21
•
When complete readjustment is necessary or a new
picture tube is installed, carry out the following
adjustments.
•
Unless there are specific instructions to the contrary,
carry out these adjustments with the rated power supply.
•
Unless there are specific instructions to the contrary, set the
controls and switches to the following settings:
Contrast
...............
normal
Brightness
...............
normal
Carry out the following adjustments in this order:
3-1.
Beam Landing
3-2.
Convergence
3-3.
Focus
3-4.
White balance
Note:
Test equipment required
1.
Color bar/pattern generator.
2.
Degausser.
3.
Digital multimeter.
4.
Oscilloscope.
SECTION 3
SET-UP ADJUSTMENTS
3-1. BEAM LANDING
Preparation:
1.
In order to reduce the influence of geomagnetism on the set’s
picture tube, face it in an easterly or westerly direction.
2.
Switch on the set’s power and degauss with the
degausser.
(1)
Adjustment of Correction Magnet for Y-Splitting
Axis
1.
Input a crosshatch signal from the pattern generator.
2.
Set the Picture control to minimum and confirm that the
Brightness control is set to normal.
3.
Position the neck assembly as indicated in Fig.3-2.
4.
Move the deflection yolk as far forward as is possible.
5.
Adjust the upper and lower pin symmetrically by opening or
closing the Y-splitting axis correction magnets located on the
neck assembly.
6.
Return the deflection yolk to its original position.
Caution :
High voltages are present on the Deflection yolk terminals - take care
when handling the Deflection yolk whilst carrying out adjustments.
(2) Landing
Note :Before carrying out the following adjustments
adjust the magnets as indicated below [See Fig.3-3].
1.
Input an all-white signal from the pattern generator.
Maximize the picture setting and adjust the Brightness
setting.
2.
Rough-adjust the focus and horizontal convergence.
3.
Loosen the deflection yolk screws and align the purity
adjustment knob to its central position. [See Fig.3-1].
4.
Switch from the all-white pattern to an all-green pattern.
5.
Move the deflection yolk backwards and adjust with the
purity magnet so that the green is at the centre and it aligns
symmetrically. [See Fig.3-4].
6.
Move the deflection yolk forward and adjust so that the
entire screen becomes green.
7.
Switch the raster signal to red, then to blue and verify the
landing condition.
8.
When the position of the deflection yolk has been determined,
fasten the deflection yolk with the screw.
9.
If the beam does not land correctly in all the corners of the
screen, use magnets to correct it. [See Fig.3-5].
Y-splitting axis correction magnet
Fig.3-1
Fig.3-2
Purity
Align Pips
on each
magnet
Neck assy
Align the bottom edge
of the neck assy with
the G3 hole centre.
Deflection yoke
Fig.3-3
