Hitachi C43-FD2000, Service Manual

Page: 65 / 131

2.6 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) Contrast control should be set MAX
and Brightness control should be set
Center.
(3) Receive the Hitachi circle pattern
signal.
(4) 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
2.7 RASTER POSITION ADJUSTMENT
Preparation for adjustment
(1)
Place the set facing east or west.
(2) Receive the NTSC Hitachi circle pattern
signal. (Set the NTSC mode)
(3) Contrast control should be set Maximum and
the other controls should be set Center.
(4) The raster inclination and beam alignment
should be adjusted.
The lens focus and electric focus adjustment
should be coarsely adjusted.
(5) The convergence should be uncorrected
state.
(6) Turn the Main power SW off.
(7) Press and hold the “SERVICE ONLY” SW.
on CONV./FOCUS P.W.B. and switch on the
Main power.
(8) Press “SERVICE ONLY” SW again to
display the DCU’s cross-hatch pattern.
Adjustment procedure
(1)
Turn the centering magnets for R, G and B to
get the center point of the cross-hatch
position within specification as shown below.
R B
G
Geometric
center of the
screen
[
Horizontal direction
]
L
1
L
2
43” 20 30
50” 20 30
Unit: mm
R: L
1
to the left from the geometric
center of the screen.
L
1
+2mm
B: L
2
to the right from the
geometric center of the screen.
L
2
+2mm
G: To geometric center of screen.
[Vertical direction]
Both of the distance between the central
horizontal line of R,B and the geometric
center of the screen should be within
+2mm.
(2) Immediately after the adjustment is
completed, fix the R, G and B centering
magnets using white paint.
L
2
L
1