Dell S300wi User Manual page 53

F —Allows you to change the display data clock frequency to match the
REQUENCY
frequency of your computer graphics card. If you see a vertical flickering wave, use
Frequency control to minimize the bars. This is a coarse adjustment.
T —Synchronize the phase of the display signal with the graphic card. If you
RACKING
experience an unstable or flickering image, use Tracking to correct it. This is a fine
adjustment.
50
Using Your Projector