3-3. Focus
1. Receive a television broadcast signal. 2. Normalize the picture setting. 3. Adjust the focus control on the flyback transformer for the best focus at the center of the screen. Bring only the center area of the screen into focus, the magenta-ring appears on the screen. In this case, adjust the focus to optimize the screen uniformly.
Item No 1 2 3 4 5 6 7 8 9 10
Video Proc. TDA4780
Adjustment item BRT COL PIC HUE R GAIN G GAIN B GAIN R LVL REF G LVL REF B LVL REF PEAK DRV LIMIT GAMMA SCP ON = 3LEV OFF = 2LEV DELAY Data Amount USER CONTROL USER CONTROL USER CONTROL USER CONTROL 31 Adj Adj 31 Adj Adj 63 31 ON OF F
FOCUS
11 12 13 14
3-4. Screen (G2), White balance (Adjustment in the service mode with remote commander)
G2 adjustment (RV701)
1. Input a dot signal from the pattern generator. 2. Set the Picture, Brightness and Colour to minimum. 3. Apply 170V DC from an external power supply to the R, G and B cathodes of the CRT. 4. While watching the picture, adjust the G2 control RV701 [ SCREEN ] on the C board to the point just before the return lines disappear.
5. Set picture to MAX. 6. Set the ' R GAIN ' to 25. 7. Adjust the ' G GAIN ' and ' B GAIN ' so that the white balance becomes optimum. 8. Press the OK button to write the data for each item. 9. Set picture to MIN. 10. Set the ' R LVL REF ' to 31. 11. Adjust ' G LVL REF ', and ' B LVL REF ' with the left and right buttons so that the white balance becomes optimum. 12. Press the OK button to write the data for each item.
White balance adjustment
1. Receive an all-white signal. 2. Enter into the Service Mode by pressing ' TEST ', ' TEST ' and ' MENU' on the Service Commander. 3. Select ' VIDEO PROC. ' from the on screen menu display and press OK . 4. The ' VIDEO PROC TDA4780' menu will appear on the screen.
