Sony SLV-7700KML Service Manual ▷ View online
7-3
2-3. POWER SUPPLY CHECK
2-3-1. Output Voltage Check (PS-418 Board)
Mode
E-E
Measuring
Digital voltmeter
instrument
SW 5V check
Measurement
CN101 pin1
point
Specified
5.3 ± 0.3 Vdc
value
D 6V check
Measurement
CN101 pin5, CN103 pin7
point
Specified
5.9 ± 0.3 Vdc
value
+ F check
Measurement
CN101 between pin6 to 8
point
Specified
4.6 ± 0.7 Vdc
value
DC –30V check
Measurement
CN101 pin7
point
Specified
– 30 ± 3.0 Vdc
value
PS 13V check
Measurement
CN102 pin1, 2
point
Specified
13.2 ± 1.0 Vdc
value
MTR 12V check
Measurement
CN102 pin3, 4
point
Specified
12 ± 1.0 Vdc
value
SW 12V check
Measurement
CN102 pin8, CN103 pin1
point
Specified
12 ± 0.5 Vdc
value
AU –13V check
Measurement
CN102 pin9
point
Specified
– 13 ± 0.5 Vdc
value
SW –13V check
Measurement
CN103 pin4
point
Specified
– 13 ± 0.5 Vdc
value
MTR 10V check
Measurement
CN103 pin9
point
Specified
10 ± 1.0 Vdc
value
[Check Method]
1)
1)
Check that each voltage satisfied the specified value.
Note :
AC input voltage = 240 ± 5 Vac
2-4. VIDEO-CD SYSTEM ADJUSTMENTS
• CD Block is basically to operate without adjustment.
Therefore, check each item in order given.
• Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
• Use an oscilloscope with more than 10M
• Use an oscilloscope with more than 10M
Ω
impedance.
• Clean the object lens by an applicator with neutral detergent when
the signal level is low than specified value with the following
checks.
checks.
[Adjustment Sequence]
1)
1)
S-Curve check
2)
RF level check
3)
E-F Balance (Traverse) check
4)
RF PLL Free-run Frequency check
5)
Clock Adjustment
2-4-1. S-Curve Check (BD-21 Board)
Signal
Reference disc
Measurement
+ : TP FE
point
– : TP VC
Measuring
Oscilloscope
instrument
Specified
S-curve is symmetrical between A and B.
value
[Check Method]
1)
1)
Connect oscilloscope to test point TP (FE) on BD-21 board.
2)
Connect between test point TP (FEI) and TP (VC) by lead wire.
3)
Turned Power switch on.
4)
Put disc (YEDS-18) in and turned Power switch on again and
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
5)
Check the oscilloscope waveform (S-curve) is symmetrical
between A and B.
And confirm peak to peak level within 3 ± 1 Vp-p.
between A and B.
And confirm peak to peak level within 3 ± 1 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
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.
Fig. 7-2-6.
symmetry
within 3
±
1 Vp-p
A
B
S-curve waveform
7-4
2-4-2. RF Level Check (BD-21 Board)
Signal
Reference disc
Measurement
+ : TP RF
point
– : TP VC
Measuring
Oscilloscope
instrument
Specified
Confirm that oscilloscope waveform is clear
value
and check RF signal level is correct or not.
[Check Method]
1)
1)
Connect oscilloscope to test point TP (RF) on BD-21 board.
2)
Turned Power switch on.
3)
Put disc (YEDS-18) in to play the number five track.
4)
Confirm that oscilloscope waveform is clear and check RF
signal level is correct or not.
signal level is correct or not.
2-4-3. E-F Balance (Traverse) Check (BD-21 Board)
Signal
Reference disc
Measurement
+ : TP TE
point
– : TP VC
Measuring
Oscilloscope
instrument
Specified
A
×
100=less than ± 20%
value
B
[Check Method]
1)
1)
Connect oscilloscope to test point (TE) on BD-21 board.
2)
Turned Power switch on.
3)
Connect the SOL301 and SOL302 on the CD-169 board with
solder.
solder.
4)
Put disc (YEDS-18) in to play the number five track.
5)
Press the PLAY button in playback.
6)
Press the RETURN button. (The tracking servo and the
sledding servo are turned OFF.)
sledding servo are turned OFF.)
7)
Check the level B of the oscilloscope’s waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B
×
100=less than ± 22%
Fig. 7-2-7.
Note :
A clear RF signal waveform means that the shape “≈” can
be clearly distinguished at the center of the waveform.
be clearly distinguished at the center of the waveform.
8)
Press the RETURN 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 6.
servo are turned ON.) Confirm the C (DC voltage) is almost
equal to the A (DC voltage) is step 6.
9)
Remove the soldering installed in step 3.
Fig. 7-2-8.
Fig. 7-2-9.
Center of the waveform
B
A (DC voltage)
level : 13.
±
0.6 Vp-p
0V
Traverse waveform
level : 1.3 Vp-p
+0.25
–0.20
–0.20
VOLT/DIV : 200mV
TIME/DIV : 500ns
TIME/DIV : 500ns
RF signel waveform
C (DC voltage)
Tracking servo
Sled servo
ON
Tracking servo
Sled servo
OFF
Traverse waveform
7-5
2-4-4. RF PLL Free-run Frequency Check (BD-21 Board)
Signal
Reference disc
Measurement
TP PLCK
point
Measuring
Frequency counter
instrument
Specified
4.3218 MHz
value
[Check Method]
1)
1)
Connect frequency counter to TP (PLCK) with lead wire.
2)
Turned Power switch on.
3)
Put the disc (YEDS-18) in to play the number five track.
Confirm that reading on frequency counter is 4.3218 MHz.
Confirm that reading on frequency counter is 4.3218 MHz.
2-4-5. Clock Adjustment (CD-169 Board)
Measurement
IC305 pin *ª
point
Measuring
Frequency counter
instrument
Adjustment
CT301
element
Specified
13500000 ± 40 Hz
value
[Adjusting Method]
1)
1)
Connect the frequency counter to check point of the CD-169
board.
board.
2)
Adjust CT501 of the CD-169 board so that the frequency
counter read 13.5 MHz ± 40 Hz at STOP condition.
counter read 13.5 MHz ± 40 Hz at STOP condition.
2-5. SERVO SYSTEM ADJUSTMENT
2-5-1. RF Switching Position Adjustment (MA-303 Board)
[Adjustment Object]
To adjust the link of the Ach and Bch of the tape playback outputs.
If this specification is not satisfied, the noise will increase and
cracking sounds will be produced.
To adjust the link of the Ach and Bch of the tape playback outputs.
If this specification is not satisfied, the noise will increase and
cracking sounds will be produced.
Mode
Playback
Signal
Alignment tape : Color bar portion
Measurement
CH1 : LINE-1 OUT VIDEO terminal
point
CH2 : CN502 pin3 (RF SWP)(RP-233 board)
Measuring
Oscilloscope
instrument
Adjustment
RV202
element
Specified
6.5 ± 0.5H (416 ± 32
µ
sec)
value
[Adjusting Method]
1)
1)
Set TRACKING switch (Remote commander) to MANUAL.
(“Auto tracking” display will disappear on the display window
indicator.)
(“Auto tracking” display will disappear on the display window
indicator.)
2)
Press the tracking buttons $ and 4 and adjust the tracking
position to the center.
position to the center.
3)
Adjust to 6.5 ± 0.5H (413 ± 32
µ
sec) using RV202.
Fig. 7-2-10.
Fig. 7-2-11.
Normal tracking
TV screen
Moves to the right when the
4
button in pressed
and to the left when the
$
button is pressed.
Approx. 1Vp-p
Approx. 5Vp-p
V
CH1
CH2
CH1
CH2
CN502 pin
CN502 pin
3
(RF SWP)
Enlargemant
Vertical sync. signal
6.5
±
0.5H
(416
±
32
µ
sec.)
7-6
2-6. VIDEO SYSTEM ADJUSTMENTS
For the video system adjustment, follow the adjustment procedures
given below as a rule. The color bar video signal supplied from the
pattern generator is used as the video input signal for the video
system adjustment of the recording mode. Check that the signal
satisfies the specified value designated in the “Check of input signal
(Fig. 7-2-2)”.
[Adjustment Sequence]
1)
given below as a rule. The color bar video signal supplied from the
pattern generator is used as the video input signal for the video
system adjustment of the recording mode. Check that the signal
satisfies the specified value designated in the “Check of input signal
(Fig. 7-2-2)”.
[Adjustment Sequence]
1)
X'tal OSC Check
2)
SYNC AGC Check
3)
White Clip/Dark Clip Check
4)
REC Y Level Check
5)
REC Chroma Level Check
6)
Playback Level Check
2-6-1. X'tal OSC Check (MA-303 Board)
Mode
Playback
Signal
Alignment tape : Color bar portion
Measurement
IC304 pin8
point
Measuring
Oscilloscope and Frequencycounter
instrument
Specified
PAL
: 4,433,619 ± 82 Hz
value
NTSC
: 3,579,545 ± 82 Hz
Note :
A frequency counter should be connected through a buffer
ampifier (oscilloscope, etc.) having a high impedance and a
low capacitance.
ampifier (oscilloscope, etc.) having a high impedance and a
low capacitance.
[Check Method]
1)
1)
Check that the oscillation frequency satisfies the specified value
and that the oscillation voltage A is 300 ± 130 mVp-p (PAL)/
250 ± 110 mVp-p (NTSC).
and that the oscillation voltage A is 300 ± 130 mVp-p (PAL)/
250 ± 110 mVp-p (NTSC).
Fig. 7-2-12.
2-6-2. SYNC AGC Check (MA-303 Board)
Mode
E-E
Signal
Color bar
Measurement
LINE-1 OUT VIDEO terminal
point
(terminated at 75
Ω
)
Measuring
Oscilloscope
instrument
Specified
A=1.0 ± 0.14 Vp-p
value
[Check Method]
1)
1)
Check that the SYNC AGC level (A) satisfies the specified
value.
value.
Fig. 7-2-13.
2-6-3. White Clip/Dark Clip Check (MA-303 Board)
Mode
E-E
Signal
Color bar
Measurement
IC302 pin$•
point
Measuring
Oscilloscope
instrument
Specified
White clip : A=190 ± 15%
value
Dark clip : B=52 ± 10%
[Check Method]
1)
1)
Check that the white clip level A is 190±15% to the white
(100%) level.
(100%) level.
2)
Check that the dark clip level B is 52±10% to the white (100%)
level.
level.
Fig. 7-2-14.
A
White (100%)
A
H
White (100%)
100%
H
A
B
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