Static Focus Adjustment - Hitachi C47-WD7000 Service Manual

SERVICE ADJUSTMENTS

2.12 STATIC FOCUS ADJUSTMENT

Preparation for adjustment
(1)The raster inclination, centering, horizontal/vertical amplitude and optical/electrical focus and beam alignment
should be adjusted.
(2) The static convergence data should be cleared.
(3) Contrast control should be set MAX and Brightness control should be set Center.
(4) Receive the Hitachi circle pattern signal.
(5) Apply covers to the others then adjust lenses and project only single color on the screen.
Adjustment procedure
(1) Red static focus adjustment.
Vary the static focus VR on Focus pack (UFPK) so that the right edge of Hitachi mark circle pattern is the
best clear. Check that the focus does not get conspicuously worse at other check point on the cross-hatch
signal.
(2) Blue static focus adjustment.
Vary the static focus VR on Focus pack (UFPK) so that the Hitachi mark on the circle pattern center is
the best clear. Check that the focus does not get conspicuously worse at all edges of the cross-hatch
signal.
(3) Green static focus adjustment.
Vary the static focus VR on Focus pack (UFPK) (for green) so that the Hitachi mark on the circle pattern
center is the best clear. Check that the focus does not get conspicuously worse at checking point on
the picture periphery and the cross-hatch signal.
Remarks
Checking point for the periphery of picture.
Checking point
43