Set-Up Adjustments; Beam Landing - Sony KV-28WF1A Service Manual

KV-28WF1
•
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 these settings :
Contrast ............ 80% (or remote control
normal)
Brightness ........... 50%
Preparation:
•
In order to reduce the influence of geomagnetism on
the set's picture tube, face it east or west.
•
Switch on the set's power and degauss with the
degausser.

3-1. BEAM LANDING

1. Input the white signal with the pattern generator.
CONTRAST
normal
BRlGHTNESS
2. Set the pattern generator raster signal to red.
3. Move the deflection yoke forward and adjust with the
purity control so that the red is at the centre and the
blue and the green take up equally sized areas on
each side. (See Fig. 3-1 - 3-3)
4. Move the deflection yoke forward and adjust so that
the entire screen becomes red. (See Fig. 3-1)
5. Switch the raster signal to blue, then to green and
verify the condition.
6. When the position of the deflection yoke has been
decided, fasten the deflection yoke with the screws.
7. If the beam does not land correctly in all the corners,
use a magnet to adjust it. (See Fig. 3-4)
Fig. 3-1
SECTION 3

SET-UP ADJUSTMENTS

•
Carry out the following adjustments in this order :
1. Beam landing
2. Convergence
3. Focus
4. White balance
Note: Testing equipment required.
1. Color bar/pattern generator
2. Degausser
3. DC power supply
4. Digital multimeter
5. Oscilloscope
Fig. 3-2
Fig. 3-3
Fig. 3-4
— 24 —
Purity control
A buckle
G1
Deflection yoke
Green
Red
Blue
Disk magnets or
rotatable disk
Purity control corrects
magnets correct
this area.
these areas (a - d).
a b
d
c
Deflection yoke positioning
corrects these areas.
a
c
b
d
NECK ASSY
G2