IBM 4820 - Configuring and Calibrating the Touch Screen

Using Manual Adjust
Normally, you do not need to use Manual Adjust since Auto Adjust sets the
parameters at the optimum default value. However, Manual Adjust allows you to:
v Decrease the screen noise
v Adjust the screen display position and size
To
reduce the noise, adjust the Phase and Clock parameters.
7-2 4820 SurePoint Solution System Reference