Sony KV-20S90 Service Manual ▷ View online
— 10 —
KV-20S90 / 21SE43C
The following adjustments should be made when a complete
realignment is required or a new picture tube is installed.
realignment is required or a new picture tube is installed.
These adjustments should be performed with rated power supply
voltage unless otherwise noted.
voltage unless otherwise noted.
Set the controls as follows unless otherwise noted:
VIDEO MODE: Standard
PICTURE CONTROL: Normal
BRIGHTNESS CONTROL: Normal
VIDEO MODE: Standard
PICTURE CONTROL: Normal
BRIGHTNESS CONTROL: Normal
SECTION 2: SET-UP ADJUSTMENTS
Perform the adjustments in order as follows:
1.
Beam Landing
2.
Convergence
3.
Focus
4.
Screen (G2)
5.
White Balance
Note Test Equipment Required:
1.
Color Bar Pattern Generator
2.
Degausser
3.
DC Power Supply
4.
Digital Multimeter
2-1. BEAM LANDING
Before beginning adjustment procedure:
1. Degauss the entire screen.
2. Feed in the white pattern signal.
ADJUSTMENT PROCEDURE
1. Input a raster signal with the pattern generator.
2. Loosen the defl ection yoke mounting screw, and set the purity control
to the center as shown below:
Purity Control
3. Turn the raster signal of the pattern generator to green.
4. Move the defl ection yoke backward, and adjust with the purity control
so that green is in the center and red and blue are even on both
sides.
sides.
Blue
Red
Green
5. Move the defl ection yoke forward, and adjust so that the entire screen
becomes green.
6. Switch over the raster signal to red and blue and confi rm the
condition.
7. When the position of the defl ection yoke is determined, tighten it with
the defl ection yoke mounting screw.
8. If landing at the corner is not right, adjust by using the disk magnets.
a
c
b
d
b
a
c
d
Purity control
corrects this area
Disk magnets
or rotatable disk
magnets correct
these areas (a-d)
Deflection yoke positioning
corrects these areas
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KV-20S90 / 21SE43C
2-2. CONVERGENGE
Before starting convergence adjustments:
1 Perform FOCUS, VLIN and VSIZE adjustments.
2. Set BRIGHTNESS control to minimum.
3. Feed in dot pattern.
VERTICAL STATIC CONVERGENCE
1. Adjust V. STAT magnet to converge red, green and blue dots in the
center of the screen (Vertical movement adjust V.STAT RV701 to
converge).
converge).
B
G
R
Center dot
R G B
V.STAT magnet
2. Tilt the V. STAT magnet and adjust static convergence to open or close
the V. STAT magnet.
When the V. STAT magnet is moved in the direction of arrow a and b,
red, green, and blue dots move as shown below:
B
R
G
B
R
G
R
G B
B
G R
1
2
b
b
b
b
b
b
b
a
a
b
a
a
a
a
3
R
G
B
B
G
R
If the blue dot does not converge with the red and green dots, peform
the following:
1. Move BMC magnet (a) to correct insuffi cient H.Static convergence.
the following:
1. Move BMC magnet (a) to correct insuffi cient H.Static convergence.
2. Rotate BMC magnet (b) to correct insuffi cient V.Static convergence.
3. In either case, repeat Beam Landing Adjustment.
BMC MA
GNET
PURITY
V.STAT
b
BMC magnet
a
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KV-20S90 / 21SE43C
DYNAMIC CONVERGENCE ADJUSTMENT
Before performing this adjustment, perform Horizontal and Vertical Static
Convergence Adjustment.
1. Slightly loosen defl ection yoke screw.
Convergence Adjustment.
1. Slightly loosen defl ection yoke screw.
2. Remove defl ection yoke spacers.
3. Move the defl ection yoke for best convergence as
shown below:
R G B B G R
R G B
R
R
R
G
B
G
B
G
B
R G B
B G R
R
G
B
R
G
B
B G R R G B
4. Tighten the defl ection yoke screw.
5. Install the defl ection yoke spacers.
SCREEN-CORNER CONVERGENCE
1. Affi x a permalloy assembly corresponding to the misconverged areas:
b
a
c
d
a
b
a-d: screen-corner
misconvergence
c
d
2-3. FOCUS
1. Adjust FOCUS control for best pictures.
2-4. SCREEN (G2)
1. Input a dot pattern.
2. Set the PICTURE and BRIGHTNESS controls at minimum and
COLOR control at normal.
3. Adjust SBRT, GCUT, BCUT in service mode with an oscilloscope as
shown below so that voltages on the red, green, and blue cathodes
are 170 ± 2 VDC.
are 170 ± 2 VDC.
pedestal
GND
170 ± 2 VDC
4. Observe the screen and adjust SCREEN (G2) VR to obtain the faintly
visible background of dot signal.
Focus (FV)
Screen (G2)
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KV-20S90 / 21SE43C
2-5. METHOD OF SETTING THE SERVICE
ADJUSTMENT MODE
ADJUSTMENT MODE
SERVICE MODE PROCEDURE
1. Standby mode (power off).
2. Press Display
Channel 5
Sound Volume +
Power
on the Remote Commander (press each button within a second).
SERVICE ADJUSTMENT MODE IN
1. The CRT displays the time being adjusted.
Mode
Display
Item
Item
Data
SERVICE
HSIZ
0
2. Press 1 or 4 on the Remote Commander to select the time.
3. Press 3 or 6 on the Remote Commander to change the data.
4. Press MUTING then ENTER to save into the memory.
SERVICE ADJUSTMENT MODE MEMORY
Turn the set off then on to exit Service Adjustment Mode.
Mode
WRITE
ENTER
Green
Red
MUTING
SERVICE
2-6. WHITE BALANCE ADJUSTMENTS
1. Input an entire white signal.
2. Set to Service Adjustment Mode.
3. Set DCOL to “0”.
4. Set the PICTURE and BRIGHTNESS to minimum.
5. Adjust with SBRT if necessary.
6. Select GCUT and BCUT with 1 and 4 .
7. Adjust with 3 and 6 for the best white balance.
8. Set the PICTURE and BRIGHTNESS to maximum.
9. Select GDRV and BDRV with 1 and 4 .
10. Adjust with 3 and 6 for the best white balance.
11. Reset DCOL to “1”.
12. To write into memory, press MUTING then ENTER .
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