The CRT "Daq" should be grounded. The CRT is coated with a conductive
material (black material you see from the back) which usualy has a spring
surrounding the tube. This spring has a wire connected to it. That wire goes
to the ground (line cord) either directly or through a low value resistance.
Check continuity from the "Daq" to the ground prong of the line cord. Also
check the wall receptical for a good ground!