Pioneer AVH-P7950DVD/CN5, Service Manual

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AVH-P7950DVD/RC
59
5 6 7 8
5 6
7
8
C
D
F
A
B
E
Check 11: Is the video circuit OK?
<Outline> Composite signal and component signal are output from DVD-LSI (IC1501), and are output from the
HOST I/F (CN1901) via a buffer circuit.
CN1901
HOST I/F
AVCC5
Composite
Component Y
Component Cb
Component Cr
COMPO
Fig 11.1: Video circuit
<Checking method> Playback DVD-REF-A1 TITLE2 CHAPTER5 (WHITE 100%), and monitor COMPO signal with
an oscilloscope with GNDV1 (stylus) being the reference. Set the trigger mode to "TV trigger" and
the trigger line to "150 line".
Video buffer circuit
IC1501
DVD_LSI
Video
DAC
section
NO.
Check point 1 (stylus)
Specification value Reference waveform
1 COMPO 1 000 mVpp
±
5 % Waveform 6
In case of NG, check the applicable line, the periphery of the major components in the drawing above, soldering of the
peripheral components and defective components.
PEAK
COMPO signal
Reference
value
Color burst
Pedestal level
BOTTOM
Horizontal sync signal
Fig 11.2: Waveform for the case of composite white 100% output
<Video level readjustment method>
In case the video composite output is outside of the specification value, readjust the level according to the method
described below.
(Note : Units are exchanged, the video output is not adjusted. )
Turn the volume (VR1671) to adjust the video level within the range of 1.0
±
0.02 Vpp.
The adjustment specification is 1.0
±
0.02 Vpp.
Adjust this level within the
range of 1.0
±
0.02 Vpp.
AVCC5
Fig 11.3: Video circuit (component)
Q1702
Video buffer circuit
Q1701
Video buffer circuit
Q1704
Video buffer circuit
CN1901
HOST I/F
Y Y
Cb Cb
Cr Cr
IC1501
LSI
Video
DAC
section