Screen [G2] White Balance; Focus - Sony TRINITRON KV-25K5A Service Manual

Screen corner convergence.
If you are unable to adjust the corner convergence properly,
this can be corrected by the use of permalloy assemblies.
Fit the permalloy assembly to the rear
of the CRT to correct the area at fault.
KV-25K5/29K5
3-3. Screen [G2], White balance
Input a dot signal from the pattern generator.
—
2. Set the Picture, Brightness and Colour to minimum.
3. Apply 170Vdc from an external power supply to the
R, G and B cathodes of the CRT.
4. Whilst watching the picture, adjust the G2 control [RV701
SCREEN] located on the C Board to the point just before the
flyback return lines disappear.
White balance adjustment
Input a 'PAL' all-white signal from the pattern generator.
Enter into the Service Mode.
Enter into the 'Picture' service menu.
Select the 'Green drive' and adjust so that the White Balance
becomes optimum.
Select the 'Blue drive' and adjust so that the White Balance
becomes optimum.
6. Set the Picture to MIN.
7. Set the 'R-cut-off' to 07.
8. Adjust the 'G-cut-off', and the 'B-cut-off' so that the White
Balance becomes optimum.
10. Press the © button to return to TV operation.
PICTURE
AoNe
wn
R - Drive Adj
G - Drive Adj
B - Drive Adj
R - cut - off Adj
G - cut - off Adj
B - cut - off Adj
!D - start 02
ID - stop 01
ID - level 01
Bellfo Adj
Sub Colour Adj
Sub Brightness Adj
3-4. FOCUS
L. Input a Phillips colour pattern
2. Set the picture settings to normal.
3. Adjust the focus contro! located on the Flyback ta nsformer to
bring the centre of the screen into focus.
Note :Bring only the centre area of the screen into focu;, switch to an
all-white pattern and confirm that the magenta ring is hardly
noticed. To obtain optimum focus balance the fouss setting
between optimum screen centre focus and a redweed magenta
ring level.
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