Philco 113020208, Service Manual

Page: 16 / 30

-16- -16-
Service Adjustments
Items 35-42 GREY SCALE
1. Receive a monochrome circular pattern.
2. Set the brightness and colour to normal, contrast to maximum.
3. Enter to the service mode.
4. Set Item- 54 RBIAS, 55 GBIAS and 56 BBIAS mode to 03, 1E and 02. Set Item- 57 RDRV and 58 GDRV mode to
42 and 38, 59 BDRV to 3C.
5. Select Item- 60 mode to be one horizontal scanning line and turn the screen volume on the FBT to obtain just vis-
ible one coloured line.
6. Press the 1 (Red Bias +) , 4 (Red Bias -) , 2 (Green Bias +) , 5 (Green Bias -) , 3 (Blue Bias +) or 6 (Blue Bias -)
button to adjust the brightness of each colour until a dim white line produced. Please see the control button alloca-
tions in this mode.
7. Select Item- 61 DRV mode to enter the white balance adjusting mode.
8. Press the 7 (Red Drive +) , RECALL (Red Drive -) , 8 (Green Drive +), 0 (Green Drive -), 9 (Blue Drive +) or
SLEEP (Blue Drive -) button alternately to produce normal black and white picture.
9. Exit from the service mode.
10. Check for proper grey scale tracking at all brightness levels.
NOTE: If the grey scale adjustment is made after picture tube replacement, check the high voltage.
Red Bias -
Red Bias +
Green Bias -
Blue Bias +
Green Drive -
Green Drive +
Green Bias +
Blue Bias -
Press the MENU but-
ton to exit from service
mode
Red Drive -
Blue Drive +
Blue Drive -
Red Drive +
MAIN BOARD
SCREEN VR
(Under side)