Sony KV-G21L3 Service Manual ▷ View online
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13
–
KV
-G21L3
-G21L3
RM-883
2-6. PICTURE TUBE REMOVAL
•
REMOVAL OF ANODE-CAP
NOTE : After removing the anode short circuit the anode of the picture tube and
the anode cap to the metal chassis, CRT shield or carbon paint on the
CRT.
CRT.
•
REMOVING PROCEDURES
1
Turn up one side of the rubber cap in the direction indicated by the arrow
a
.
a
a
3
C board
1
Anode cap
Cushion
2
A board
4
Deflection yoke
5
Four screws
(Tapping screws)
b
b
2
Using a thumb press down then pull up the rubber cap firmly in the direction
indicated by the arrow
indicated by the arrow
b
.
3
When one side of the rubber cap is separated from the anode button, the
anode-cap can be removed by turning up the rubber cap and pulling it up in the
direction of the arrow
anode-cap can be removed by turning up the rubber cap and pulling it up in the
direction of the arrow
c
.
c
Anode button
•
HOW TO HANDLE AN ANODE-CAP
1
Do not damage the surface of anode-caps with sharp shaped objects
2
Do not press the rubber too hard so as not to damage the inside of anode-caps
A metal fitting called the shatter-hook terminal is built into the rubber.
A metal fitting called the shatter-hook terminal is built into the rubber.
3
Do not turn the foot of rubber over too hard
The shatter-hook terminal will stick out or damage the rubber.
The shatter-hook terminal will stick out or damage the rubber.
Anode Button
– 14 –
KV-G21L3
RM-883
•
The following adjustments should be made when a complete
realignment is required or a new picture tube is installed.
•
These adjustments should be performed with rated power
supply voltage unless otherwise noted.
Controls and switch should be set as follows unless otherwise noted:
PICTURE control ........................................................... normal
BRIGHTNESS control ................................................... normal
Perform the adjustments in the following order
1. Beam Landing
2. Convergence
3. Focus
4. White Balance
Note : Test Equipment Required:
1. Color-bar/Pattern Generator
2. Degausser
3. Oscilloscope
SECTION 3
SET-UP ADJUSTMENTS
................................................................................................................................................................................................................................
Preparation :
•
In order to reduce the influence of geomagnetism on the set's
picture tube, face it east or west.
•
Switch on the power and degauss with the degausser.
3-1. BEAM LANDING
1. Input a white signal with the pattern generator.
Contrast
Brightness
2. Set the pattern generator raster signal to a green raster.
3. Move the deflection yoke to the rear and adjust with the purity
control so that the green is at the center and the blue and the red
take up equally sized areas on each side.
(See Figures 3-1 through 3-3.)
4. Move the deflection yoke forward and adjust so that the entire
screen is green. (See Figure 3-1.)
5. Switch the raster signal to blue, then to red and verify the
condition.
6. When the position of the deflection yoke has been decided,
fasten the deflection yoke with the screw.
7. If the beam does not land correctly in all the corners, use a
magnet to adjust it.
(See Figure 3-4.)
Fig. 3-1
Purity coutrol
Fig. 3-2
Fig. 3-4
Deflection yoke positioning
corrects these areas.
Purity control corrects
this area.
Disk magnets or rotatable
disk magnets correct
these areas (a-d).
disk magnets correct
these areas (a-d).
b
c
a
d
b
a
c
d
Fig. 3-3
GREEN
BLUE RED
Purity Control
}
normal
– 15 –
KV-G21L3
RM-883
R G B
G
R
B
Center dot
V.STAT Magnet
C board
RV 701
SCREEN (G2)
3-2. CONVERGENCE
Preparation :
•
Before starting this adjustment, adjust the focus, horizontal size
and vertical size.
•
Minimize the brightness setting.
•
Provide dot pattern.
(1)
Horizontal and Vertical Static Convergence
1. (Moving vertically), adjust the V.STAT magnet so that the red,
green and blue points are on top of each other at the center of
the screen.
2. (Moving horizontally), adjust the H.STAT magnet so that the
red, green and blue points are on top of each other at the center
of the screen.
3. Tilt the V.STAT magnet and adjust the static convergence by
opening or closing the V.STAT magnet.
B
R
B
R
a
b
b
b
a
b
a
b
a
R
G
B
b
B
G
R
b
b
a
a
1
2
3
G
G
B G R
R G B
•
Operation of V.STAT magnet.
If the V.STAT magnet is moved in the direction of the a and
b arrows, the red, green and blue points move as shown
b arrows, the red, green and blue points move as shown
below.
•
Operation of BMC (Hexapole) magnet.
If the blue or red point does not converge with the other two
points, perform following steps:
Move BMC magnet (a) to correct insufficient H.static
convergence.
Rotate BMC magnet (b) to correct insufficient V.static
convergence
In either case, repeat Beam Landing Adjustment.
a
BMC magnet
b
V.STAT
Purity
– 16 –
KV-G21L3
RM-883
3. Move the deflection yoke as shown in the figure below and
optimize the convergence.
4. Tighten the deflection yoke screws.
5. Install the deflection yoke spacer.
(2) Dynamic Convergence Adjustment
Preparation :
•
Before starting this adjustment, adjust the horizontal static
convergence and the vertical static convergence.
1. Slightly loosen the deflection yoke screws.
2. Remove the deflection yoke spacer.
(3) Screen-corner Convergence
a-d : screen-corner
misconvergence
misconvergence
b
a
c
d
B G R
B
G
R
R
G
B
R G B
R G B
R
G
B
B
G
R
B G R
R G B
B G R
B G R
R G B
a
d
c
b
Fix a Permalloy assy
corresponding to the
misconverged areas
corresponding to the
misconverged areas
Permalloy assembly
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