Beam Form Adjustment; Lens Focus Adjustment - Hitachi C43-FD5000 Service Manual

SERVICE ADJUSTMENTS

2.10 BEAM FORM ADJUSTMENT

Adjustment Preparation
(1) The beam alignment should have been completed.
(2) The raster inclination, centering, horizontal and vertical size adjustments should be completed. Optical focus
should be coarsely adjusted.
(3) VIDEO control should be set to Factory Preset condition. (Contrast: Max；other item: Center)
(4) Input the dot signal.
Adjustment Procedure
(1) Green PRT beam shape adjustment. Short-circuit 2P sub-mini connectors on Red and Blue CPT P.W.Bs. to
project only the green beam.
(2) Turn the green static VR
Note : Blooming
(3) Make the dot at the screen center a true circle using the 4-pole magnet shown below.
(4) Repeat the procedure for the Red
(5) After complete the adjustment, return R, G and B static VRs to the best focus point.
(6) After complete the beam alignment, fix the beam alignment magnet with white paint.
*1
*2 Static Focus VR is on FOCUS PACK UFPK
*3
True circle specification
a
True circle Form Ratio: a/b
Specification : 0.9~1.1

2.11 LENS FOCUS ADJUSTMENT

Adjustment Preparation
(1) The orientation of PTV set is arbitrary, west, east, north and south.
(2) Centering DY inclination should be adjusted.
(3) Electrical focus adjustment should have been completed.
(4) Drive VR location adjustment should have been completed.(Red : 12 0'clock, Green : 1~2 0'clock)
(5) Receive the NTSC cross-hatch signal.
Contrast control should be set Center and Brightness control should be set minimum.
Adjustment Procedure
(1) Loosen the fixing screws or wing nuts 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(7Kgfcm) ~1.18N.m(12Kgfcm). (Do not turn the lens cylinder after tighten
the screws and wing nuts. Also do not over tighten the screw, otherwise the lens might be tilted or the screw
might be broken).
*1
fully clockwise.
*2
and Blue
b
*3
PRT beam shapes
4-pole beam shape
correction magnet
2-pole beam alignment
magnet
21
PRT surface side
PRT E. gun side