I am troubleshooting an application with the ADV7441A. In auto graphics mode (either analog or digital grapics), any mode with a pixel clock between 72-76 MHz is showing horizontal HF noise, almost like the pixel clock is unstable. The modes tested that show this problem are 720p, 1080i, and XGA at 70Hz. This has been observed on 8 first run boards. Can anyone offer guidance on what may be going on here?
The application uses many of the register settings from the ADV7441A evaluation board.