Sony DPP-MS300E Service Manual page 21

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 300 mV,
video amplitude is 700 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 300 mV and it is flat, and moreover, the ampli-
tude ratio of burst signal to chroma signal is 0.30 : 0.66. 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
White (100%)
Approx. 700 mV
Pedestal
Chroma signal
Chroma
amplitude
Burst amplitude : chroma amplitude = 0.30 : 0.66
Fig. 4-2 Color bar signals of pattern generator
(at terminating resistance 75 Ω )
Black
Approx.
300 mV
Horizontal
sync signal
300 ± 10 mV
Burstsignal
to be flat
4-2
(2) When VIDEO is input
Connect an oscilloscope to the VIDEO IN terminal, and check
that the sync signal amplitude of VIDEO signal is 300 mV, video
amplitude is 700 mV, the setup level is 0 mV, and the burst signal
amplitude is 300 mV and it is flat. Also, check that the level ratio
of burst signal to red signal is 0.3 : 0.66.
The VIDEO signal (color bars) used for adjustment is shown in
Fig. 4-3.
Approx.
0.7 V
Approx.
0.3 V
Horizontal sync signal
Fig. 4-3 Color bar signal of pattern generator
(at terminating resistance 75 Ω )
White (Approx. 100%)
Burst signal
(To be flat)
Approx.
0.3 V
Red