Hitachi C43-FD8000, Service Manual

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SERVICE ADJUSTMENTS
2.11 LENS FOCUS ADJUSTMENT
Adjustment preparation
(1) The orientation of PTV set is arbitrary, west, east, north and south.
(2) Centering DY tilt should be adjusted.
(3) Electrical focus adjustment should have been completed.
(4) Drive VR location adjustment should have been completed.
(5) Red : 12 0’clok, Green : 1~2 0’clock)
(6) Receive the NTSC cross-hatch signal.
(7) Contrast control should be set center and brightness control should be set minimum.
Adjustment procedure
(1) Loosen the fixing screw or wing nut on the lens cylinder so that the lens cylinder can be turned.
(Be careful not to loosen too much)
After completing steps (4), (5), (6) below, tighten the fixing screws or wing nuts for each lens with a torque of
0.67N.m(7Kgf cm) ~ 1.18N.m(12Kgf cm).
(Do not turn the lens cylinder after having a screw and wing nuts tightened. Also do not tighten the screw too
much, otherwise the lens will be tilted too much or the screw will be broken).
Lens sass Lens sass
(NOTE1) (NOTE2)
Fixing screw Fixing wing nuts
TYPE 1 TYPE 2
(2) Apply covers to each colors of R, G and B lenses. And project a single color beam on the screen and adjust in
sequence. (The adjustment order of R, G and B is only an example.)
(3) If the lens adjustment knob is tuned clockwise viewed from the front, the color aberration change as follows.
Cross-Hatch Color aberration
Change of color aberration
Short focus Long focus
RED LENS Orange Scarlet
GREEN LENS Blue Red
BLUE LENS Purple Green