Today my backup PS/1 monitor has started to fail. All video modes except 640x480 have a sync problem that makes the monitor unusable. But in 640x480 the image is sharp, clean and free of any sync problems. I'm totally lost, if the VGA cord was in bad state the sync problem would affect all video modes. Here is a video (it doesn't really show the unsynchronised image as it is, the image rolls very fast but it seems that the videocamera and youtube have lost a lot of frames):
Any idea?
Any idea?