SONY KV25X5B
Instrukcja Serwisowa

KV-25X5

(4)
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Screen corner convergence.
If you are unable to adjust the corner convergence properly, this can be corrected by the use of permalloy assemblies.

3-3. Screen [G2], White balance
G2 Setting
1. 2. 3. 4. Input a dot signal from the pattern generator. Set the Picture, Brightness and Colour to minimum. Apply 170Vdc from an external power supply to the R, G and B cathodes of the CRT. 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.

a a-d: screen-corner convergence defect c

b

d

White balance adjustment
1. 2. 3. 4. 5. 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. Set the Picture to MIN. Set the �R-cut-off� to 07. Adjust the �G-cut-off�, and the �B-cut-off� so that the White Balance becomes optimum. Press the button to return to TV operation.

Fit the permalloy assembly to the rear of the CRT to correct the area at fault.
a

6. 7. 8. 10.

b

PICTURE

R - Drive G - Drive Permalloy
c d

Adj Adj Adj Adj Adj Adj 02 01 01 Adj Adj Adj

B - Drive R - cut - off G - cut - off B - cut - off ID - start ID - stop ID - level Bellfo Sub Colour Sub Brightness

3-4. FOCUS
1. 2. 3.
FOCUS

Input a Phillips colour pattern Set the picture settings to normal. Adjust the focus control located on the Flyback transformer to bring the centre of the screen into focus. Note :Bring only the centre area of the screen into focus, switch to an all-white pattern and confirm that the magenta ring is hardly noticed. To obtain optimum focus balance the focus setting between optimum screen centre focus and a reduced magenta ring level.

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