Excuse the crudeness here, took a screenshot from Asteroids on KLOV and drew some lines on it to illustrate what's going on with my monitor.
On most screens, I get these thin lines that scroll across my screen, almost like some kind of interferrence. They're much easier to see on darker backgrounds, and almost unbearable when playing Asteroids and other vector games. It seems to be happening at all resolutions.
I have a Wells Gardiner K7600 monitor running on an ArcadeVGA and a J-Pac.
Has anyone ever seen something like this before?