Read Panasonic WV-BM1790CH Service Manual online
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1. Test Equipment Required
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The following test equipments are required for adjustment
of the Video Monitor WV-BM1790CH.
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Video Signal Generator (Monoscope Pattern signal,
Stairstep signal and Cross-hatch signal)
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Frequency Counter
2. Disassembling Procedure for
Adjustment
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Referring to Fig. 2-1, remove eight screws that secure the
Upper Cover and remove the Upper Cover.
Fig. 2-1
3. Connection and Setting Up for
Adjustment
3.1. Connection
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The Fig. 3-1 shows the connecting diagram for adjustment
procedure of the WV-BM1790CH using the Video Signal
Generator.
Fig. 3-1
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Connect the Video Output Connector of the Video Signal
Generator to the Video Input Connector of the WV-
BM1790CH.
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Connect the probe of the Frequency Counter to desired
Test Point in each adjustment step.
ADJUSTMENT PROCEDURE
3.2. Setting Up
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Set the Video Signal Generator so that it provides the
Monoscope Pattern signal.
3.3. Initial Position of the Switches and
Level Controls for Adjustment
Main Board
TV Standard Selector (SW201).....................CCIR position
CONTRAST (VR101) ............................Mechanical Center
BRIGHT (VR102) ..................................Mechanical Center
V-HOLD (VR201) ..................................Mechanical Center
H-HOLD (VR301) ..................................Mechanical Center
V-HEIGHT (VR202) ...............................Mechanical Center
SUB V-HEIGHT (VR205) ......................Mechanical Center
V-LIN (VR204) .......................................Mechanical Center
CRT Board
SUB BRIGHT (VR103) ..........................Mechanical Center
FOCUS (VR104) ..................................Mechanical Center
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The adjustment should be done with this initial setting,
unless otherwise specified.
4. Adjustment Procedure
8
Refer to the Location of the Test Points and Adjusting
Controls on page 5.
(1). Sub-Brightness Coarse Adjustment
Test Point: Video Monitor Screen
Adjust:
VR201 (V-HOLD)
Main Board
VR301 (H-HOLD)
Main Board
VR101 (CONTRAST)
Main Board
VR103 (SUB BRIGHT)
CRT Board
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Supply the Monoscope pattern signal to the Video Input
Connector.
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Adjust VR201 to hold picture vertically.
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Adjust VR301 to hold picture horizontally.
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Turn the CONTRAST Control to fully clockwise.
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Adjust VR103 so that the raster will just appear.
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Turn the CONTRAST Control to its mechanical center
position.
Remove eight screws.
Upper Cover
WV-BM1790CH
Video Signal Generator
VIDEO IN
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