Beam Form Adjustment; Side Pin Distortion, Vertical Size, Horizontal Size, Trapezoid Distortion Adjustment - Hitachi 51F710 Service Manual

2.7 Beam form adjustment

Adjustment preparation
(1) Raster Position should have been completed.
(2) The raster tilt and centering should have been
completed.
(3) Set video conditions to factory preset.
(4) Input the dot signal.
(5) Set Aspect to 4:3 Standard Mode.
Adjustment procedure
(1) Green PRT beam shape adjustment. Short-
circuit TS (2p EH) 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 the BEAM FORM is completed, fix the
BEAM FORM magnet with white paint.
PRT SURFACE SIDE
ZERO FIELD
SPACER (NO
ADJUSTMENT)
TRUE CIRCLE SPECIFICATION
b
TRUE CIRCLE DEGREE: a/b
a
2.8 SIDE PIN DISTORTION & VERTICAL SIZE &
HORZONTAL SIZE & TRAPEZOID DISTORTION
ADJUSTMENT
Adjustment preparation
(1) Receive any NTSC signal.
(2) VIDEO control should be set Factory Preset
condition.
(3) BEAM FORM adjustment should be finished.
Adjustment procedure
NORMAL MODE
(1) With the unit on, and the R/C in DCAM mode.
(2) Press the service button and press the [MUTE]
key on R/C at the same time. Uncorrected
crosshatch is displayed.
(3) Press and hold the [MENU] key on the front
panel for 3 seconds, then I
BACK TO ADJUSTMENTS
4-POLE BEAM
SHAPE CORRECTION
MAGNET
2-POLE BEAM
ALIGNMENT
MAGNET
SPECIFICATION: 1.0-1.1
2 C menu is displayed.
SIDE PIN DISTORTION
(3) Choose "EW PARA" (SIDE PIN) item by using
[MENU] key and
(4) Adjust SIDE PIN as follows using
Left and right side edge of vertical DCU cross-hatch line
should be straight condition.
NOTE: If it's impossible to adjust the straight
line, set a little pin condition.
VERTICAL SIZE
(5) Choose "V SIZE" item by using
(6) Adjust V SIZE as follows using
V. Size
Specification
51" 560
57" 625
65" 710
Tolerance: ± 5mm
Units = mm
HORIZONTAL SIZE
(3) Choose "H SIZE" item by using ,
H. Size
Specification
51" 1070
57" 1195
65" 1365
Tolerance: ± 5mm
Units = mm
8
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