Sharp 50NP4, Service Manual

Page: 39 / 121

39
Notes: (1) Progressive mode should be adjusted
before HD mode.
(2) If internal cross-hatch does not appear after
clearing RAM data, press service switch
again.
(3) To restore old RAM data, turn TV off and on.
TRUE CIRCLE DEGREE: a/b
SPECIFICATION: 0.9-1.1
PRT SURFACE SIDE
4-POLE BEAM
SHAPE CORRECTION
MAGNET
2-POLE BEAM
ALIGNMENT
MAGNET ZERO FIELD
SPACER (NO
ADJUSTMENT)
b
a
2.9 Beam form adjustment
Adjustment preparation
(1) The beam alignment should have been
completed.
(2) The raster tilt, centering, horizontal/
vertical size, scanning area check, and raster
distortion should have been completed.
(3) Set video conditions to factory preset.
(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.B.s to project only the Green beam.
(2) Turn the green static focus VR, on the Focus
Pack, fully clockwise. (Blooming)
(3) Make the dot at the screen center a true circle
using the 4-pole magnet as shown below.
(4) Also adjust the Red and Blue PRT beam shapes
according to the steps (1) to (3).
(5) After the adjustment has been completed, return
R, G and B static VRs to the just focus point.
(6) After completed, fix beam form magnet with
white paint.
TRUE CIRCLE SPECIFICATION
2.10 LENS FOCUS ADJUSTMENT
Adjustment preparation
(1) The orientation of PTV set is arbitrary, west,
east, north and south.
(2) Centering DY inclination should have been
adjusted.
(3) Electrical focus adjustment should have been
completed.
(4) Drive VR location dajustment should have been
completed. (Red : 12 OÕclock, Green : 1~2
OÕclock).
(5) Receive the cross-hatch pattern signal.
(6) Refer to set below.
CONTRAST : HALF of full scale.
BRIGHTNESS : minimum
Adjustment procedure
(1) Loosen the fixing screww 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 scres or wing nuts for each lens with a
torque of 1.18N.m (12Kgf cm) ~ 1.67N.m (17Kgf
cm). (Be careful the lens cylinder does not turn
after having tightened the screw or wing nuts. If
it is tightened too much, lens may tilt or screw
may break.)
(2) Apply covers to each color of R, G and B lenses.
And project a single color 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 turned clockwise
viewed from the front, the color Aberration
change as follows.
(NOTE 1)
Fixing Screw
(NOTE 2)
Wing Nut
TYPE 1 TYPE 2
Lens Sass
Lens Sass
Color
Aberration
Cross-Hatch
Change of Color Aberration
Short focus Long focus
RED LENS Orange Scarlet
GREEN LENS Blue Red
BLUE LENS Purple Green