Adjusting The Dbf Amplitude And Phase - NEC FP1355 Service Manual

2.4.4.4

Adjusting the DBF amplitude and phase

(1) Connect the oscilloscope to the lead of TP-DBF (R7A2 (AG703 side)) on PWB-MAIN and to
one of the signal outputs for the signal sources full R, G, B (VIDEO).
(2) Set the OSD to the select picture of DBF-H-AMP, and using the (-) (+) ADJUST buttons
adjust the horizontal parabola wave amplitude (video area) to the value given in the list of
adjustment values. (Refer to 2.5.1.10 Adjustment value list.)
(3) Set the OSD to the select picture of DBF-H-PHASE, and using the (-) (+) ADJUST buttons
adjust the horizontal parabola wave phase as shown below in respect to the image signal.
(4) Set the OSD to the DBF-V-AMP select picture, and using the (-) (+) ADJUST buttons adjust
the vertical parabola wave amplitude (video area) to the value given in the list of adjust-
ment values. (Refer to 2.5.1.10 Adjustment value list.)
Video signal
Vertical parabola wave
Video signal 1V
DBF-V-AMP adjustment
Horizontal parabola wave
The center of the horizontal
parabola waveform and
center of the image signal
waveform must match.
DBF-H-AMP / PHASE adjustment
2 - 9
Measure
the center.
DBF-V-AMP
DBF-H-PHASE