Panasonic TH-P42U30Z Service Manual page 28

Another procedure
Connect IIC cable (bus controller-cable) after banner OSD appear.
And after SRQ-L, begin an adjustment 2 seconds later.
Adjustment of HD system
1. At 1080i 100% Full White or Split colour bar receive component signal, as shown below.
2. Goes into service mode.
3. Push [ 1 ] or [ 2 ] key, and goes into adjustment mode for [ Contrast ].
Adjustment
1. The colour key yellow button of remote control is pushed.
2. The OSD character of sub-contrast becomes red.
(Inside under automatic adjustment)
3. The OSD character of sub-contrast returns to black.
When [NG] is displayed, adjustment failure.
4. End.
Steps
28
Remarks