Sony HCD-VX777 Service Manual ▷ View online
17
HCD-VX777
FM Tuned Level Adjustment
Procedure:
1.
1.
Supply a 28 dB 98 MHz signal from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Adjust RV611 to the point (moment) when the TUNED
indicator will change from going off to going on.
indicator will change from going off to going on.
Adjustment Location: MAIN board
Null Adjustment
Procedure:
1.
1.
Supply a 60 dB 98 MHz signal from the ANTENNA terminal.
2.
Tune the set to 98 MHz.
3.
Measure voltage between pin 21 of IC 601. Adjust T11 ubtil
the voltage becomes 0 V.
the voltage becomes 0 V.
Adjustment Location: MAIN board
Adjustment Location
[MAIN BOARD] Component side
FM RF SSG
75
Ω
coaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 28 dB (at 75 W open)
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 28 dB (at 75 W open)
FM ANTENNA terminal
(TM1)
(TM1)
set
FM RF SSG
75
Ω
coaxial
Carrier frequency : 98 MHz
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 60 dB (at 75 W open)
Modulation : AUDIO 1 kHz, 75 kHz
deviation (100%)
Output level : 60 dB (at 75 W open)
FM ANTENNA terminal
(TM1)
(TM1)
set
CD SECTION
Note :
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use LUV-P01 (4-999-032-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M
3. Use an oscilloscope with more than 10M
Ω
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.
following checks.
S-Curve Check
Procedure :
1. Connect oscilloscope to TP (FEO).
2. Connect between TP (FEI) and TP (DVC ( 1.65 V) by lead
1. Connect oscilloscope to TP (FEO).
2. Connect between TP (FEI) and TP (DVC ( 1.65 V) by lead
wire.
3. Turn Power switch on.
4. Load a disc (LUV-P01) and actuate the focus search. (In
4. Load a disc (LUV-P01) and actuate the focus search. (In
consequence of open and close the disc tray, actuate the focus
search)
search)
5. Confirm that the oscilloscope waveform (S-curve) is
symmetrical between A and B. And confirm peak to peak level
within 2 ±0.5 Vp-p.
within 2 ±0.5 Vp-p.
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.
RF Level Check
Procedure :
1. Connect oscilloscope to TP (RFDC) and (RFAC).
2. Turned Power switch on.
3. Load a disc (LUV-P01) and playback.
4. Confirm that oscilloscope waveform is clear and check RF signal
1. Connect oscilloscope to TP (RFDC) and (RFAC).
2. Turned Power switch on.
3. Load a disc (LUV-P01) and playback.
4. Confirm that oscilloscope waveform is clear and check RF signal
level is correct or not.
BD board
Oscilloscope
TP(FEO)
TP(DVC)
TP(DVC)
symmetry
S-curve waveform
within 2
±
0.5Vp-p
A
B
TP(RF)
TP(DVC)
TP(DVC)
BD board
oscilloscope
RV354
CN303
CN301
CN304
RV304
RV301
RV352
RV302
RV302
RV353
RV303
RV351
RV11
T11
FM TUNED LEVEL
NULL
1
3
18
HCD-VX777
Note:
Clear RF signal waveform means that the shape “
◊” can be
clearly distinguished at the center of the waveform.
RF signal waveform
E-F Balance (1 Track jump) Check
Procedure:
1.
1.
Connect oscilloscope to TP (TEO) and TP (DVC) board.
2.
Turned Power switch on.
3.
Load a disc (LUV-P01) and playback the number nine track.
4.
Press the bB button. (Becomes the 1track jump mode.)
5.
Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
waveform.
1 track jump waveform
6.
Adjust RV101 so that A (DC voltage) becomes 0.
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
level : 0.65
±
0.15Vp-p (RFDC)
1.1
±
0.4Vp-p (RFAC)
oscilloscope
BD board
TP (TEO)
TP (DVC)
TP (DVC)
+
–
–
DVC
Center of
waveform
waveform
B
Symmetry
A (DC voltage)
level=1.0
±
0.5Vp-p
Checking Location:
[BD BOARD]
IC103
IC101
TP
(RFDC)
(RFDC)
TP
(CE)
(CE)
TP
(RFAC)
(RFAC)
TP
(XPCK)
(XPCK)
VIDEO SECTION
Frequency adjustment
1.
Connect the frequency counter to check point of the VIDEO
board.
board.
2.
Adjust CT503 of the VIDEO board so that the frequency
counter read 27MHz ± 80Hz at STOP condition.
counter read 27MHz ± 80Hz at STOP condition.
[ VIDEO BOARD ] – SIDE B –
Adjustment Location :
[ VIDEO BOARD ] – SIDE A –
frequency counter
VIDEO board
(27 MHz)
(27 MHz)
+
–
–
SL501
IC502
SL502
SL503
TEST
MODE
SL501 SL502
CT503
SL503
TEST MODE
VIDEO
FREQUENCY
(27MHz)
(GND)
IC507
IC505
19
19
HCD-VX777
6-1. CIRCUIT BOARD LOCATION
POWER board
MAIN board
SENSOR board
SUB TRANS board
SW board
MAIN TRANS board
CD SW board
PAD SWITCH board
PANEL board
DRIVER board
VIDEO board
LEAF SW board
HEAD (B) board
HEAD (A) board
BD board
MOTOR board
SENSOR board
SECTION 6
DIAGRAMS
Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted. pF: µµF
• All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
and tantalums.
• All resistors are in
Ω
and
1
/
4
W or less unless otherwise
specified.
•
f
: internal component.
•
C
: panel designation.
Note on Printed Wiring Boards:
• X
: parts extracted from the component side.
•
: Pattern from the side which enables seeing.
• Indication of transistor.
Note:
The components identified by mark
The components identified by mark
0
or dotted line with
mark
0
are critical for safety.
Replace only with part number specified.
•
A
: B+ Line.
•
B
: B– Line.
•
H
: adjustment for repair.
• Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
• Voltages are taken with a VOM (Input impedance 10 M
Ω
).
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Waveforms are taken with a oscilloscope.
Voltage variations may be noted due to normal produc-
tion tolerances.
tion tolerances.
• Circled numbers refer to waveforms.
• Signal path.
F
: FM
f
: AM
E
: PB (DECK A)
d
: PB (DECK B)
G
: REC (DECK B)
J
: CD
c
: digital out
m
: CHROMA
n
: Y
: VIDEO
: VIDEO
• Abbreviation
EA
: Saudi Arabia model
IA
: Indonesian model
SP
: Singapore model
TH
: Thai model
THIS NOTE IS COMMON FOR PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS.
(In addition to this, the necessary note is printed in each block.)
(In addition to this, the necessary note is printed in each block.)
B
These are omitted.
C
E
Q
C
B
These are omitted.
E
Q
HCD-VX777
20
20
• WAVEFORMS
1
IC101
us
(XTAO)
CD PLAY MODE
4.0Vp-p
16.9344MHz
1.2Vp-p
2
IC101
t;
(RFAC)
CD PLAY MODE
3
IC101
ra
(TE)
CD PLAY MODE
4
IC101
el
(FE)
CD PLAY MODE
400nsec/div
approx 150mVp-p
approx 200mVp-p
1
IC501
qa
(XC-OUT)
STOP MODE
3.0Vp-p
32.768kHz
2.8Vp-p
2
IC501
qd
(X-OUT)
STOP MODE
3
T301
4
TAPE B REC MODE
16MHz
120Vp-p
80.7kHz
1
IC601
is
(XOUT)
STOP MODE
3.0Vp-p
4MHz
– BD BOARD –
– MAIN BOARD –
– PANEL BOARD –
1
IC502
qd
XOUT
2
IC505
ug
COUT
3
IC505
yl
YOUT
4
IC304
9
COUT
5
IC304
qg
YOUT
7
IC509
ql
LRCK
8
IC509
qj
BCK
9
IC504
8
384FS
q;
IC504
6
27M
4Vp-p
10MHz
H
0.6Vp-p
H
1.5Vp-p
1Vp-p
H
2Vp-p
H
27MHz
0.7Vp-p
5.0Vp-p
44.1kHz
5.0Vp-p
2.11MHz
5.0Vp-p
33.8MHz
4.0Vp-p
27MHz
6
– VIDEO BOARD –
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