Hitachi 61HDX98B Service Manual page 48

BEAM FORM ADJUSTMENT for the DP-85 CHASSIS
BEAM FORM
Preparation for adjustment Adjustments procedure:
7) IMPORTANT: Screen for- I) Green CRT beam shape ad- 4
mat should be WORMAL ". justment.
2) The beam alignment should 2) Short-circuit 2P sub-mini
have been completed. connectors on Red and Blue
2) The Yoke Tilt, centering,
CRT PWB to project only
3
4
horizontal/vertical amplitude the Green beam.
5)
and optical focus adjust- 3) Turn the green static focus
ments should have been VR fully clockwise.
completed.
Brightness: 90%, Contrast:
6)
Max..
Input a NTSC DOT signal.
Make the dot at the screen
center a true circle as
shown in Figure 2, using
the 4-Pole magnet shown in
Figure 7.
Also adjust the Red and
Blue CRT beam shapes ac-
cording to the steps (1) to
(3).
After the adjustment is
completed, return R, G and
B static VRs to the Best Fo-
cus point.
BEAM ALIGNMENT AND FORM MAGNETS
ADJUSTMENT
PICTURE TUBE SIDE
TABS
,
4-POLE BEAM SHAPE
CORRECTION MAGNET
ZERO FIELD SPACER
(NO ADJUSTMENT)
2-POLE BEAM
ALIGNMENT MAGNET
TRUE CIRCLE
DEGREE a/b
SPECIFICATION
a: 0.9
b: 1.1
Figure 2
Figure 1
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