Sony KV-28DC20B Service Manual ▷ View online
21
H M C c o r r e c t i o n ( A )
H M C c o r r e c t i o n ( B )
A < B
A = B
R G
B
R G B
A > B
A = B
R
G B
R G B
Fig.3-4
Fig. 3-5
3-2. CONVERGENCE
(1)
Screen centre convergence
[Static convergence]
[Static convergence]
1.
Input a dot signal from the pattern generator.
2.
Normalize the picture setting.
3.
[Moving vertically], adjust the V.STAT magnet so that the
vertical red, green and blue dots coincide at the centre of the
screen.
vertical red, green and blue dots coincide at the centre of the
screen.
By opening or closing the V.STAT magnet, the red, green and
blue dots move as indicated below.
blue dots move as indicated below.
Note: Do not adjust the H.STAT by rotating the V.STAT
magnets as this can affect the focus setting.
magnets as this can affect the focus setting.
4.
Correction for HMC [horizontal mis-convergence] and
VMC [vertical mis-convergence] by using the BMC
[Hexapole] magnet.
VMC [vertical mis-convergence] by using the BMC
[Hexapole] magnet.
a).
HMC correction by BMC [Hexapole] magnet and movement
of the electron beam.
of the electron beam.
Purity control corrects
this area
this area
Disk magnets or
rotatable disk
magnets correct
these areas (a-d)
rotatable disk
magnets correct
these areas (a-d)
Deflection yoke positioning
corrects these areas
corrects these areas
a
c
d
b
Disk Magnets
H.STAT
convergence
control
V.STAT
vertical static magnet
Center dot
H.STAT VR on
mount side
H.STAT convergence
B
G
R
B
G
R
GREEN
BLUE
RED
22
b).
VMC correction by BMC [Hexapole] magnet and movement
of the electron beam.
of the electron beam.
HAMP
6.
HTIL correction can be performed by adding a THL correction
ASSY to the DY.
ASSY to the DY.
TLH correction Assy
4-057-714-01
HTIL
Fig 3-6
Note :
If you are unable to adjust the corner convergence
properly, this can be corrected with the use of
permalloys.
properly, this can be corrected with the use of
permalloys.
C < D
C = D
C > D
C = D
R
G
G
B
C
D
C
D
R
G
B
R
G
B
R
G
B
V M C c o r r e c t i o n ( A )
V M C c o r r e c t i o n ( B )
LAYOUT OF EACH CONTROL
Y-splitting axis correction magnet
V STAT convergence magnet
BMC (Hexaploe) magnet
Purity magnet
a-d: screen-corner
convergence defect
convergence defect
a
b
c
d
Permalloy Assy
X-4387-214-1
X-4387-214-1
Convergence adjustment with permalloy.
23
3-3. SCREEN (G2)
1.
Input a dot signal from the pattern generator.
2.
Set the Picture, Brightness and Colour to minimum.
3.
Apply 175V DC from an external power supply to the
R, G and B cathodes of the CRT.
R, G and B cathodes of the CRT.
4.
Whilst watching the picture, adjust [SCREEN G2] located on
the FBT [flyback transformer] to the point just before the
flyback return lines disappear.
the FBT [flyback transformer] to the point just before the
flyback return lines disappear.
3-4. FOCUS
1.
Receive a television broadcast signal.
2.
Normalise the picture setting.
3
Adjust the focus control located on the FBT [flyback
transformer] to obtain the best focus at the centre of the screen.
Bring only the centre area of the screen into focus, the
magenta-ring appears on the screen. In this case, adjust the
focus to optimize the screen uniformly.
transformer] to obtain the best focus at the centre of the screen.
Bring only the centre area of the screen into focus, the
magenta-ring appears on the screen. In this case, adjust the
focus to optimize the screen uniformly.
3-5. WHITE BALANCE
1.
Input an all white signal from the pattern generator.
2.
Enter into the Service Mode.
3.
Enter into the ‘Picture Adjustment’ service menu.
4.
Select ‘Sub contrast’ and adjust to 7.
5.
Select the ‘Green drive’ and adjust so that the white balance
becomes optimum.
becomes optimum.
6.
Select the ‘Blue drive’ and adjust so that the white balance
becomes optimum.
becomes optimum.
7.
Press the ‘TV’ button on the remote commander to return to
TV operation.
SCREEN G2 ADJUSTMENT
WHITE BALANCE ADJUSTMENT
FOCUS
SCREEN (G2)
24
SECTION 4
CIRCUIT ADJUSTMENTS
5
+
+
(ON SCREEN
DISPLAY)
DISPLAY)
(DIGIT 5)
(VOLUME
+
)
(TV)
4-1. ELECTRICAL ADJUSTMENTS
Service adjustments to this model can be performed
using the supplied Remote Commander RM-931.
using the supplied Remote Commander RM-931.
1.
Turn on the main power switch and enter into the stand-by
mode.
mode.
2.
Press the following sequence of buttons on the Remote
Commander.
Commander.
•
‘TT--’ will appear in the upper right corner of the
screen.
Other status information will also be displayed.
screen.
Other status information will also be displayed.
3.
Press ‘MENU’ on the remote commander to obtain the
following menu on the screen.
following menu on the screen.
4.
Move to the corresponding adjustment using the Up/Down
Arrow button on the remote commander.
Arrow button on the remote commander.
5.
Press the Right Arrow button to enter the selected adjustment.
6.
Turn off the power to quit the service mode when adjustments
have been completed.
have been completed.
HOW TO ENTER INTO SERVICE MODE
TEST MENU
> Picture Adjustment
Geometry
Wide
IC status
MSP
Dynamic Convergence
Current TV status
PICTURE ADJUSTMENT
AFC mode
1
REF position
1
SCP BGR
1
SCP BGF
1
Trap fo
10
Sub contrast
Adj
Sub colour
Adj
Sub brightness
Adj
Green drive
Adj
Blue drive
Adj
Green cutoff
Adj
Blue cutoff
Adj
Gamma
0
Pre / overshoot
3
Y delay
2
D Pic
ON
D Colour
OFF
DC Transfer
OFF
GEOMETRY ADJUSTMENT - 4:3
V size
Adj
V position
Adj
S Correction
Adj
V Linearity
Adj
H size
Adj
H position
Adj
Pin Amp
Adj
Pin Phase
Adj
AFC Bow
Adj
AFC Angle
Adj
EHT V
1
EHT H
0
Lo Corn Pin
Adj
Up Corn Pin
Adj
WIDE ADJUSTMENT - 4:3
V Aspect
0
V Scroll
31
Upper V Lin
0
Lower V Lin
0
Left Blanking
7
Right Blanking
7
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