 mV (–23.8 dB)
AF OSCVIDEO (AUDIO) IN
315Hz 50 mV (–23.8 dB)
blank tape
CS-123
set
attenuator600 W
recorded
positionlevel meter
set
MD OUT
RV441 RV341
RV301(Lch),RV401(Rch)
Playback Level (Deck B) RV301 RV401
RV341(Lch),RV441(Rch)
Record BiasRV311(Lch),RV411(Rch)
Playback Level (Deck A)
RV311
RV411
IC301
Record Level (L CH)
RV301
CN303
RV351
Record Level (R CH) 5643
42
29
28
15
14 1 
						

							Ð 16 Ð
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 10MW 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 bright-
ness 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 sig-
nal 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/DOLBY NR  button. (The tracking
servo and the sledding servo are turned OFF.)
6. Check the level B of the oscilliscopes 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-pA (DC voltage) Center of the waveform
B
7. Press the  PLAY MODE/DOLBY NR  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
0VC (DC 
voltage)
Tracking servo
Sled servo
        OFFTracking servo
Sled servo
        ON
symmetry
A
BWithin 4.0 
± 1.0 Vp-p
Note:Clear RF signal waveform means that the shape ÒàÓ 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 
						

							Ð 17 Ð
VIDEO SECTION
Frequency adjustment
1. Connect the frequency counter to check point of the VIDEO
board.
2. Adjust CT503 of the VIDEO board so that the frequency counter
read 27MHz ± 80Hz at STOP condition.
[ VIDEO BOARD ] Ð SIDE B Ð Adjustment Location :
[ VIDEO BOARD ] Ð SIDE A Ðfrequency counter
VIDEO board
(29 MHz)+
–
SL501IC502IC506 (27MHz)
(GND)
SL502 SL503
TEST
MODE
SL501 D502
SL502
CT503 SL503TEST MODE
VIDEO
FREQUENCY
(27MHz)
(GND)IC507 IC505
Adjustment Location :
[ BD BOARD ] Ñ SIDE B Ñ
TP
(VC)TP
(RF)
TP
(TE)
TP
(IOP)TP 
(FE)
TP
(AGCCON) 
						

							Ð 18 Ð
SECTION  8
DIAGRAMS
8-1. CIRCUIT BOARDS LOCATION
ENCAPSULATED COMPONENT/TUNER
unit is supplied as the assembled block.
MAIN board PANEL board
CD SW board
SURROUND board
ENCAPSULATED COMPONENT
(EXCEPT THAI)
TUNER unit
(THAI)
TRANS board
VIDEO board
SENSOR boardCONNECTOR board
BD board
MOTOR (SLIDE) board MOTOR (TURN) board
AUDIO board LEAF SW board 
						

							HCD-VX8/VX8J
Ð 19 ÐÐ 20 Ð
8-2. BLOCK DIAGRAMS
Ð CD SECTION Ð
E
FA
BC
D
DRIVE
Q101LDRF EQ 
AMP
SUMMING
AMPRFERROR
AMP FOCUSERROR
AMP TRACKING
APC LD 
AMP
VC 
BUFFER
VC 
REF  RF AMPIC103DIGITAL SERVO
DIGITAL SIGNAL PRCESSORIC101IC381
LASER
DIODE DETECTOR OPTICAL PICK-UP BLOCK
(D/Q-Np)
A
C
D
B
E
F
LD
POWERPDLD
PDLDA
C
D
B
E
FTE  FE RFD 
RFI
ASYMMETRY 
CORRECTION
AUTO
SEQUENCERSERVO
INTEG- 
RATOR
DIGITAL 
PLL
EFM 
DEMODULATOR
 
REGISTER
SUB CODE
PROCESSOR
ERROR
CORRECTOR
DATA BUS
32K 
RAM
D/A
INTERFACE
DIGITAL CD DIGITAL 
OUT 
OPTICAL 
OUT
DOUT 
SERVO 
INTERFACE
DIGITAL
CLV
LD ON 
OP AMP
ANALOG SWA/D
CONVERTER
PWM
GENERATORTRACKING
PWM
GENERATORFOCUS
PWM
GENERATORSLEDPWM
GENERATOR
VC 
TRACKING 
SERVO
FOCUS 
SERVO
SLED 
SERVOSERVO DSP
TFDR
TRDR
FFDR
FRDR
SFDR
SRDR
MDPDETECTOR
MIRR
DFCT
FOK
D OUT
PCM-D
S STOP RFDC
FE
TE
CE
VC
SECPU 
INTERFACESENS
DATA
XLAT
CLOK CLOCK 
GENERATORXTAI
XTSL
MM
TRACKING
COIL
FOCUS
COIL
SLED
MOTORM102
SPINDLE
MOTORM101T+
T
F+
F
SD+
SD
SP+
SPFOCUS/TRACKING COIL DRIVE
SPINDLE/SLED MOTOR DRIVEIC102
VC TFDR
TRDR
FFDR
FRDR
SFDR
SRDR
XRST
MUTE
09
S101 
LIMIT SW SQCK
A+5V  IC104
XRSTADATA
BCLK
LRCK
MCK
SENS CTRL1
DATA
SCLK
SCLK XLT
CLK
SCOR
SQSOSCOR
SUBQ
SQCK
LPH
XRST
LD ON LRCK BCLK
C2PO
MUTE MUTE C2PO
D+5V MD2
RF AC
ASYI
ASYO
CONTROL SIGNAL
BLOCK
SERVO 
BLOCK
VCC
VC
VIDEO
SECTION
• SIGNAL PATH
            : CD
            : Digital out
            : VIDEO
(Page 21)MAIN
SECTION(Page 25
M
TABLE
SENSOR
IC702
T. SENSOPEN S801
OPEN/CLOSE
DET
OUT1IN1
IN2
OUT2
M
M701
TURN
MOTOR
TBL.L
TBL.R TURN
MOTOR DRIVER
IC701
DISC
SENSOR
IC703ROTARY
ENCODER
S811
Q701DISC SENS
ENC 1
ENC 2
ENC 3
M801
SLIDE
MOTOROUT2
OUT1RIN
FIN SLIDE
MOTOR DRIVER
IC801
LOAD IN
LOAD OUT
A
C
(XTAL 33.8MHz)
42
5786111034
2324272520
22
21
1213171416
50484943384139404232313433302925
646367661465713769156547776826
88
82
88
8888
1
1211141317181516
3265
INTEG- 
RATOR 
						

							HCD-VX8/VX8JÐ VIDEO SECTION Ð
Ð 21 ÐÐ 22 Ð
SYSTEM
SELECTS501
651513
09
29
     I
2C.CLK
30
     I
2C.DATA I
2C.CLK   I2C.DATA
 I to U
 U to I
 TXD
 RXD
72
     U to I      DSENS      XRESET      TEST LED     NT/PAL     XOUT
     +5V
     D502      A7      DF LATCH      SHARPNESS
     XIN
24
45
BUS
DSP DATA
DSP LATCH
SENSE CLKDSP CLK
SENSE
DSP MUTE
CTRL1(L:DOUBLE)
CTRL2
LDON
SCOR
SUBQ DATA
2234
X501
NTSC
AUTO
PAL   10MHz
X503
27MHz
1920X401
8MHz MECHA. CONTROL
IC502
INTERFACE
IC402LEVEL SHIFT
IC504 LEVEL SHIFT
IC501D-RAM
IC507ROM
IC506
AMP
IC101 OUTPUT AMP
IC401
VIDEO/CD DECODER
IC505
DIGITAL FILTER & D/A CONVERTER
IC509
DATA1O
DATA1I
CLK1
CL680 INT
CL680 HSEL
CL680 HRDY
680 RESET DATA0
DATAI
CLK1
INT
HSEL
HRDY
RESET ADATA
BCLK
LRCK
C2P0
DATA
XLT
CLK
SENS
SCLK
MUTE
CTRL1
LDON
SCOR
SUBQ
SQCK
XRST
MCK
A CD
SECTION
(Page 20)
11121013
9
• R CH: Same as L ch
• SIGNAL PATH
            : CD
            : CHROMA
            :Y
            : VIDEO
SUBQ CLK
DEVICE RESET
23
1914
     RESET
     XIN
     XOUT18
937312 P.ON38 3
4
5
1
2
10
11
27
28
18
37 36
77 20
21 33 32
31
69
HD-OUT
6
CD-C2P0 CD-LRCKCD-BCK
HRDYHD-IN
HCK
HINT
HSEL
RESET
PGIO2/VSYNC/CSYNC INVERTER
Q502CD-DATAMWE WE
RAS
UCAS
LCAS
A0
A8
DQ1
DQ16 RASO
CAS
MCE MD0
I   
MD15
MA0
I   
MA10
      C-OUT       Y-OUT
75      DA-DATA      DA-BCK111      VCK-IN106      DA-XCLK86 110      DA-LRCK108 112
119
117
113
114
121
93603
5 4
13142829
3842
40
10
8 4
13
5 1
1
3
8
126
11
1 37
5
1
3
1917
DATA0
CLK187
10
21 20
4
11
18
MODEPLM D/A
CONV
CLOCK
DIVIDER9
241
16 - 19   22 - 26
2 - 10    31 - 39
O0
O7
A11
A17
A0
A10
CE
13 - 15   17 - 21
25  4  28  29  3  2  14  10   
12 - 5  27  26  23     
58 - 44     
10 - 29      
2237
MUTE
Q454
BUFFER
Q301
MUTE
Q453
MIX AMP
Q308,310
BUFFER
Q303,304TRAP
Q302,306,307
13
2 4
14
VIDEO OUTJ302
J301
VIDEO
FREQUENCYCT503
–5V/IIC DATAL - CH
R-CH
P. ON/IIC. CLKXRST
27MHz
384FS
768FS
S VIDEO 
   OUT
DATAI
DATAO
CLK1
HRDY
INT
HSEL
RST
CLK1, DATA0
(XTAL 33.8MHz)27MHz
RSTB
3.3V REG
Q531
+3.3V D5V
CMAIN
SECTION
(Page 25)
EMAIN
SECTION
(Page 26)