Power Board / Inverter Board / Switch Board - Panasonic WE-MV180A Service Manual

3. Connection and Reference Levels
for Adjustment
3.1. Connection
8
The Fig. 3-1 shows the connection diagram for the
adjustment procedure.
Video Imager
WE-MV180A
Video
Board
S-Video
Video
Input
Signal
Board
Composite
Generator
Video
8
Connect the Underscanned Colour Video Monitor to the
Composite Video Output Connector of the WE-MV180A
through the Vectorscope using the coaxial cables.
8
Terminate the input terminal of the Underscanned Colour
Video Monitor with 75 Ω.
8
Connect the RGB Video Output Connectors to the R, G, B
and Sync Input Terminals of the RGB Colour Video
Monitor.
8
Connect the S-Video Signal from the Video Signal
Generator to the S-Video Input Connector 1 or S-Video
Input Connector 2.
8
Connect the probe of the Digital Voltmeter, Oscilloscope
or Frequency Counter at the desired Test Point in each
adjustment step.
8
The adjustments should be done more than three minutes
warm-up.
3.2. Reference Levels Confirmation for
Adjustment
S-Video Signal
8
Supply 100% Colour Bar signal to the S-Video Input
Connector 1.
8
Select the A/V 1 mode by the Input Selector.
8
Connect the Oscilloscope to TP14 on the Video Board and
note the signal level as reference (Vy) as shown in Fig. 3-
2.
Underscanned
Colour Video
Vectorscope
Monitor
Composite
Video Out
RGB Colour
Video Monitor
R Out
G Out
B Out
Sync Out
Fig. 3-1
S-Video Signal
Reference Y Signal (Vy)
Fig. 3-2
8
Change the connection of the Oscilloscope to TP15 on the
Video Board and note the signal level as reference (Vc) as
shown in Fig. 3-3.
75 Ω
Composite Video Signal
8
Supply 100% Colour Bar signal to the Composite Video
Input Connector 1.
8
Connect the Oscilloscope to TP16 on the Video Board and
note both Luminance signal level (Vycm) and Burst signal
level (Vccm) as reference as shown in Fig. 3-4.
Composite
Video Signal
Reference
Burst Signal
(Vccm)
4. Adjustment Procedure
8
Refer to the Location of the Test Points and
Adjusting Controls on the page 17.
8
All adjustments should be made with the Ceramic
Screwdriver.
Power Board
(1) +12V Adjustment
Test Point:
Adjust:
8
Connect the Digital Voltmeter to the pins 1 and 3 of CN14.
8
Adjust VR1 to obtain between +12.1 and +12.2 V DC.
5
S-Video Signal
Reference Burst Signal
(Vc)
Fig. 3-3
Fig. 3-4
Pin 1 of CN14 (+12V)
Pin 3 of CN14 (GND)
VR1 (+12V)
Composite
Video Signal
Reference
Y Signal
(Vycm)
Power Board
Power Board
Power Board