Sony DPP-MS300 Marketing, Service Manual

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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.
(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.
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
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.
Fig. 4-3 Color bar signal of pattern generator
(at terminating resistance 75
Ω
)
White (75%)
535
±
3 mV
714
±
3 mV
286
±
3 mV
Red
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