Philips 55PP9401 Service Manual page 67

Note: When adjusting the Screen Controls after the Cutoff Adjustment has been completed,
never turn the controls clockwise, as this shortens the life of the CRTs. Always adjust the
Screen Controls counterclockwise following completion of the Cutoff Adjustment.
Adjustment Procedure
1. Enter the I 2 C Adjustment Mode. With power off, press the Source and Power buttons at the
same time, then release. The Service Menu should be displayed.
2. Adjust the Sub-Brightness (Number 2 SUBBRT), using the I 2 C bus alignment procedure so
that only the slightest white portions of the raster can be seen.
3. Exit the Service Menu by pressing the Menu button.
4. Input a grayscale signal into any video input and select that input, using the Source button on
the remote control transmitter or front control panel.
5. Turn the Brightness and Contrast OSD all the way up.
6. Enter the Service Menu again.
7. Make the white areas as white as possible, using the Red DRV (Cool) and Green DRV
(Cool) Drive Adjustment within the I 2 C Service Menu.
8. Set the Brightness and Contrast to minimum.
9. Adjust the low brightness area to black and white, using the Screen Adjustment VRs (red,
green, and blue) on the Focus Pack Assembly.
10. Check the high brightness white areas again. If readjustment is needed, repeat steps 6
through 9. If not, press the Menu key on the remote control transmitter to exit the Service
Menu.
Sub-Picture Amplitude Adjustment
Adjustment Preparation
1. The Sub-Brightness Adjustment should be complete.
2. Begin the adjustment procedure at least 20 minutes after turning on power to the set.
3. Set Contrast to maximum; Brightness to midrange.
4. Press PinP button on the remote control transmitter; PiP should appear on the screen.
5. Select Single Mode.
6. Input an NTSC white signal for the Main Picture and Sub Picture (do not use component
signals).
7. Connect an oscilloscope probe to P852 on the Green CRT board to check the sub-picture
amplitude.
Adjustment Procedure
1. Enter the I 2 C Adjustment Mode.
2. Press the Menu button on the remote control transmitter to scroll through the adjustment
menu pages, until TA1270-M appears at the top of the screen.
7618 Service Adjustments page 36