Sony DPP-MS300 Service Manual ▷ View online
4-2
3. Input Signal Check
The video circuit adjustment uses as adjustment signals the video
signals obtained from the pattern generator, and therefore these
video output signals must be within the specification.
The video circuit adjustment uses as adjustment signals the video
signals obtained from the pattern generator, and therefore these
video output signals must be within the specification.
(1)
When S-VIDEO is input
Connect an oscilloscope to the Y signal pin of the S-VIDEO IN
connector, and check that the sync signal of Y signal is 286 mV,
video amplitude is 714 mV, and the setup level is 0 mV. (If using
the VTR with S-VIDEO OUT terminal, check further that the
chroma signal and burst signal do not remain.)
Also, connect an oscilloscope to the chroma signal pin of the S-
VIDEO IN connector, and check that the burst signal amplitude of
chroma signal is 286 mV and it is flat, and moreover, the ampli-
tude ratio of burst signal to chroma signal is 0.30 : 0.705. The Y
signal and chroma signal used for adjustment are shown in
Fig. 4-2.
connector, and check that the sync signal of Y signal is 286 mV,
video amplitude is 714 mV, and the setup level is 0 mV. (If using
the VTR with S-VIDEO OUT terminal, check further that the
chroma signal and burst signal do not remain.)
Also, connect an oscilloscope to the chroma signal pin of the S-
VIDEO IN connector, and check that the burst signal amplitude of
chroma signal is 286 mV and it is flat, and moreover, the ampli-
tude ratio of burst signal to chroma signal is 0.30 : 0.705. The Y
signal and chroma signal used for adjustment are shown in
Fig. 4-2.
Setup level: Potential difference between black and pedestal
Y signal
Chroma signal
Burst amplitude : chroma amplitude = 0.30 : 0.705
Fig. 4-2
Color bar signals of pattern generator
(at terminating resistance 75
(at terminating resistance 75
Ω
)
(2) When VIDEO is input
Connect an oscilloscope to the VIDEO IN terminal, and check
that the sync signal amplitude of VIDEO signal is 286 mV, video
amplitude is 714 mV, the setup level is 0 mV, and the burst signal
amplitude is 286 mV and it is flat. Also, check that the level ratio
of burst signal to red signal is 0.3 : 0.705.
The VIDEO signal (color bars) used for adjustment is shown in
Fig. 4-3.
Connect an oscilloscope to the VIDEO IN terminal, and check
that the sync signal amplitude of VIDEO signal is 286 mV, video
amplitude is 714 mV, the setup level is 0 mV, and the burst signal
amplitude is 286 mV and it is flat. Also, check that the level ratio
of burst signal to red signal is 0.3 : 0.705.
The VIDEO signal (color bars) used for adjustment is shown in
Fig. 4-3.
Fig. 4-3
Color bar signal of pattern generator
(at terminating resistance 75
(at terminating resistance 75
Ω
)
White (75%)
535
±
3 mV
714
±
3 mV
286
±
3 mV
Red
672
672
±
3 mV
Pedestal
Horizontal sync signal
Black
Burst signal
(to be flat)
286
±
3 mV
White (100%)
535
±
3 mV
714
±
3 mV
286
±
3 mV
White (75%)
White (100%)
Black
Pedestal
Horizontal
sync signal
Burst signal
(to be flat)
286
±
10 mV
Chroma
amplitude
4-3
POWER SUPPLY BLOCK
[Head Voltage Adjustment]
Before performing this adjustment, print the stair-step pattern
(Note 2) two times continuously with the old head (Note 1) or
normal unit. The second print will be used as a sample of the print
density.
(Note 2) two times continuously with the old head (Note 1) or
normal unit. The second print will be used as a sample of the print
density.
Note 1:
Only when the old head (faulty head) is not entirely damaged
with black or white lines.
with black or white lines.
Note 2:
To print the stair-step test pattern, turn on the power switch while
pressing the S1707 (CAPTURE) and S1717 (ENTER) on the SW-
40 board.
(Press the S1707 (CAPTURE) and S1717 (ENTER) until a peep
is heard.) Set the S1701 (Rotaly switch) to the position, and
press the S1706 (print), then the print will start.
pressing the S1707 (CAPTURE) and S1717 (ENTER) on the SW-
40 board.
(Press the S1707 (CAPTURE) and S1717 (ENTER) until a peep
is heard.) Set the S1701 (Rotaly switch) to the position, and
press the S1706 (print), then the print will start.
Note 1:
To print the stair-step test pattern, turn on the power switch while
pressing the S1707 (CAPTURE) and S1717 (ENTER) on the SW-
40 board.
(Press the S1707 (CAPTURE) and S1717 (ENTER) until a peep
is heard.) Set the S1701 (Rotaly switch) to the position, and
press the S1706 (print), then the print will start.
pressing the S1707 (CAPTURE) and S1717 (ENTER) on the SW-
40 board.
(Press the S1707 (CAPTURE) and S1717 (ENTER) until a peep
is heard.) Set the S1701 (Rotaly switch) to the position, and
press the S1706 (print), then the print will start.
Adjustment Procedure:
(1)
(1)
To print the stair-step test pattern, turn on the power switch
while pressing the S1707 (CAPTURE) and S1717 (ENTER)
on the SW-40 board.
(Press the S1707 (CAPTURE) and S1717 (ENTER) until a
peep is heard.) Set the S1701 (Rotaly switch) to the posi-
tion, and press the S1706 (print), then the print will start.
while pressing the S1707 (CAPTURE) and S1717 (ENTER)
on the SW-40 board.
(Press the S1707 (CAPTURE) and S1717 (ENTER) until a
peep is heard.) Set the S1701 (Rotaly switch) to the posi-
tion, and press the S1706 (print), then the print will start.
(2)
After printing, repeat (1) immediately.
(3)
Compare the second printed pattern density with that of the
sample, and if the density differs, perform the following ad-
justment.
sample, and if the density differs, perform the following ad-
justment.
(4)
Adjust VR201 according to the print density.
If darker than the sample: Decrease the head voltage.
If lighter than the sample: Increase the head voltage.
If darker than the sample: Decrease the head voltage.
If lighter than the sample: Increase the head voltage.
(5)
Print the stair-step pattern two times continuously.
(6)
Compare the second printed pattern density with that of the
simple, and if the density differs, repeat steps (3) to (6).
simple, and if the density differs, repeat steps (3) to (6).
Note:
Only one print is required after the second time.
(7)
Turn off the power switch.
Mode
Test mode (Note 1)
Signal
Test pattern (Stair-step)
Measuring points
+: CN1943 2 pin (MD-40 board)
–: CN1943 3 pin
–: CN1943 3 pin
Measuring instrument
Digital Voltmerter
Adjustment part
VR201
Specification
Print density should be the same as the sample
Fig. 4-4 Stair-step pattern
* VR201 is in the power block (1-468-364-41).
Adjustment Location:
power block
VR201
4-4
VIDEO BLOCK
[Free-Run Frequency Adjustment (1)] (VI-40 board)
Note 1:
Connect IC108 5 pin to the GND via 0.1µF capacitor (chroma
signal grounded.)
signal grounded.)
Adjustment Procedure:
(1)
(1)
Connect IC108 7 pin to the GND via 1 M
Ω
resisitor.
(2)
Adjust CT102 so that the frequency counter reading satisfies
the specification value.
the specification value.
[Free-Run Frequency Adjustment (2)] (DK-40 board)
Adjustment Procedure:
(1)
(1)
Adjust CT500 so that the frequency counter reading satisfies
the specification value.
the specification value.
[910fh Adjustment] (DK-40 board)
Adjustment Procedure:
(1)
(1)
Adjust CT401 so that the digital voltmeter reading satisfies
the specification value.
the specification value.
[Y/C Separation Y Level Adjustment] (VI-40 board)
Adjustment Procedure:
(1)
(1)
Adjust RV103 so that the A level (white) of waveform on
the oscilloscope satisfies the specification value.
the oscilloscope satisfies the specification value.
Fig. 4-5
Mode
VIDEO Input
Signal
Color bar (S-VIDEO IN) (Note 1)
Measuring point
IC108 !• pin
Measuring equipment
Frequency Counter
Adjustment part
CT102
Specification value
3.579545 MHz ± 30 Hz
Mode
VIDEO Input
Signal
Color bar (S-VIDEO IN)
Measuring point
IC407 `⁄⁄‹ pin
Measuring equipment
Frequency Counter
Adjustment part
CT500
Specification value
14.31818 MHz ± 100 Hz
Mode
VIDEO Input
Signal
Color bar (VIDEO IN)
Measuring point
CL138
Measuring equipment
Oscilloscope
Adjustment part
RV103
Specification value
1.00 ± 0.02Vp-p
[Y/C Separation CHROMA Level] (VI-40 board)
Adjustment Procedure:
(1)
(1)
Adjust RV102 so that the A level (white) of waveform on
the oscilloscope satisfies the specification value.
the oscilloscope satisfies the specification value.
Fig. 4-6
[D/A Output Y Level Adjustment] (DK-40 board)
Note:
Turn of the power switch once, then turn it on again.
Adjustment Procedure:
(1)
(1)
Adjust RV401 so that the A level (white) of waveform on
the oscilloscope satisfies the specification value.
the oscilloscope satisfies the specification value.
Fig. 4-7
Mode
VIDEO Input
Signal
Color bar (VIDEO IN)
Measuring point
J1802 (OUTPUT)
Measuring equipment
Oscilloscope
Adjustment part
RV401
Specification value
535 ± 15 mVp-p
White (75%)
H
A
Mode
VIDEO Input
Signal
Color bar (S-VIDEO IN)
Measuring point
IC401 !¡ pin (or CL427)
Measuring equipment
Digital Voltmeter
Adjustment part
CT401
Specification value
2.5 ± 0.1 Vdc
White (100%)
H
A
Mode
VIDEO Input
Signal
Color bar (VIDEO IN)
Measuring point
CL129
Measuring equipment
Oscilloscope
Adjustment part
RV102
Specification value
286 ± 6 mVp-p
A
H
4-5
[D/A Output CHROMA Level Adjustment] (DK-40 board)
Adjustment Procedure:
(1)
(1)
Adjust RV402 so that the A level (Red) of waveform on the
oscilloscope satisfies the specification value.
oscilloscope satisfies the specification value.
(2)
Turn off the power switch.
Fig. 4-8
[A/D Input Y Level Adjustment] (DK-40 board)
Note:
Turn off the power switch once, then turn it on again.
Adjustment Procedure:
(1)
(1)
Connect on oscilloscope to the CL409 (from IC407 ^¢ pin
to the point via R478).
to the point via R478).
(2)
Adjust RV404 so that the A level (white) of waveform on
the oscilloscope satisfies the specification value.
the oscilloscope satisfies the specification value.
Fig. 4-9
Mode
VIDEO Input
Signal
Color bar (S-VIDEO IN)
Measuring point
CL409
Measuring equipment
Oscilloscope
Adjustment part
RV404
Specification value
1.05 ± 0.03 Vp-p
[A/D Input R-Y/B-Y Level Adjustment]
(VI-40, DK-40 board)
(VI-40, DK-40 board)
Adjustment Procedure:
(1)
(1)
Connect on oscilloscope to the CL408.
(2)
Adjust RV105 so that waveform to be Fig. 4-10.
Fig. 4-10
(3)
Adjust RV106 so that the A level (B-Y) of waveform on the
oscilloscope satisfies the specification value.
oscilloscope satisfies the specification value.
Fig. 4-11
(4)
Connect on oscilloscope to the CL407.
(5)
Adjust RV405 so that the A level (R-Y) of waveform on the
oscilloscope satisfies the specification value.
oscilloscope satisfies the specification value.
Fig. 4-12
Mode
VIDEO Input
Signal
Color bar (S-VIDEO IN)
Measuring point
CL407, 408
Measuring equipment
Oscilloscope
Adjustment parts
RV105, 106, 405
Specification value
CL407 (R-Y) 1.03 ± 0.02 Vp-p
CL408 (B-Y) 1.30 ± 0.02 Vp-p
CL408 (B-Y) 1.30 ± 0.02 Vp-p
Red
Yellow
A
Mode
VIDEO Input
Signal
Color bar (VIDEO IN)
Measuring point
J1802 (OUTPUT)
Measuring equipment
Oscilloscope
Adjustment part
RV402
Specification value
672 ± 15 mVp-p
Red
A
H
White (75%)
H
A
A
B
C
Yellow
C 1/4A
B 2/3A
B 2/3A
Blue
Yellow
A
Click on the first or last page to see other DPP-MS300 service manuals if exist.