In my task I'm employing a CM2009 IC between precise VGA controller and VGA output connector. It's pointed out in the datasheet for this IC which i can use EMI filters on HSYNC, VSYNC and DDC channels suitable immediately after IC and just before VGA connector. Though there isn't any https://paxtonlidxr.blogsumer.com/30653705/getting-my-ac-emi-filter-to-work