Why is my screen very dim or sometimes even blank?

The backlight of the flat panel display may not be active. A software bug in KTE Interactive version 4.3.2 sometimes prevents the backlight of the flat panel display from being turned back on after the screen saver is exited. Installing Service Pack 1 (SP1) for KTE Interactive version 4.3.2 will correct this problem. Contact Keithley service for an SP1 installation CD.