Fanuc Power Mate i-D/H Maintenance Manual

The 7.2inch monochrome LCD is provided with a contrast adjustment
potentiometer and video signal adjustment switches.
The contrast is adjusted when the printedcircuit board for LCD or panel
is replaced. Otherwise, it should not be necessary to use the adjustment
7.2inch monochrome LCD (rear view)
(1)Contrast adjustment
Potentiometer VRP1
This adjustment is made to compensate for variations between,
printedcircuit board for LCD and LCD panel. When a printedcircuit
board for LCD or panel is replaced, the following adjustment must be
made. If the entire LCD unit is replaced, however, no adjustment is
(a) First, adjust potentiometer VRP1 until the displayed characters (all
black areas) appear white.
(b)Rotate the potentiometer in the opposite direction until the
characters appear clear and black.
(2)Flicker adjustment
Potentiometer VR1
This potentiometer is factoryset and normally need not be adjusted
by the user. If the setting is changed by mistake, readjust it according
to the following procedure. Note that some versions of this
printedcircuit board do not have this potentiometer; adjustment is
performed automatically.
(a) Using the check pins, observe HS and CLK on an oscilloscope.
(b)Over part of the range of potentiometer VR1, the positivegoing
edge of HS will be almost in phase with the positivegoing edge
of the CLK. Rotating the potentiometer a little does not change the
phase difference. Set the potentiometer to the midpoint of this
(c) After completing the adjustment, confirm that the display does not
7.2inch Monochrome
LCD Adjustment
Adjustment points
Adjustment procedure

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