Iiyama ProLite XB2483HSU User Manual page 28

Adjust the Phase to correct horizontal wavy noise, fl icker or blur in the zebra pattern.
 In case the strong fl icker or blurs remain on a part of the screen, repeat steps
NOTE
because the Pixel Clock may not be adjusted correctly.
 Adjust the H.Position after the Phase adjustment if the horizontal position moves
during the adjustment.
Adjust the Brightness and Color to get the desired picture after you complete the Pixel
Clock and Phase adjustments.
Put back your favorite wallpaper.
and
OPERATING THE MONITOR 23