This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.
Arcing from the metal brace to the HV module can cause the display to momentarily shrink and flick out of focus. Follow safety and setup procedures outlined earlier. The cure is to bend the brace up enough to increase the arc path and clean the surfaces involved. Apply HV dope to the brace and module where distances are small. If the case interior seems pretty clogged with dust and gunk, it's a good idea to remove the side-mounted Controls/Switch (C/S) Module and give the case a good washing. (Be very sure it is well dried before replacing.) You should also clean the two controls on the C/S Module with spray-in Control Cleaner. Before putting the case back, this may be a good time to adjust base Intensity and Focus (the two nub controls on the HV module). Position the monitor so that screen is easy to see and the nub controls are accessible. Plug in the the C/S Module. Adjust the C/S Module controls to center positions. Plug in the monitor to the computer. Get a Desktop display with some text and icons. Use an insulated tool to adjust the nub Intensity and Focus controls for maximum sharpness at 'normal' viewing intensity. A magnifying glass is helpful to obtain max pixel sharpness. By: Rubywand = = = = = = = = = = = = = =