Panasonic WV-BM990 Service Manual page 6

Loosen Deflection Coil Holding Screw.
Deflection Coil
Fig. 4-1
8
Turn the Deflection Coil until the raster becomes straight
on the monitor screen.
8
Tighten the Deflection Coil Holding Screw carefully.
Note: When fixing the Deflection Coil Holding Screw, push
the Deflection Coil to connect to CRT tightly.
(4). Centering and Horizontal Size Adjustment
Adjust: VR301 (CONTRAST)
VR302 (BRIGHT)
Centering Magnets
L501 (H.SIZE)
Observe: Video Monitor Screen
8
Supply the Monoscope Pattern signal to the Video Input
Connector.
8
Fix VR301 and VR302 at their center positions.
8
Adjust the Centering Magnets as shown in Fig. 4-1 until
the Monoscope Pattern signal comes to the center on the
monitor screen.
8
Adjust L501 so that the full Horizontal Width becomes plus
6% overscanning.
8
Repeat adjusting the Centering Magnets and L501 until
satisfactory.
(5). Vertical Height and Vertical Linearity Adjustment
Adjust: VR408 (V.SIZE)
VR412 (V.LINE)
Centering Magnets
Observe: Video Monitor Screen
8
Supply the Monoscope Pattern signal to the Video Input
Connector.
8
Fix VR301 and VR302 at their mechanical center positions.
8
Adjust VR408 so that the full Vertical Height becomes plus
6% overscanning.
8
Adjust VR412 so that the circle portion of the Monoscope
Pattern signal becomes nearly a true circle.
Centering Magnets
Main Board
Main Board
Main Board
Main Board
Main Board
– 3 –
8
Adjust the Centering Magnets so that the full Horizontal
Width and full Vertical Height become the same
overscanning rate.
8
Repeat adjusting VR408, VR412 and the Centering
Magnets until satisfactory.
(6). Focus Adjustment
Adjust: VR601 (FOCUS)
Observe: Video Monitor Screen
8
Supply the Monoscope Pattern signal to the Video Input
Connector.
8
Adjust the VR601 for the best focus in the monitor screen.
(7). Raster Distortion Adjustment
Adjust: Deflection Magnets
Observe: Video Monitor Screen
8
Supply the Crosshatch signal to the Video Input Connector.
8
Adjust 8 magnets as shown in Fig. 4-2 so that the raster
distortion becomes minimum.
Fig. 4-2
8
The raster distortion against 8 magnets are as shown in
Fig. 4-3.
Fig. 4-3
CRT Board
Adjust eight magnets.